1) Differences in Mirror Neuron System (MNS) activation in response to dynamic emotional stimuli
Chengetai Charidza and Helge Gillmeister (University of Essex)
The ability to simulate the motor properties of emotional body language has been largely associated with empathy and the observation-execution matching properties of the mirror neuron system (MNS). A purported index of MNS activity is the mu rhythm, which is comprised of sensorimotor alpha and beta oscillations. This study investigated whether event-related desynchronisation (ERD) of mu alpha (7.5 – 12.5 Hz) and mu beta (12.5 – 30 Hz) would differentiate between different emotional facial expressions. Participants watched videos showing face models act out the six basic emotions (anger, disgust, fear, happiness, sadness and surprise). Mu alpha distinguished between anger, disgust and fear, with greater ERD for disgust than for anger or fear over frontal midline electrodes. Mu beta distinguished between happiness and sadness, with greater ERD for happiness than sadness over superior parietal electrodes. These findings suggest that sensorimotor simulation, as indexed by mu, is more sensitive to certain emotional stimuli and may play a role in emotion recognition. In a follow up study, we further investigated whether mu oscillatory indices of emotional processing would differ in high trait anxiety individuals, as such individuals show cognitive and neural biases toward negative emotional stimuli in particular.
2) Evidence of loss aversion during effort-based decision-making
Xiuli Chen, Henry Marks, Lilian Berenyi and Joseph M.Galea (University of Birmingham)
Due to the prevalence of disorders that show a diminished willingness to exert effort (e.g. depression, Parkinson’s disease, stroke), there is increasing interest on effort-based decision-making in which humans evaluate the trade-off between benefits and motor costs. It is unknown whether loss aversion (tendency to prefer avoiding losses to acquiring equivalent gains) is apparent during effort-based decision-making. On the one hand, as distinct brain regions appear to subserve choices based on effort and value, similar dichotomies between reward and punishment may not exist. On the other hand, loss aversion is hardwired due to asymmetric evolutionary pressure on losses and gains, and thus may exist during effort-based decision-making. To examine this, participants (N=24) were asked to make a series of choices about whether to produce a required force to either gain or to avoid losing points. The amount of force required on each trial varied (one of 15%, 25%, 35%, 45%, 55%,65% of maximal voluntary effort). The amount of points offered was based on adaptive procedures given their previous choices. As expected, participants demanded more points for increasing physical effort in both conditions. Interestingly, only at the higher force levels (45%-65%), participants demanded higher points in reward than punishment condition to engage in the same force level (loss aversion). In addition, the time to decide between options was longer when rejecting a force option (forgoing rewards or accepting punishments) than when accepting a force option (gaining rewards, avoiding punishments). Crucially, this difference was greater in the punishment condition, suggesting a greater sensitivity to loss. These results indicate that loss aversion is clearly evident during effort-based decision-making, which coult have important implications for developing novel interventions to overcome the diminished willingness to exert effort in a range of clinical disorders.
3) Concomitant but dissociable effect of reward on selection and execution components of motor control
Olivier Codol, Peter J. Holland and Joseph M. Galea (University of Birmingham)
When performing a movement, performance usually depends on whether the optimal action was selected and if that action is executed properly. Both of these components can show improvements during learning, and usually rely on overlapping but distinct anatomical circuits in the brain. Much evidence now shows that reward promotes learning in action selection [1,2], while it increases vigour in the execution component of a movement [3]. While these effects have been well documented, no study managed to dissociate the effect of reward on action selection and execution during the same motor task (4). Specifically, we addressed here whether any, or both these components benefit from the introduction of performance-based monetary reward. The task consisted of reaching to a target as fast as possible, with faster reaction times and movement times being rewarded with 0 to 50p per trials proportionally to performance. Distracting targets were occasionally introduced to induce a selection component to the task. First, a strong increase in movement peak velocity was observed in rewarded trials as opposed to non-rewarded trials, despite similar radial errors to target. However, this led to an asymmetric shift in the speed-accuracy function, with only very fast movements displaying reward-induced effects. On the other hand, while selection speed (reaction times) remained the same across reward magnitudes, selection accuracy (proportion of distracted trials) drastically improved in rewarded trials compared to 0p trials, regardless of reward magnitude. This also translated in a clear shift in the selection speed-accuracy function across the whole range of reaction times expressed. These results suggest that our task successfully isolates selection and execution components in motor control and that reward plays a strong, but dissociable role in each of these components.
4) Pre-stimulus EEG alpha power and its relation with subjective perceptual awareness
Andra Coldea, Christopher S.Y. Benwell, Monika Harvey and Gregor Thut (University of Glasgow)
The state of neural excitability at the time of presenting a sensory stimulus strongly influences its perception. Previous studies have shown that the power of ongoing oscillatory alpha band activity predicts whether an upcoming weak visual stimulus will be detected or not. It is unclear how baseline oscillatory activity modulates performance, but it has been recently suggested that alpha power modulates changes in detection criterion (i.e. low alpha power causes an increase in the tendency to report a stimulus regardless of its presence) and not in visual sensitivity as previously thought. We recorded EEG whilst participants performed a single visual stimulus identification task in combination with single-trial ratings of perceptual awareness. The aim of the present study was to assess whether the power and frequency of pre-stimulus oscillatory activity is related to objective performance (i.e. discrimination accuracy) and/or subjective perceptual awareness on a trial-by-trial basis. In addition, this relationship has been investigated using psychophysical testing based on Bundesen’s Theory of Visual Attention (TVA; Bundesen, 1990). Pre-stimulus power centred in the alpha band (8-14 Hz) was inversely related to perceptual awareness ratings, but did not predict discrimination accuracy. In addition, no significant relationships were found between EEG power and the TVA parameters of interest. Altogether, these results provide evidence that pre-stimulus alpha power is closely linked to ratings of subjective perceptual awareness, but does not influence the visual sensitivity when a decision is made about a stimulus feature. Thus, a clear dissociation between has been found between the influence of ongoing oscillatory alpha band activity on perceptual awareness and objective performance.
5) How does the form of feedback influence the way we process the message?
Chelsea Dainton, Bertram Opitz and Naomi Winstone (University of Surrey)
Within education, both Evaluative Feedback (EF; how you have performed) and Directive Feedback (DF; how to improve in future) are used to promote learning. A recent study by Nash et al. (in press) has shown that DF, though more often requested by students, is often forgotten or misremembered in a recall task compared to EF. This study investigated whether differences in the ease of decoding (with EF being easier to decode) and utility (with DF providing more utility) of feedback could explain this paradox. Electroencephalogram (EEG) measures were utilised by the researchers to understand whether underlying brain processes can explain this difference in behaviour. The feedback related negativity (FRN) signal is an event related potential that is used to measure feedback processing. However, no study has yet measured DF using these measures. Thus, the current study aimed to investigate whether DF produced an FRN signal similar to that of EF, and whether this component is sensitive to the ease of decoding or utility of feedback provided. Behavioural results highlighted confirmed the importance of both factors on performance. Feedback that was easy to decode and easy to utilise produced the highest accuracy and fastest reaction times, whilst the easy to decode but hard to utilise feedback produced the lowest accuracy and slowest reaction time. Within the EEG data a signal similar to the FRN was found in DF which exhibited sensitivity to ease of decoding and utility of feedback. Explanations for these findings and suggestions for future research are discussed.
6) Impaired language networks in Internet addiction: Verbal fluency task-related fMRI study
Gergely Darnai, Gabor Perlaki, Gergely Orsi, Andras Zsido, Orsolya Inhof, Beatrix Labadi, Szabolcs Ajtony Bandi, Nikolett Arato, Timea Budai and Jozsef Janszky (University of Pecs, Hungary; Pecs Diagnostic Centre, Hungary; Szentagothai Research Center, Hungary)
Internet addiction is becoming an important mental issue. Earlier studies revealed that the excessive use of Internet can lead to increased loneliness, reduced communication and social skills, decreased intra-familial participation, depression, and poorer mental health [1,2]. However, the exact brain-related mechanisms behind these phenomena are still unclear. Since we claim that impaired language processing might be the primary reason, our aim was to study if alterations in language networks are related to Internet addiction. Methods. Sixty healthy, young, right-handed healthy university students were included. They underwent a block-designed phonological verbal fluency task during BOLD-contrast imaging in 3T Siemens MRI scanner and completed the Problematic Internet Use Questionnaire [3]. Three subscale scores (Neglect, Control, and Obsession) and Total score were calculated. Task-related activations were assessed using model free (T-PICA) and model-based (GLM) analyses. Results. We found two components (C3 and C4) that were related to Control subscale and Total scores. C3 contains areas that play important role in language processing including the left inferior frontal gyrus (pars opercularis), left supramarginal gyrus, left precentral gyrus and left middle frontal gyrus. According to the GLM analysis, Control subscale was related to activations in the left pre- and postcentral gyri. Conclusions. According to our results, Internet addiction is related to altered language network and this relationship might explain some comorbid symptoms related to Internet addiction.
7) Cross-modal contextual effects from vision to touch
Cristina Denk-Florea, Andrew T. Morgan, Lucy S. Petro and Lars Muckli (University of Glasgow)
Activity in early somatosensory cortex (S1) is influenced by other sensory systems. Although this phenomenon was explained in the context of cross-modal contextual effects, the majority of evidence is speculative. In this fMRI study we investigated using multivariate pattern analyses whether joint multi-sensory experience (visual-haptic) with novel objects from two categories will lead to the decoding of the objects in S1 during unimodal visual presentation of images of the objects. In this study we were also interested to observe if cross-modal contextual effects in S1 extend to familiar natural scene images. According to the neural representation of perceptual experience theory we anticipated the objects and scenes to be decoded in S1. The participants (N= 10) were split in two groups, only one of the groups having visual-haptic experience with the objects. In the MRI scanner all participants viewed identical images. We discovered that we could only decode between two object pairs in the group who had visual-haptic experience with the objects and one pair of objects in the group who had no visual-haptic experience with the objects. However, our results indicate a trend, the decoding of the objects being generally higher in the group of participants who had visual-haptic experience with the objects. We discuss our findings in the context of stimuli limitations in inducing tactile predictions, the study being underpowered, as well as unaccounted mechanisms which might have influenced the results. Our results contribute to gaining a better understanding of multi-sensory processing and joint multi-sensory experience in modulating the activity in S1.
8) The influence of top down contextual predictions on the processing of degraded feedforward information
Gemma Donnelly, Johanna Bergmann, Matthew Bennett, Lucy Petro and Lars Muckli (University of Glasgow)
The brain uses contextual information to form predictions about input. When input is weak or ambiguous, context can aid processing. Previously, we investigated activity in early visual cortex while processing partially occluded images. Activation patterns revealed top-down predictions are sent to V1. Here we investigate how contextual information facilitates detection and recognition of visual input. With a behavioural experiment, we investigated how top-down predictions influence the processing of low-contrast input. Instead of occluding a region entirely, low contrast stimuli shone through the occlusion – like viewing behind a frosted screen. In expt-1, the lower right quadrant, our target region, of a scene, was shown at 8 low contrast levels. The surrounding full-contrast quadrants were either consistent with the target region, inconsistent or absent. Subjects identified whether the target contained a scene (detection task) and whether this scene was natural or man-made (identification task). Results show that when surround and target regions are consistent identification accuracies are higher than when the surround is absent. When the target and surround are inconsistent, accuracies drop to below chance, indicating an interference from top-down predictions. Detection does not differ with different surround input. To further test this contextual effect we conducted expt-2 using 7 contrast levels around the perceptual threshold. Again, detection rates remain stable across conditions but identification accuracies differ, indicating that consistent information is recognised easier than inconsistent. This suggests contextual predictions influence identification but not detection of stimuli. Our results show top-down predictions facilitate the processing of weak feedforward information consistent with these predictions and interfere with that of inconsistent input and are in line with the notion of neuronal sharpening of representations of predicted stimuli.
9) Investigating embodied representations of emotional expressions in ASD: A study with SEPs
Martina Fanghella, Beatriz Calvo Merino, Sebastian Gaigg, Matteo Candidi, Salvatore Maria Aglioti (Sapienza, University of Rome, Italy; City, University of London)
Autism Spectrum Disorder (ASD) is a neurodevelopmental condition characterised by difficulties in social interaction and communication, as well as repetitive and restricted patterns of behaviour and interests (American Psychiatric Association, 2000). Recent research suggests that differences in embodied representations of emotional expressions might play a role in ASD. For instance, several empirical studies show that recognition of emotional expressions [3], interoception [2] and physiological responses to social stimuli [4] function differently in ASD individuals. However, the neural mechanisms involved in atypical embodied representations of emotional expression in ASD has not been systematically investigated. Recent research highlights that visual perception of faces and bodies in typical population is accompanied by parallel activity of visual and somatosensory areas [1, 5-8]. Our EEG study provides the first direct measurement of the activity of the somatosensory cortex during perception of facial emotional expressions in ASD individuals. Our methodology combines Visual and Somatosensory Evoked Potentials (VEPs and SEPs), to isolate effects driven by somatosensory or visual processing. This methodology has already provided evidence of unique contributions of the somatosensory cortex in processing emotional expressions by Sel et al [8] and we are now interested in investigating whether ASD population show different patterns of neural response compared to typical individuals. We are analyzing responses in visual and somatosensory cortical areas in a group of ASD and a control TD participants while they perform a visual emotion recognition task and a control gender recognition task. We predict a modulation of somatosensory evoked potentials driven by emotional expressions processing but not by gender. Moreover, we expect to observe a significant difference in this effect across the two groups.
10) Individual differences in sensory integration predict differences in time perception
Ben Fenner, Gethin Hughes, Nick Cooper and Vincenzo Romei (University of Essex; University of Bologna, Italy)
There is good evidence that individual differences in the temporal resolution of sensory integration relates to significant differences in perception, at extremes relating to conditions such as schizophrenia [1]. Increasingly neural evidence suggests that elements of time perception are embedded within sensory systems [2] however there is little available evidence as to whether, and how, this is influenced by individual differences in the rate of sensory integration. We address this by comparing individual Temporal Binding Windows (TBW; estimated via an adaption of the Simultaneity Judgement task) with individual differences in the filled duration illusion. The filled duration illusion is where intervals filled with a tone reliably appear longer than those where only onset and offset are signalled. Furthermore, we look to establish whether this can be dissociated form the global perceptual differences as found in Schizotypy (measured by the O-life survey). Findings from a large sample (N=103) confirm the filled duration illusion and significantly relate the magnitude of the effect to the size of the TBW. Schizotypy relates only to the TBW. This provides evidence that individual differences in rate of sensory integration relate to time perception, suggesting opportunities for new research.
11) Falling for it: The effects of anxiety on balance control
Anna Fielding (Brunel University)
Heightened Fear of Falling (FOF) leads to increased reliance on vision [1;2;3] and changes in balance-correcting responses [4], which leads to increased fall risk and significant costs for older adults (OAs) [5;6;7]. It remains unclear how anxiety affects these physiological responses. This study investigated this process in two age groups (young adults [YAs; n=31] & OAs[n=31]) by inducing height-related threat using virtual reality. Participants stood on a forceplate and experienced a virtual environment; either standing at the top of a cliff (Threat condition) or at ground level (Baseline). For one single trial in each condition, after a short period of standing in the environment the visual scene was rotated backward to create an optic flow simulation consistent with the visual experience of swaying backwards i.e. losing one’s balance. State anxiety and magnitude of postural sway was measured in both Threat and Baseline conditions following the visual perturbation. Both groups reported similarly significantly increased anxiety during Threat condition compared with Baseline. Analysis on a pooled sample revealed significantly increased range of sway at cliff compared to ground; OAs’ range of sway was significantly higher than YAs. However, a significant correlation of the change in anxiety between Baseline and Threat conditions and the associated sway response was only found in YAs, suggesting that the height effect is driven primarily by changes observed in YAs. Thus, while anxiety does appear to be causally related with increased reliance on vison to control balance, it does not fully account for greater reliance on vision in OAs. These results support previous findings that anxiety increases visual reliance for balance control in YAs [8], and elucidate age differences in how balance is maintained during increased anxiety. Future research aims to specify factors contributing to visual reliance in OAs as well as other factors that might influence fall risk.
12) Extraordinary bodies: How the brain perceives persons with physical disabilities
Helge Gillmeister, Roxanne Armstrong-Moore, Geraldine Goldstein and Chris Devereux-Cooke (University of Essex)
Recent claims have linked perceptual processing styles (configural vs. feature-based) with the (sexual) objectification and dehumanisation of lower-status groups (e.g. women). We combined ERPs and behavioural methods to test this claim, comparing the perception of two groups of disabilities (missing limbs, postural abnormalities) with that of typical bodies in comparably asymmetrical configurations. We used the body inversion effect (BIE) as an index of perceptual processing style, with expected differences in performance for upright (predominantly configurally processed) and inverted (predominantly featurally processed) visual stimuli. Results suggest that, even when upright, bodies with missing limbs in particular are perceived predominantly on the basis of local features rather than configurally, as shown by reduced BIEs in both brain (P1-N1, P2-P3 waves) and behaviour. Disabled bodies also elicited enhanced occipitotemporal scalp positivities at early, perceptual (P1-N1) and later, cognitive-emotional stages (LPP). While these effects may be seen as an index of the objectification and dehumanisation of the disabled, there was mixed evidence to support this from our measures of interpersonal disgust, empathy and attitudes. Observers who responded to bodies with missing limbs with reduced BIEs at P1-N1 and P2-P3, and with enhanced positivities at LPP, also reported more negative attitudes towards disabled persons. At the same time, observers who responded to bodies with missing limbs with reduced BIEs in behavioural measures also had higher trait empathy. We propose that both empathic concern and negative assumptions about disabled persons’ experiences and roles in society may lead to increased attention toward missing limbs in particular. This in turn reduces configural visual processing, and enhances the body part’s emotional salience.
13) Evidence of early gating of sensory information by alpha oscillations inferred from an iconic memory task
Roberto Cecere, Amalia Gomoiu, Stephanie Morand, Monika Harvey and Gregor Thut (University of Glasgow)
Amplitude fluctuations of brain oscillations at baseline have repeatedly been shown to affect the perceptual fate of incoming sensory stimuli. Particularly, pre-stimulus power in the alpha-band (8-14Hz) over occipito-parietal areas has been inversely related to perception, and is thought to reflect gating of sensory information [1-5]. However, despite a comprehensive body of work, there is little consensus on the processing stage at which alpha power affects perception. One prominent, yet untested interpretation is that alpha oscillations inhibit/gate the information flow at an initial, input stage into sensory cortices [6-9]. Alternatively, this influence comes later when information is read out from early sensory cortices to higher-order areas [2,10,11]. Here, we distinguish between these alternatives by investigating whether pre-stimulus alpha-power influences the initial availability versus information decay in an iconic memory task. Specifically, the availability of visual information was sampled at different times between 40 and 300ms after presentation of a multi-item visual display, while concurrently recording multichannel EEG in 27 participants. Logistic regression was then employed to link pre-stimulus oscillations to iconic memory performance across trials within participants, followed by cluster-based statistics across participants and single trial sorting of memory performance. Results revealed a pre-stimulus cluster in the alpha and beta bands over occipito-parietal areas that affected initial availability but not memory decay within participants. A similar, but non-significant trend was observed between participants. Our findings suggest that alpha power is linked to input-gating rather than iconic memory decay. This provides first time evidence for very early gating effects of alpha-band amplitude, complementing evidence for alpha-power influence on later processing stages [11]. Hence, alpha-oscillations seem to affect perception at several stages.
14) Is there anything special about death in the brain? A Frequency-tagging EEG study of death anxiety
Istvan Laszlo Gyimes and Elia Valentini (University of Essex)
Previous research showed that images possessing arousing content lead to changes in the emotional/affective states of the onlooker [1,2]. We combined this evidence with the notion that reminders of death activate an exclusive anxiety mechanism different from the one activated by other types of symbolic threats [3]. This notion is supported by evidence showing how experimental participants verbally reflecting on their own death are then influenced in their opinions and behaviours [3–7]. Here we built on previous research on affective pictures to address a question that has only recently attracted the attention of neuroscientists: Does information about death have a specific effect on brain activity? We tested the hypothesis that passive observation of visual death-related content would trigger greater synchronised brain activity recorded from parietal and occipital regions of the scalp when compared to threat-related content. To address this question we implemented the Fast Periodic Visual Stimulation (FPVS) with neutral images constituting the standard familiar events and the death or threat scenes being the oddball deviant event. In two experiments, we found that images depicting death content evoke lower frequency-tagged EEG response compared to more generic threat images. Visual evoked potentials revealed that a brief change of the scene from neutral to threat content elicits greater amplitude at the late latencies (compatible with a P300 potential), particularly at the parieto-occipital sites. Altogether, our findings suggest that passive observation of death cues does not trigger greater neural synchronisation than that elicited by similarly negative and arousing cues with divergent threatening meaning.
15) EEG correlates of implicit and explicit recognition memory for faces
Robin Hellerstedt, Matthew Plummer, Stuart Gibson, Jon Simons and Zara Bergström (University of Kent; University of Cambridge)
Recognition memory is not a single process, but rather involves contributions from different memory systems that may or may not elicit a subjective experience of recognition. Furthermore, subjective recognition experiences are not always based on objective memory, because people can experience highly confident false recognition, suggesting a dissociation between implicit/objective versus explicit/subjective recognition processes. These subprocesses of recognition memory are well characterised for verbal stimuli, but less is known about the different neurocognitive mechanisms that underlie recognition of human faces. It is also unclear whether implicit/objective and explicit/subjective memory mechanisms contribute to face recognition in a graded or all-or-none fashion. We combined EEG measures of brain activity with a continuous measure of face recognition to investigate these issues. Participants studied target faces before engaging in a sequential recognition test. In this test, each of the target faces were presented together with four similar distractor faces, and participants were instructed to select the target face and to rate their confidence in their decision. Face stimuli were created using a face space model algorithm that enabled us to vary the distractors’ similarity to the target on a continuous basis. We sorted EEG responses to faces into event-related potential (ERP) conditions based on distractor similarities to the target or the selected distractor face in case of errors, in order to investigate if ERP correlates of objective and subjective face recognition were elicited in a graded or all-or-none pattern. We also examined the extent to which these ERP correlates of face recognition varied as a function of decision confidence. The study provides a first step towards dissociating the neurocognitive mechanisms that contribute to face recognition.
16) How do we represent observed actions? Investigating the specificity of the sensorimotor encoding of human bodies using EEG
Sonia Abad-Hernando, Alejandro Galvez-Pol, Bettina Forster and Beatriz Calvo-Merino (City, University of London; University College London)
How do we represent observed actions in working memory? Could we differentiate between perceptual or functional roles of embodiment? Recent studies already suggest we hold information in working memory (WM) differently when it contains body information. It has been shown that visual encoding of body stimuli engages electrophysiological activity not only in visual cortices, but also in body-related areas. It was found that persistent activity increased in somatosensory cortex (SCx) only when maintaining body images in WM, whereas visual/posterior regions' activity increased significantly when maintaining non-body images [1]. The aim of this study is to clarify whether this activity is triggered by body stimuli per se, or modulated by the degree in which we embody that stimuli. For this purpose, participants performed a visual WM task [2] in which items to-be-remembered were coloured hand images (depicting 6 different hand positions and in 6 different colours). Each memory array consisted of 1 or 2 hands in each hemifield. In 50% of the trials, we elicited simultaneously VEPs and SEPs by applying task-irrelevant single tactile taps simultaneously delivered to both hands. This allowed us to do a later subtraction in order to isolate and examine the state of the somatosensory cortex (SCx) free of visually evoked activity, exposing its underlying processing during memory encoding and maintenance. We test if SCx areas involved in holding body information in memory are sensitive to the degree of embodiment elicited by different tasks while using the same body stimuli. This study will help us to dissociate the perceptual-functional roles on how working memory encodes body-related information.
17) Reduced semantic selection ability accounts for less coherent speech in old age
Paul Hoffman, Ekaterina Loginova and Asatta Russell (University of Edinburgh)
Semantic knowledge increases across the lifespan. However, the ability of older adults to regulate their access and use of this knowledge has not been investigated. We hypothesised that this ability would show age-related decline, in line with other forms of cognitive control. We also predicted that these declines could explain loss of coherence in older people’s speech, i.e., the increased tendency for older people to produce off-topic, tangential speech. 100 young and older people completed a battery of executive and semantic tests, including tests that probed controlled selection and use of semantic knowledge. 60 participants also provided speech samples elicited by a series of prompts (e.g., how do you look after a dog?). 15 older participants completed the speech elicitation task a second time during fMRI. Speech samples were transcribed and analysed using a novel computational technique that used latent semantic analysis to quantify the degree to which participants remained on-topic. Older people had greater reserves of semantic knowledge but also had specific impairments in semantic selection: they was less able to select the most relevant aspect of knowledge when multiple competing semantic representations were active. Poor semantic selection ability was associated with poor coherence in speech, explaining reduced coherence in the older group. During fMRI, highly coherent speech was associated with greater activation in the inferior prefrontal cortices (BA45), a region strongly linked with semantic selection processes. These data indicate that the status of semantic cognition in later life is more complex than previously assumed. While knowledge accumulates over the lifespan, selection of the most currently-relevant information becomes more difficult. Importantly, older people lose coherence when speaking because they find it hard to select the most relevant aspects of their knowledge to guide speech production.
18) Underlying mechanisms of reward-based motor learning
Peter Holland, Olivier Codol and Joseph Galea (University of Birmingham)
Motor learning - the ability to learn and update how action is performed - is a fundamental process which influences most aspects of our lives. Despite increasing interest in how reward enhances motor learning, the underlying mechanisms remain ill-defined. In particular, the contribution of explicit (conscious) processes to reward-based motor learning is unclear. To address this, we examined subject’s (n=30) ability to learn through reward-based feedback [1]. Subjects held a robotic handle and made reaching movements towards a visual target. The only feedback subjects received was a green tick on successfully hitting the target. Gradually the angle for a successful reach was rotated 25⁰ from the visual target. Only two-thirds of subjects (n=20) showed successful reward-based motor learning. The remaining subjects initially followed the rotation but subsequently began to reach at an insufficient angle and returned to near baseline performance (n=10). Importantly, those that were successful accomplished this largely via explicit processes, evidenced by a reduction in reach angle when asked to remove any strategy. Also, subjects who failed to learn showed decreased sensitivity to errors, a pattern previously found in Parkinsonian patients. In a second experiment, the addition of a secondary mental rotation task completely abolished learning (n=10) providing further evidence that successful reward-based motor learning is dependent on explicit mechanisms. In a follow-up experiment, we replicated the original results in a larger sample (n=120). Additionally, we measured performance on three memory tasks and collected genetic samples in order to examine the role short-term memory and the dopaminergic system in reward-based motor learning. Overall, these results emphasize a pivotal role of explicit processes during reward-based motor learning which has important implications for the efficacy of using reward-based motor learning in motor rehabilitation.
19) Physical exercise is as effective as transcranial direct current stimulation at enhancing long-term memory
Fadi Ifram, Daniel Osei and Amir-Homayoun Javadi (University of Kent)
It is well established that acute physical exercise is beneficial to declarative memory, especially when administered during consolidation. Also beneficial to declarative memory processes is the application of transcranial direct current stimulation (tDCS) over the dorsolateral prefrontal cortex (DLPFC) during encoding. In two studies we employed an old-new recognition paradigm, in which images were used to test the beneficial effects of acute physical exercise and tDCS on declarative memory. This study also tested the combined effect of tDCS and physical exercise on memory performance. In study 1, participants were assigned to the following conditions: physical exercise, anodal, and sham tDCS. In study 2, participants were assigned to the following conditions: physical exercise, physical exercise and anodal stimulation, and sham tDCS on memory performance. During anodal stimulation, participants received tDCS over the left DLPFC for 15 min. During physical exercise, participants were administered an exercise protocol on a cycle ergometer that kept their heart rate between 60-70% of their maximum heart-rate. The results of study 1 provide evidence that tDCS and physical exercise are able to significantly improve declarative memory, as indicated by increased memory performance scores on the old-new recognition task. The results of study 2 indicate that a combination of physical exercise and tDCS does not lead to further enhancements in memory performance over physical exercise when administered on its own. In conclusion, our results demonstrate that physical exercise is, at least, as good as tDCS at enhancing long-term memory performance.
20) The neuromodulatory effects of L-DOPA across human verbal memory processes
Hanna K. Isotalus, John P. Grogan, James Selwood, Nerea Irigoras Izagirre, Alex Howat, Lisa Knight, Risto A. Kauppinen and Elizabeth J. Coulthard (University of Bristol; North Bristol NHS Trust)
Long term memory can be divided into three core phases of processing; encoding, consolidating, and retrieving. In Parkinson’s disease verbal long term memory is improved with exogenous dopamine administration during consolidation and retrieval but impaired when dopamine is administered during encoding. Understanding dopamine’s roles across memory processes may have future implications in targeting therapeutics in amnesic disease. Here, we tested the effect of L-DOPA administration across verbal recognition memory processes in healthy ageing. In a placebo-controlled double-blind randomised crossover trial, 33 healthy elderly (65+ years) adults performed a verbal recognition memory task. Volunteers first learnt a word list on Day 1 without medication. On Day 2, to examine the effect of dopamine on retrieval, they were dosed with 150mg L-DOPA or placebo before their memory was tested. To target encoding, they then learnt a novel word list with memory tested immediately, and 1, 3, and 5 days later, with unique targets at each test. There was no difference in recognition accuracy between L-DOPA and placebo in either experiment and Bayesian analyses provided moderate support against L-DOPA affecting retrieval (BF₀₁=4.243) or encoding (BF₀₁=4.300). However, post-hoc analyses revealed that L-DOPA during encoding enhanced retrieval 3-days later for those with high trait depression or anxiety (r =.425 p=.030; r =.467, p =.016, respectively). Our findings suggest that exogenous dopamine does not enhance encoding or retrieval in healthy ageing, and that earlier results may be explained by dopamine boosting consolidation. Our ongoing placebo-controlled clinical trial investigates the efficacy of L-DOPA administration in targeting consolidation during sleep in healthy ageing but these data have not been unblinded.
21) Rhythmic encoding improves recognition memory
Alexander Jones and Emma Ward (Middlesex University, London)
There has recently been an increased interest in the way in which temporal expectancies shape perception and drive behaviour. Research has observed that intrinsic neural oscillations can entrain to external rhythms by aligning the firing pattern of neurons. Entraining neural oscillations has shown to enhance perception and facilitate behaviour for stimuli that appear in phase with the rhythm, yet relatively little is known about how temporal expectation during encoding influences subsequent memory. Participants in the present study were presented with a rapid succession of everyday objects in an encoding phase and asked in a subsequent recognition test phase to judge whether individually presented objects were presented before (old) or not (new). Importantly, the presentation of objects in the encoding phase followed a either rhythmic or arrhythmic temporal pattern, of which participants were not made aware. Recognition was significantly greater for items that were presented rhythmically compared to those that were presented arrhythmically. There was evidence of entrainment of neural oscillations with increased phase locking for rhythmically over arrhythmically presented stimuli during encoding. Moreover, memory specific ERP components at test phase were influenced by rhythmic encoding. Specifically, the FN400 old/new effect was present in both conditions, but a late positive component (LPC) old/new effect was only observed for rhythmically encoded items. This parietal old/new effect (LPC) has been proposed to be an index of recollection, specifically linked to memory for the contextual details associated with the encounter with the item. The study provides new evidence through EEG and behavioural measures that presenting stimuli in a rhythmic manner provides a benefit to recognition memory.
22) Native listeners’ intelligibility of vowel hyperarticulation and its relevance in speech learning in adults
Jayanthiny Kangatharan, Maria Uther and Fernand Gobet (Brunel University; University of Winchester; University of Liverpool)
Stretched vowel space is one acoustic-phonetic feature that has been reliably revealed to naturally be part of clear speech [e.g. 1, 2], and to correlate with speech intelligibility [3]. It was also found that those speakers, who can naturally articulate phonetic contrasts accurately on a segmental level and employ larger vowel space, are more intelligible than those with smaller vowel paces [4] To this date, only an association between vowel space expansion and speech intelligibility has been revealed. Nonetheless, because correlation does not necessarily imply causation, to this date, no study has directly tested whether speech with vowel expanded vowel space produced under naturalistic circumstances, and not merely by instructing speakers to speak as if they are talking to foreign listeners or hearing-impaired listeners are more intelligible than speech samples with non-expanded vowel space in a controlled setting. This study explored whether expanded vowel space, as elicited in speech to infants (IDS) leads listeners to perceive enhanced intelligibility. Twenty-one native speakers of English completed a transcription and confidence rating task, a goodness rating task and a clarity rating task to evaluate the intelligibility of hyperarticulated speech samples, which were directed by mothers to infants as compared to clear read speech samples produced by mothers. Statistical analysis showed higher transcription accuracy and clarity ratings for speech by mothers directed at infants versus clear read speech produced by mothers. Results suggest that speech with vowel hyperarticulation and other acoustic-phonetic features seems to enhance intelligibility to infants. The implications of the results are discussed with regard to current theories of speech communication and interaction.
23) Laterality effect of the illusory body space
Beatrix Zsidó Lábadi, András Norbert, Orsolya Inhóf, Eszter Kohn and Gergely Darnai (Univeristy of Pécs)
A growing body of research shows that right hemispheric networks support the illusory body space in the induction of the Rubber Hand Illusion (RHI) and subjects with a lower degree of lateralization and/or low interoceptive abilities are more susceptible to the bodily illusion [1]. However there is no information about how hemispheric lateralization and interoceptive ability relate to the body space network. In present study neurologically healthy adults have been studied using two experimental tasks measuring the body ownership for both hands with RHI and the pseudoneglect before and after the RHI induction with line bisection task. We also measured the degree of the laterality and interoceptive abilities. Our findings showed greater body ownership effect with greater proprioceptive drift and greater subjective feeling of ownership when the stimuli delivered on the left hand. Low interoceptive ability was associated with a stronger illusion with greater proprioceptive drift. The result of the line bisection task showed that the pseudoneglect was reduced only by RHI application to the left hand. In line with previous studies of functional hemispheric asymmetry for spatial processing, the left sided rubber hand has a greater access to the the right hemispheric network and shift subjective body midline to the right.
24) Mobile brain imaging identifies the re-allocation of attention during real-world activity
Simon Ladouce, David Donaldson, Paul Dudencko and Magdalena Ietswaart (University of Stirling)
Laboratory studies have long demonstrated that human attention has an inherently limited capacity. How limited attentional resources are distributed during real-world behaviour is currently unknown. Here we characterise the allocation of attention across multiple sensory-cognitive processing demands during naturalistic movement. We used a neural marker of attention, the Event Related Potential (ERP) P300 effect, to show that attention allocated to the detection of infrequent target stimuli is reduced when human participants walk down a familiar hallway compared to when they stand still. In a second experiment we show that this reduction in attention is not caused by the act of walking per se. A third experiment identified the independent processing demands driving reduced attention to target stimuli during motion. A significant reduction in attention occurred when isolating the capture of attention by inertial stimulation, and a larger reduction when isolating attentional capture by visual stimulation. Furthermore, the data reveal that the reduction in attention seen during walking reflects the linear and additive sum of the processing demands produced by visual and inertial stimulation. The mobile cognition approach used here shows how limited resources are precisely re-allocated across competing sensory modalities when attention is divided, demonstrating that attentional capture can be quantified during real world behaviour.
25) Temporal precision of predicting perceptual input from dynamic contexts in the early visual cortex
Yulia Y. Lazarova, Lucy S. Petro, Fabiana M. Caravalho, Angus T. Paton, Fraser W. Smith and Lars Muckli (University of Glasgow; University of Sao Paulo, Brazil; University of East Anglia)
The brain forms internal representations of the environment through repetitive exposure to spatiotemporal regularities in our surroundings. This allows the brain to proactively perceive sensory information by predicting upcoming perceptual input [1]. We investigated how predictions affect processing in the early visual cortex in the context of complex scenes. Using an event-related design we presented participants with short videos of naturalistic scenes and recorded brain activity from areas V1-V3 using 3T fMRI. Each video consisted of a priming sequence of images interrupted by a 800ms interval, followed by a single test frame. It came from one of four possible points of the video–an exact match of the resumed video after the gap, or taken from too late (4000ms) or too early (300, 600ms) point after the gap onset. The task was to mentally extrapolate the video and rate the test frame as matching, early, or delayed. In a control condition the images in the video were presented out of order, precluding the perception of coherent motion and hindering the formation of expectations about the test frame after the interval. To study the temporal dynamics of the occurring perceptual processes, we increased image exposure time from 100ms to 200ms. General linear model deconvolution analysis revealed lower BOLD response in V1 and V3v to the predictable matching test frame compared to the late mismatching one (4000ms). This signal attenuation was not seen in the control condition, where predicting upcoming input was impossible. Such activation drop in response to the coherent motion videos compared to the non-coherent ones was only seen in V1 when priming images were presented for 200ms but not for 100ms. We demonstrate that predictions about motion in complex scenes exist in the early visual cortex. They are temporally-specific and can extrapolate over time. It takes more than 100ms for predictive processes to take effect, suggesting recurrent processing in visual cortex.
26) Recruitment Issues with non-invasive brain stimulation in stroke patients
Gemma Learmonth, Keith Muir, Christopher Benwell, Matthew Walters and Monika Harvey (University of Glasgow; Queen Elizabeth University Hospital)
Up to 80% of people who experience a stroke that affects the right hemisphere suffer from hemispatial neglect. This syndrome is debilitating, impedes rehabilitation, and is a strong independent predictor of poor recovery. We carried out a pilot trial of transcranial direct current stimulation (tDCS) and a behavioural rehabilitation programme, alone or in combination, on 60 subacute patients with hemispatial neglect (>4 weeks post stroke). We randomly allocated patients to 10 sessions of 15 minutes each of 1 mA constant tDCS, 10 sessions of a "rod lifting" intervention, both interventions combined, or standard care (a control task). Our primary outcomes were recruitment and retention rates, with secondary outcomes measuring effect size and variance scores of neglect, activities of daily living and quality of life tests, assessed directly after the interventions and at 6 months follow up. Of 288 confirmed stroke cases referred (representing 7% of the screened population), we randomised only 8% (0.6% of stroke cases overall), with the largest number of exclusions (91/288 (34%)) due to medical comorbidities that prevented patients from undergoing 10 intervention sessions. We recruited 24 patients over 29 months, where 88% (21) of these completed testing and 67% (14) completed the 6 month follow up testing. We established poor feasibility for a larger trial, with a lower recruitment rate than envisaged (24 recruited out of 60 planned). A definitive hemispatial neglect trial using non-invasive brain stimulation, either with or without behavioural training, will require a broad recruitment base, and the intensity, duration and location of the interventions will have to be carefully selected.
27) Investigating neural correlates of embodiment through facial emotion perception, its relation to interoception and personality traits
V. Meletaki, B. Calvo-Merino, I. Arslanova and B. Forster (City, University of London)
Embodiment theories and studies have suggested that there is activation in somatosensory cortices at early stages of facial expression processing that might work independently from visual processing [1, 2]. Our study further investigates how different emotions modulate this early somatosensory activity and if this measurement of embodiment is related to interoception (i.e. interoceptive accuracy and awareness) or personality traits (i.e. depression, alexithymia). At the present study participants were shown photos of faces expressing happiness, anger, sadness and neutral, while measuring their electrophysiological activity. We measured their interoceptive abilities and their levels of depression and alexithymia (by means of Beck Depression Inventory and the Toronto Alexithymia Scale respectively). We calculated the visual evoked potential (VEP) and the somatosensory evoked potential (SEP) that was calculating by subtracting the visual only conditions from the tactile conditions. In accordance with the literature, results showed emotion modulation on the VEPs at P200. Regarding SEPs, we have a main effect of emotion on 100-120”, where significant differences in amplitude were found between the emotions happy, sad and angry and neutral. We further correlated the SEP amplitude of emotion with depression and alexithymia scores showing significant interactions between depression score and amplitude of sad emotion. These results provide novel evidence for distinct neural signatures for processing different emotions. The present study is of interest due to its innovative and interdisciplinary methodology as we combine the neural index of embodiment as proposed by Sel et al. [2] with psychometric and interoceptive measures.
28) When effort itself becomes rewarding: The interaction between task difficulty and reward contingency in the striatum
Stefanie Meliss, Michiko Sakaki, Kou Murayama, Madoka Matsumoto, Yukihito Yomogida, Kaosu Matsumori, Ayaka Sugiura and Kenji Matsumoto (University of Reading; University of Tokyo Hospital, Japan; National Center of Neurology and Psychiatry, Japan; Tamagawa University, Japan; Wayne State University, United States)
Many reward learning theories posit that effort is aversive, indicating that reward system would be least responsive to difficult and effortful options. However, research in psychology suggests that effort itself can be rewarding. To test this possibility, we examined the relationship between task difficulty and reward network with 51 healthy participants using functional magnetic resonance imaging. Participants were assigned to three groups: Control group participants did not receive any rewards (i.e. they worked on the task out of intrinsic motivation), whereas reward group participants received monetary rewards based on their performance. In the gambling group, task success or failure was probabilistically determined (not by the performance of participants). In all groups, participants worked on a game-like task that had three difficulty levels: easy, moderate, and difficult. The behavioural results showed that the effects of difficulty level on self-reported motivation differed between the groups, F(4,96) = 25.18, p < .001. In the control group, participants were more motivated with increasing task difficulty, whereas the gambling group showed the opposite pattern. Furthermore, the motivation ratings in the reward group followed an inverted U shape, exhibiting the highest motivation for a moderately difficult task. The neuroimaging analyses mirrored these findings: a bilateral cluster in the ventral striatum showed similar patterns of activation as observed in behavioural analysis (p < .05, family-wise error corrected). Exploratory functional connectivity analyses showed temporal correlation between activity in the striatal peak voxel and the lingual gyrus (p (uncorrected) < .001). Our results indicate that contrary to the current popular reward learning theories, effort has differential effects in the reward network depending on context and is not generally aversive.
29) Attentional capture by salient distractor in a tactile search task.
Carlos Mena-Poblete, Kadi Lang and Elena Gherri (University of Edinburgh)
Previous studies on tactile search have only used one target and homogenous distractors (fillers) (Forster, Tziraki, & Jones, 2015). Therefore, it remains unclear whether a distractor that shares a relevant feature will capture attention in a similar fashion to what has been observed in vision (Gaspar & McDonald, 2014; Hickey, McDonald, & Theeuwes, 2006). We used a task with 4 vibrotactile stimuli with different frequencies on 4 locations (2 fingers of 2 hands). Participants were asked to respond to the elevation of the target (top vs bottom fingers) while ignoring other simultaneous stimuli. There were 4 different conditions: target with three fillers (target only trials), distractor with three fillers (distractor only trials), target and distractor simultaneously the same hand (same side trials) or to the opposite hand (opposite sides trials) and two fillers. Results demonstrated that the distractor captured attention, resulting in slower RTs and lower accuracy on distractor present trials as compared to distractor absent trials. ERP analyses show the presence of the N140cc on target only and same side trials. Interestingly, there was a reliable N140cc also on distractor trials suggesting that the distractor was able to capture attention. In addition, the N140cc was reduced on opposite sides trials as compared to target only trials. This suggests that although participants were able on average to direct attention to the target, the presence of the distractor had detrimental effects on search performance.
30) ‘Is this your card?’ Group and individual analyses of EEG theta during a modified guilty knowledge task
Roger Moore, Amy Prior, Tom Lockhart and Thanusha V. Manohor (University of Portsmouth)
Lying is suggested to be cognitively demanding since it requires inhibition of the truth and generation of a new response. Increased cognitive load influences brain activity; therefore the distinction between lies and truths should be able to be differentiated by EEG. Increased EEG theta activation at frontal brain regions is proposed to be a result of increased task demands [1] so it is assumed that this may be reflected in differentiated EEG response during lying. Exploratory research was conducted into changes in EEG theta activity during initial reaction to guilty knowledge stimuli. EEG from 39 participants were recorded (14 electrodes) whilst participants underwent a modified version of the Guilty Knowledge Task [2], denying the identity of a concealed card, whilst also being shown control and irrelevant cards. Group: EEG analysis considering low (4-6Hz) and high theta (6-8Hz) power from aggregated data recorded across the midline from anterior - posterior cortical regions (yielding 5 virtual electrodes) revealed that power in both theta wavebands significantly reduced during lying relative to truth telling at all five of the virtual midline electrodes. Individual: The trend described in the group analyses differentiated lying from truth telling in 84.62% of the sample when low theta at the most anterior virtual electrode was considered, and 79.49% when low theta for the most posterior virtual electrode. When response at these two regions were considered together, discrimination accuracy rose to 94.87%. Whilst these data showed an unexpected trend (i.e. theta reduction when lying rather than increase) they strongly suggest that low theta EEG could potentially act as a useful tool in discriminating truthful from deceptive behaviour. The current study suffers from low ecological validity but this will be addressed in planned follow up work.
32) The role of neuromodulation on cognitive processing and enhancement in face perception
Montserrat Gonzalez Perez (University of East London)
Faces are important and among the most interesting stimuli on visual attention [1]; we rely on faces for social interactions. Face processing forms part of our everyday brain activity; it seems effortless the way we identify familiar and unfamiliar faces such as friends, family, celebrities or a complete stranger. Faces can also provide moods and emotions: eyes can provide gaze direction and lips can provide lip reading. All this compounded information concentrated in our faces can provide crucial information for us to behave appropriately in social interactions. When brain injury in the face processing network, the individual loses the ability to identify faces [2] ‘face blindness’. The aim of the current study was to use neuromodulation (techniques that directly affect the brain’s neurophysiology), specifically tACS, to causally demonstrate the functional relevance of GBO in face-processing. In addition, the category- and the process-specificity of tACS effects, as well as the role of the timing of neuromodulation with respect to the execution of cognitive tasks are still unknown. In this single-blind, sham-controlled study, was examined whether the administration of tACS over the right occipital cortex of healthy volunteers (N=48) enhances performance on perceptual and memory tasks involving both face and object stimuli. No study to date has investigated whether (tACS) can causally enhance face processing. Neuromodulation was delivered in three groups condition: Gamma 40 Hz, Theta 5 Hz and Sham. The results showed that tACS neuromodulation slightly enhances the perception and memory performance of both faces and objects. This study add relevant information about the cognitive processes and visual stimuli that can be modulated by tACS, and about the design of effective neuromodulation techniques and protocols, which have implications for advancing theories in cognitive neuroscience and possible clinical application.
32) ERP correlates for retrieval-induced updating of face memories
Matthew Plummer, Robin Hellerstedt, Stuart Gibson, Jon Simons and Zara Bergström (University of Kent; University of Cambridge)
Episodic memories are prone to updating, whereby errors made during recollection attempts can update the original memory [1,2]. Furthermore, ERP correlates of episodic memory updating are distinct from ERP markers of retrieval success [1,3]. However, it is not clear whether similar retrieval-induced updating mechanisms operate during item recognition, such as when we recognise faces. This issue was investigated in the present EEG experiment. We created face stimuli using a face space model algorithm [4] that enabled us to measure face recognition accuracy and updating on a continuous scale. Participants first learnt a number of face targets before an initial recognition test. Here, each trial presented a face target with distractor foil faces in a sequential recognition design, and participants were required to select the face target and report their confidence in their decision. This test was followed by a second test of identical design to the first. Behaviourally, high confidence responses from the first test were more likely to be repeated in the second test regardless of accuracy. This supports the notion that recognition errors made with high confidence were encoded into memory, thereby updating participants’ face memories. EEG analysis of the first test separated the ERP effects that were associated with retrieval success from the ERP effects that were predictive of updating, and investigated how these effects were modulated by confidence. The results show the neural processes engaged during face recognition that are associated with retrieval-induced distortions of face memories.
33) Electrical brain activity associated with false memory-related increases to subsequent recognition.
Louisa Salhi, Arianna Moccia, David Vogelsang and Zara Bergstrom (University of Kent; University of California, USA)
Incidental encoding takes place in many situations, including during old/new recognition tasks where new “foil” items are encoded to different extents depending on modulatory processes occurring during retrieval attempts [1]. Our recent findings suggest that one such modulator is false familiarity, since foil words that were falsely recognised as previously seen on a first test were subsequently more likely to be accurately recognised as previously seen on a final surprise test compared to other foil words that were correctly identified as new on the first test. This pattern may be due to false familiarity facilitating context encoding during the first test [2], or due to false familiarity “carrying over” across multiple tests (i.e. persistent false memories). In this EEG study, we investigated the neurocognitive mechanisms that underlie spontaneous false memory during an old/new task and how this relates to increased subsequent recognition. Source judgments during the subsequent old/new task also enabled us to examine if the false memories enhanced test context encoding or simply persisted without enhancing encoding. Initial behavioural findings replicate prior results by showing increased subsequent recognition for items that produced false familiarity on the first test. Source judgments indicated that this was mostly due to persistent false memories rather than familiarity facilitating encoding. EEG findings will provide more information on the neural mechanisms driving this effect, and how they relate to well-established markers of familiarity and recollection [3]. The results will also be used to inform the theoretical debate regarding whether there are dissociable novelty and familiarity processes during recognition tasks [4].
34) Assessing and adjusting for publication bias in the relationship between anxiety and the error-related negativity
Blair Saunders and Michael Inzlicht (University of Dundee; University of Toronto, Canada)
Many clinical neuroscience investigations have suggested that trait anxiety is associated with increased neural reactivity to mistakes in the form of an event-related potential called the error-related negativity (ERN). Two recent meta-analyses indicated that the anxiety-ERN association was of a small-to-medium effect size (rs =.-25 and -.28), however, these prior investigations did not quantitatively adjust these effect sizes for publication bias. Here, in an updated meta-analysis (k=58, N=3819), we found support for an uncorrected effect size of r =-.193, and applied a range of methods to test for and correct publication bias (trim-and-fill, PET, PEESE, Peters’ test, three-parameter selection model). The majority of bias-correction methods suggested that the correlation between anxiety and the ERN is non-zero, but smaller than the uncorrected effect size (average adjusted effect size: r =-.118, range: r =.-045 to -.179). Moderation analyses also revealed more robust effects for clinical anxiety and anxious samples characterised by worry, whereas mixed anxiety was not associated with the amplitude of the ERN. Our results suggest that future research exploring the anxiety-ERN relationship would benefit from increased statistical power and the adoption of certain open science practices.
36) Individual peak alpha frequency in touch – cognitive and methodological implications
Jonathan Silas and Alexander Jones (Middlesex University, London)
Oscillations in the alpha frequency range (8-12Hz), measured using electroencephalography (EEG), have been shown to have a functional role in cognition and attention in particular. For example, voluntarily shifting covert attention to one side of space leads to a decrease of alpha activity over the contralateral hemisphere. More recently, interest has turned to the notion that across individuals there is notable variance in the peak of the frequency, and these peaks are dependent on task demands or the participant’s “state”. Here we directly contrast four separate tasks commonly known to modulate alpha power, in a within subjects design. Using a somatosensory cue, participants (N=21) either oriented (1) endogenous or (2) exogenous attention to the right or left hand and response times were measured. In a passive task (3) participants received tactile stimuli at regular intervals to one hand only, akin to studies determining peak alpha desynchronization for subsequent brain stimulation. Finally, EEG was measured from participants whilst at rest (4) when no stimuli were presented. Results show a difference in lateralized alpha power depending on the task. Interestingly, we also observe differences in peak frequencies across tasks within the same individual. These findings have key implications in terms of understanding the functional role of alpha oscillations and how they vary across different states and individuals. Furthermore, recent advances in transcranial alternating current stimulation (tACS) have relied on ‘individualising’ EEG frequencies for subsequent stimulation. We suggest, that such frequency ‘individualisation’ or ‘localisation’ for the purposes of tACS, requires task-specific functional localisation.
36) The effects of reward on sequential reaching movements
Sebastian Sporn and Joseph M. Galea (University of Birmingham)
The expectation of receiving reward has been shown to improve the speed and accuracy of eye movements and simple reaching tasks [1,2]. Capitalising on the speed-accuracy trade-off and its implications for human and animal behaviour, these studies demonstrate that reward expectancy produces similar shifts in the trade-off curve as motor skill training [3,4]. This effect of reward to energise movements and actions has been described as motivational vigour [5] and could be of beneficial use in rehabilitation. However, it remained an open whether reward expectancy can also invigorate more complex sequential movements. We addressed this question using a novel paradigm which consisted of participants making sequential reaching movements to 4 targets arrayed as a novel shape. Each participant was exposed to a rewarded and non-rewarded shape. Rewarded shapes were cued with two stimuli (auditory and visual) and monetary reward was calculated based on movement speed using a closed-loop design. Importantly, if any of the targets were missed then a trial was deemed a failure. Hence, to receive reward participants had to maintain accuracy whilst improving movement speed. Experiment 1 showed a significant effect of reward expectancy on movement time (MT), which increased over the course of the training block (p < 0.0001 for early vs late performance in training). By the end of training (150 trials), the rewarded shape was being performed ~300ms faster than the non-rewarded shape whilst maintaining a similar level of accuracy. Experiment 2 replicated these findings (p < 0.0001) and in addition found a consolidation effect 24 hours later (p = 0.0001 for late training NS vs day 2 performance). Taken together, our findings demonstrate that complex sequential actions can be invigorated when paired with reward.
37) Neuroimaging to identify the underlying mechanisms of human 3D depth perception
Makoto Uji, Ines Jentzsch, Angelika Lingnau, James Redburn, Ian Cavin and Dhanraj Vishwanath (University of St Andrews; Royal Holloway University of London; NHS Tayside)
Viewing a real scene or stereoscopic image with both eyes can yield a vivid qualitative impression of tangibility and real separation in depth called stereopsis. This impression is conventionally thought to be by-product of binocular disparity processing. However, a similar qualitative impression can also be induced under monocular viewing of single pictures through an aperture. Previous neuroimaging studies focused primarily on identifying neural mechanisms for deriving depth from disparity. There has been little research examining the subjective impression of stereopsis. We conducted two experiments: (1) fMRI and (2) EEG study to identify the neural substrates of the subjective impression of stereopsis. In Experiment 1, 7 participants viewed scrambled or intact images of natural 3D scenes under three different viewing conditions [Binocular (pictorial), Monocular aperture (pictorial), Stereoscopic (colour anaglyph)] while performing a control visual attentional task. Fixed-effects GLM contrasts isolating stereopsis demonstrated a selective recruitment of posterior parietal regions, but not ventral or occipital regions for both monocular and binocular stereopsis. In Experiment 2, 12 participants viewed 2D and 3D pictorial images under four different viewing conditions [Binocular, Monocular, Binocular aperture, Monocular aperture] while performing a control visual attention task. We localized EEG oscillatory sources (beamformer techniques), and conducted time-frequency analysis to examine power change in alpha (8-13Hz) and gamma (55-80Hz) frequency. Differential gamma synchronization was observed within the parietal cortex for the contrast isolating monocular stereopsis. Together, these initial studies suggest that neural activity in posterior parietal cortex might underlie the qualitative impression of stereopsis.
38) The role of hippocampal volume and the action of co-beneldopa on consolidation of associative memory in healthy elderly
Rachel L. Williams, Hanna Kristiina Isotalus, John P. Grogan, Michael J. Knight, Risto A. Kauppinen and Elizabeth J. Coulthard (University of Bristol; North Bristol NHS Trust)
Healthy aging and several age-related amnesic diseases have negative impacts on memory consolidation and the hippocampus (HC). Dopamine (DA) is a neuromodulator of the HC and increasing DA levels may enhance memory consolidation. The aim of this study was to investigate the relationship between DA, associative memory and the HC. We hypothesised that DA medication improves consolidation of paired associates (PA), compared to placebo, and that larger HC subfield volumes, as measured by MRI, are associated with better associative memory. In this double-blind placebo-controlled randomised clinical trial, 30 healthy elderly adults learnt 48 paired images on a computer screen. Participants were instructed to remember which pictures were shown together. After learning, either co-beneldopa (CR 50/200mg) or placebo was administered. Early recall of 24 pairs was tested 1h after learning and late recall of all items was tested the following morning (~12h). Each volunteer underwent both drug conditions. The HC and its subfields were imaged on a 3T MRI scanner using an in-house developed CPMG-like sequence and segmented using the automated ASHS procedure. We have currently unblinded 5 participants with a further 25 enrolled. Our results so far have confirmed the feasibility of this study with drugs being well tolerated and successful segmentation of HC subfield volumes. Preliminary results (n=5) show mean (±SDs) accuracy for PA image pairings at late recall was 95% (±11%) in the placebo and 83% (±24%) in the DA condition. Mean (±SD) left and right HC subfield volumes were 1181.93mm3 (±181.25) for cornu ammonis (CA) 1, 17.53mm3 (±5.97) for CA2, 65.94mm3 (±26.58) for CA3, 735.00mm3 (±76.75) for dentate gyrus, 354.16mm3 for subiculum (±56.31) and 5122.16mm3 (±753.76) for total HC volume. We now proceed to collect data from 30 participants to investigate the potential use of overnight co-beneldopa for improving associative memory.
39) Inner speech during silent reading of direct quotations is linked to theta-band neural oscillations
Bo Yao, Briony Banks, Jason Taylor and Sonja Kotz (University of Manchester; Lancaster University; Maastricht University, Netherlands)
Embodied cognition theories propose that language processing may rely on the same modal systems for perception and action [1]. Speech perception relies on theta-band (4-7Hz) neural oscillations for segmenting and coding continuous speech signals into hierarchical linguistic units for comprehension [2,3]. Does this theta-band oscillatory mechanism also govern mental simulation of speech (inner speech) during silent reading of direct quotations? In an EEG experiment, thirty-two native speakers of English silently read 120 short stories that contained either a direct speech (e.g., Mary said: “This dress is lovely”) or an indirect speech (e.g., Mary said that the dress was lovely) for comprehension. Their EEG data were pre-processed and epoched to the onsets of the speech quotations, followed by time-frequency decomposition. In the theta frequency band (4-7 Hz), we observed significantly higher phase-locking value (i.e. inter-trial phase coherence) in the right temporal sensors at ~200-400ms when reading direct (relative to indirect) speech quotations. This reflects a phase reset at the start of inner speech processing, similar to that at the onset of speech perception [4,5]. The phase reset was source-localised to the right posterior superior temporal sulcus – areas that are linked to prosodic processing of speech in perception [6]. In line with the embodied cognition framework, our results demonstrate that mental simulation of speech may engage the same theta-band oscillatory mechanism for perception of actual speech.
40) Visual tone facilitates the early auditory tone processing: Evidence from N1 and P2
Rui Wang, Xun He and Biao Zeng (Bournemouth University; University of South Wales)
Salient visual feature facilitates to predict the corresponding auditory speech signal, hence leading to a greater audiovisual (AV) reduction effect in N1/P2 latency (van Wanssenhove, Grant & Poeppel, 2005). The current study investigated whether such AV reduction occurred to Mandarin lexical tone. For lexical tones, the visual feature is less salient than the one in consonants, e.g. mouth shape or lip movement. Based on this, the AV reduction effect should be smaller in lexical tone response compared the one in consonant response. Same-different discrimination paradigm was used in the study. Participates were asked to judge whether two sequential stimuli were same or different for their auditory information. The two sequential stimuli were played in three conditions; 1) auditory-only and audio-only; 2) auditory-only and audiovisual; 3) auditory-only and visual-only. Twenty participants (aged 25.75 ± 4.4 years; female: 13) participated in the lexical tone experiment, and 19 participants (aged: 26.58 ± 5.69 years; female: 11) took part in the consonant experiment. The results showed a few major electrophysiological features of AV lexical tone integration. First, the auditory processing of lexical tones was suppressed and was accelerated by visual tone input starting from the auditory N1 time range, which further supports the AV benefit effect on lexical tones. Second, AV lexical tone integration maximised later than AV consonant integration and lasted longer (over N1 to P2). Third, lexical tone interaction processing showed more right-lateralised activation.
41) Primacy of mouth than eyes to perceive audiovisual mandarin lexical tones
Biao Zeng, Guoxing Yu and Nabil Hasshim (University of South Wales; University of Bristol; Bourenmouth University)
This study investigated Chinese and English speaker’s patterns of eye movement when they were asked to identify audiovisual Mandarin lexical tones. The Chinese and English speakers were presented a clip of Mandarin monosyllable (/ă/, /à/, /ĭ/, /ì/) in audiovisual mode and asked to identify whether the syllable was a dipping tone (/ă/, / ĭ/) or a falling tone (/ à/, /ì/). These audiovisual syllables were presented in clear, noisy and silent conditions. An eye-tracker recorded the participants’ eye movement. It was found that the participants gazed more at mouth than eyes and the mouth took more than 40% gaze duration at average. In addition, when the auditory information descended through three acoustic conditions, both Chinese and English speakers increased the gaze duration at mouth rather than eyes. The findings suggest, for audiovisual lexical tone, mouth is the primary area, not eyes. The similar eye movement patterns between Chinese and English speakers implies that mouth might play a perceptual cue relevant to articulatory than semantic information.
42) Impaired visual-object recognition in people with dyslexia: An ERP study of perceptual closure
Janusz Zielinski, Angela Gosling, Elley Wakui and Mary-Jane Budd (University of East London)
Developmental Dyslexia is a language disorder which manifests itself in the inability to learn to read adequately when IQ and vision are normal. Problems in reading and writing and phonological processing shown by Developmental Dyslexics may lie in poor visual coding from a deficit in the visual dorsal stream [1]. One approach to studying visual processing is object recognition and perceptual closure. This refers to filling in missing information by the visual system to presented images. Images were presented using different spatial frequencies from a blurred image to a clear image and were presented successively (less blurred until recognized). An Event Related Potential (ERP) called the closure negativity Ncl can be measured with each successive presentation of the image. The Ncl increases until the image is recognised and then the Ncl becomes stable. The Ncl of Dyslexics and non-dyslexics were compared, along with the preceeding P1 component, an indicator of dorsal stream neural activity, and the N1, an indicator of ventral stream processing. Differences were found in both the Ncl and the P1, with a qualitative difference between the two groups showing in the Ncl indicating perhaps different neural generators whereas, the P1 showed a more enhanced amplitude for the non-dyslexics (a quantitative difference). These differences in the visual processing of objects in dyslexics are discussed with how this may disrupt the visual input required for reading
43) Alterations of cortical thickness and global myelin over the primary sensory cortices
in a sample at ultra-high risk for psychosis
Aikaterini Zikidi, Alessio Fracasso and Peter J. Uhlhaas (Carl von Ossietzky University of Oldenburg; University of Glasgow)
Previous research reported a loss of cortical thickness throughout cortical and subcortical areas in schizophrenia (Scz). One of the most prominent findings is the disproportionate supra-granular thinning in comparison to the infragranular compartments [1,2]. One functional consequence could be an impairment in feed-forward processing due to the role of superficial layers in the propagation of incoming sensory information [3,4]. First findings by Wagstyl and his colleagues [5] have highlighted a steeper thinning gradient along the sensory hierarchies in Scz- patients, especially in visual areas. However, it is currently unclear whether such abnormalities exist at illness-onset. Methods: To address this issue, we recruited 202 participants, in 4 groups: ultra-high risk (UHR) for psychosis (n =105), first episode (FEP) psychosis (n = 13), substance abuse and affective disorders (n = 34) and healthy controls (n = 50 ). Participants were characterized through neuropsychological and psychiatric assessments. High resolution T1 scans were acquired and analysed in terms of (a) GM density over the whole cortex, (b) myelination density over the primary sensory cortices and (c) differences in myelination levels across cortical depth. Results: Pronounced cortical thinning was observed in sensory areas in FEP- and UHR- groups compared to controls, specifically in auditory and visual cortices. Moreover, we detected a coupling between thinning and lower myelination levels (measured via T1-w intensity) along the sensory hierarchies. Discussion: Acquiring further insights into myelin-related neuroanatomical changes that are traceable through MRi scans, will enable us to unveil anatomical links between the emerging deficits of cognitive and sensory processes in schizophrenia and alterations over the sensory hierarchies that are present prior to the full manifestation of the disorder.
44) Functional network correlates of lack of control and impulsivity in healthy young adults
Andras N. Zsido, Szabolcs Bandi, Orsolya Inhof, Beatrix Labadi, Nikolett Arato, Timea Budai, Gabor Perlaki, Gergely Orsi, Norbert Kovacs, Tamas Doczi, Jozsef Janszky and Gergely Darnai (University of Pécs, Hungary)
Understanding which brain regions engaged in response inhibition and impulsivity control provides insight into the underlying mechanisms of behavioural addictions. Research on internet addiction, in particular, draws more and more attention due to the novelty of the field and the growing prevalence. Furthermore, due to a hiatus in clinical practice to help the recovery of those suffering in internet addiction. We used the Stroop-task and a nonverbal Stroop-like task to assess inhibitory ability, while measuring task-related fMRI responses in 60 young adults. The Motor Impulsivity subscale of the Barratt Impulsiveness Scale and the Control disorder subscale of the Problematic Internet Use Questionnaire was used to measure impaired control functions and impulsivity. We reduced the dimensionality of the fMRI data set using independent component analysis, and then examined correlations between questionnaires and the resulting component scores. The analyses yielded 36 independent components. We excluded 14 based on visual checking. The remaining 22 components were correlated with the two questionnaires separately. Three components (5, 7, 9) correlated significantly with both questionnaires after controlling for multiple comparisons. Component 5 included key regions associated with response inhibition, including the Supplementary Moor Area, Superior Frontal Gyrus, paracingulate, insular cortex; and regions associated with the default mode network, such as praecuneus, postcentral and medial frontal gyrus. Component 7 included similar areas without the SMA, but also precentral gyrus and opercular and frontal orbital cortices. Component 9 was again similar to Component 5 but including the pre- and postcentral gyri. The relationships between brain activation and questionnaire scores suggest multiple possible mechanism on how excessive internet use may influence brain functions.
Chengetai Charidza and Helge Gillmeister (University of Essex)
The ability to simulate the motor properties of emotional body language has been largely associated with empathy and the observation-execution matching properties of the mirror neuron system (MNS). A purported index of MNS activity is the mu rhythm, which is comprised of sensorimotor alpha and beta oscillations. This study investigated whether event-related desynchronisation (ERD) of mu alpha (7.5 – 12.5 Hz) and mu beta (12.5 – 30 Hz) would differentiate between different emotional facial expressions. Participants watched videos showing face models act out the six basic emotions (anger, disgust, fear, happiness, sadness and surprise). Mu alpha distinguished between anger, disgust and fear, with greater ERD for disgust than for anger or fear over frontal midline electrodes. Mu beta distinguished between happiness and sadness, with greater ERD for happiness than sadness over superior parietal electrodes. These findings suggest that sensorimotor simulation, as indexed by mu, is more sensitive to certain emotional stimuli and may play a role in emotion recognition. In a follow up study, we further investigated whether mu oscillatory indices of emotional processing would differ in high trait anxiety individuals, as such individuals show cognitive and neural biases toward negative emotional stimuli in particular.
2) Evidence of loss aversion during effort-based decision-making
Xiuli Chen, Henry Marks, Lilian Berenyi and Joseph M.Galea (University of Birmingham)
Due to the prevalence of disorders that show a diminished willingness to exert effort (e.g. depression, Parkinson’s disease, stroke), there is increasing interest on effort-based decision-making in which humans evaluate the trade-off between benefits and motor costs. It is unknown whether loss aversion (tendency to prefer avoiding losses to acquiring equivalent gains) is apparent during effort-based decision-making. On the one hand, as distinct brain regions appear to subserve choices based on effort and value, similar dichotomies between reward and punishment may not exist. On the other hand, loss aversion is hardwired due to asymmetric evolutionary pressure on losses and gains, and thus may exist during effort-based decision-making. To examine this, participants (N=24) were asked to make a series of choices about whether to produce a required force to either gain or to avoid losing points. The amount of force required on each trial varied (one of 15%, 25%, 35%, 45%, 55%,65% of maximal voluntary effort). The amount of points offered was based on adaptive procedures given their previous choices. As expected, participants demanded more points for increasing physical effort in both conditions. Interestingly, only at the higher force levels (45%-65%), participants demanded higher points in reward than punishment condition to engage in the same force level (loss aversion). In addition, the time to decide between options was longer when rejecting a force option (forgoing rewards or accepting punishments) than when accepting a force option (gaining rewards, avoiding punishments). Crucially, this difference was greater in the punishment condition, suggesting a greater sensitivity to loss. These results indicate that loss aversion is clearly evident during effort-based decision-making, which coult have important implications for developing novel interventions to overcome the diminished willingness to exert effort in a range of clinical disorders.
- Kurniawan, IT, Guitart-Masip, M; Dayan, P, Dolan, RJ, (2013) Effort and Valuation in the Brain: The Effects of Anticipation and Execution. Journal of Neuroscience , 33 (14) pp. 6160-6169. 10.1523/JNEUROSCI.4777-12.2013.
- Kahneman, D., & Tversky, A. (1984). Choices, values, and frames. American Psychologist, 39(4), 341-350. http://dx.doi.org/10.1037/0003-066X.39.4.341
3) Concomitant but dissociable effect of reward on selection and execution components of motor control
Olivier Codol, Peter J. Holland and Joseph M. Galea (University of Birmingham)
When performing a movement, performance usually depends on whether the optimal action was selected and if that action is executed properly. Both of these components can show improvements during learning, and usually rely on overlapping but distinct anatomical circuits in the brain. Much evidence now shows that reward promotes learning in action selection [1,2], while it increases vigour in the execution component of a movement [3]. While these effects have been well documented, no study managed to dissociate the effect of reward on action selection and execution during the same motor task (4). Specifically, we addressed here whether any, or both these components benefit from the introduction of performance-based monetary reward. The task consisted of reaching to a target as fast as possible, with faster reaction times and movement times being rewarded with 0 to 50p per trials proportionally to performance. Distracting targets were occasionally introduced to induce a selection component to the task. First, a strong increase in movement peak velocity was observed in rewarded trials as opposed to non-rewarded trials, despite similar radial errors to target. However, this led to an asymmetric shift in the speed-accuracy function, with only very fast movements displaying reward-induced effects. On the other hand, while selection speed (reaction times) remained the same across reward magnitudes, selection accuracy (proportion of distracted trials) drastically improved in rewarded trials compared to 0p trials, regardless of reward magnitude. This also translated in a clear shift in the selection speed-accuracy function across the whole range of reaction times expressed. These results suggest that our task successfully isolates selection and execution components in motor control and that reward plays a strong, but dissociable role in each of these components.
- Gurney, K., Prescott, T. J., & Redgrave, P. (2001). A computational model of action selection in the basal ganglia. I. A new functional anatomy. Biological Cybernetics, 84(6), 401–410.
- Wachter, T., Lungu, O. V., Liu, T., Willingham, D. T., & Ashe, J. (2009). Differential Effect of Reward and Punishment on Procedural Learning. Journal of Neuroscience, 29(2), 436–443. https://doi.org/10.1523/JNEUROSCI.4132-08.2009
- Chen, X., Holland, P., & Galea, J. M. (2018). The effects of reward and punishment on motor skill learning. Current Opinion in Behavioral Sciences, 20, 83–88. https://doi.org/10.1016/j.cobeha.2017.11.011
- Dudman, J. T., & Krakauer, J. W. (2016). The basal ganglia: from motor commands to the control of vigor. Current Opinion in Neurobiology, 37, 158–166. https://doi.org/10.1016/j.conb.2016.02.005
4) Pre-stimulus EEG alpha power and its relation with subjective perceptual awareness
Andra Coldea, Christopher S.Y. Benwell, Monika Harvey and Gregor Thut (University of Glasgow)
The state of neural excitability at the time of presenting a sensory stimulus strongly influences its perception. Previous studies have shown that the power of ongoing oscillatory alpha band activity predicts whether an upcoming weak visual stimulus will be detected or not. It is unclear how baseline oscillatory activity modulates performance, but it has been recently suggested that alpha power modulates changes in detection criterion (i.e. low alpha power causes an increase in the tendency to report a stimulus regardless of its presence) and not in visual sensitivity as previously thought. We recorded EEG whilst participants performed a single visual stimulus identification task in combination with single-trial ratings of perceptual awareness. The aim of the present study was to assess whether the power and frequency of pre-stimulus oscillatory activity is related to objective performance (i.e. discrimination accuracy) and/or subjective perceptual awareness on a trial-by-trial basis. In addition, this relationship has been investigated using psychophysical testing based on Bundesen’s Theory of Visual Attention (TVA; Bundesen, 1990). Pre-stimulus power centred in the alpha band (8-14 Hz) was inversely related to perceptual awareness ratings, but did not predict discrimination accuracy. In addition, no significant relationships were found between EEG power and the TVA parameters of interest. Altogether, these results provide evidence that pre-stimulus alpha power is closely linked to ratings of subjective perceptual awareness, but does not influence the visual sensitivity when a decision is made about a stimulus feature. Thus, a clear dissociation between has been found between the influence of ongoing oscillatory alpha band activity on perceptual awareness and objective performance.
- Bundesen, C. (1990). A theory of visual attention. Psychological Review, 97(4), 523.
5) How does the form of feedback influence the way we process the message?
Chelsea Dainton, Bertram Opitz and Naomi Winstone (University of Surrey)
Within education, both Evaluative Feedback (EF; how you have performed) and Directive Feedback (DF; how to improve in future) are used to promote learning. A recent study by Nash et al. (in press) has shown that DF, though more often requested by students, is often forgotten or misremembered in a recall task compared to EF. This study investigated whether differences in the ease of decoding (with EF being easier to decode) and utility (with DF providing more utility) of feedback could explain this paradox. Electroencephalogram (EEG) measures were utilised by the researchers to understand whether underlying brain processes can explain this difference in behaviour. The feedback related negativity (FRN) signal is an event related potential that is used to measure feedback processing. However, no study has yet measured DF using these measures. Thus, the current study aimed to investigate whether DF produced an FRN signal similar to that of EF, and whether this component is sensitive to the ease of decoding or utility of feedback provided. Behavioural results highlighted confirmed the importance of both factors on performance. Feedback that was easy to decode and easy to utilise produced the highest accuracy and fastest reaction times, whilst the easy to decode but hard to utilise feedback produced the lowest accuracy and slowest reaction time. Within the EEG data a signal similar to the FRN was found in DF which exhibited sensitivity to ease of decoding and utility of feedback. Explanations for these findings and suggestions for future research are discussed.
- Nash, R. A., Winstone, N. E., Gregory, S. E., & Papps, E. (in press). A memory advantage for past-oriented over future oriented performance feedback. Journal of Experimental Psychology: Learning, Memory, and Cognition.
6) Impaired language networks in Internet addiction: Verbal fluency task-related fMRI study
Gergely Darnai, Gabor Perlaki, Gergely Orsi, Andras Zsido, Orsolya Inhof, Beatrix Labadi, Szabolcs Ajtony Bandi, Nikolett Arato, Timea Budai and Jozsef Janszky (University of Pecs, Hungary; Pecs Diagnostic Centre, Hungary; Szentagothai Research Center, Hungary)
Internet addiction is becoming an important mental issue. Earlier studies revealed that the excessive use of Internet can lead to increased loneliness, reduced communication and social skills, decreased intra-familial participation, depression, and poorer mental health [1,2]. However, the exact brain-related mechanisms behind these phenomena are still unclear. Since we claim that impaired language processing might be the primary reason, our aim was to study if alterations in language networks are related to Internet addiction. Methods. Sixty healthy, young, right-handed healthy university students were included. They underwent a block-designed phonological verbal fluency task during BOLD-contrast imaging in 3T Siemens MRI scanner and completed the Problematic Internet Use Questionnaire [3]. Three subscale scores (Neglect, Control, and Obsession) and Total score were calculated. Task-related activations were assessed using model free (T-PICA) and model-based (GLM) analyses. Results. We found two components (C3 and C4) that were related to Control subscale and Total scores. C3 contains areas that play important role in language processing including the left inferior frontal gyrus (pars opercularis), left supramarginal gyrus, left precentral gyrus and left middle frontal gyrus. According to the GLM analysis, Control subscale was related to activations in the left pre- and postcentral gyri. Conclusions. According to our results, Internet addiction is related to altered language network and this relationship might explain some comorbid symptoms related to Internet addiction.
- Engelberg, E., & Sjöberg, L. (2004). Internet use, social skills, and adjustment. CyberPsychology & Behavior, 7(1), 41-47.
- Soleymani, A., & Farahati, M. (2014). The impact of excessive internet use on communication skills and mental health in cafe Internet users. International Journal of School Health, 1(2).
- Demetrovics, Z., Szeredi, B., & Rózsa, S. (2008). The three-factor model of Internet addiction: The development of the Problematic Internet Use Questionnaire. Behavior Research Methods, 40(2), 563-574.
7) Cross-modal contextual effects from vision to touch
Cristina Denk-Florea, Andrew T. Morgan, Lucy S. Petro and Lars Muckli (University of Glasgow)
Activity in early somatosensory cortex (S1) is influenced by other sensory systems. Although this phenomenon was explained in the context of cross-modal contextual effects, the majority of evidence is speculative. In this fMRI study we investigated using multivariate pattern analyses whether joint multi-sensory experience (visual-haptic) with novel objects from two categories will lead to the decoding of the objects in S1 during unimodal visual presentation of images of the objects. In this study we were also interested to observe if cross-modal contextual effects in S1 extend to familiar natural scene images. According to the neural representation of perceptual experience theory we anticipated the objects and scenes to be decoded in S1. The participants (N= 10) were split in two groups, only one of the groups having visual-haptic experience with the objects. In the MRI scanner all participants viewed identical images. We discovered that we could only decode between two object pairs in the group who had visual-haptic experience with the objects and one pair of objects in the group who had no visual-haptic experience with the objects. However, our results indicate a trend, the decoding of the objects being generally higher in the group of participants who had visual-haptic experience with the objects. We discuss our findings in the context of stimuli limitations in inducing tactile predictions, the study being underpowered, as well as unaccounted mechanisms which might have influenced the results. Our results contribute to gaining a better understanding of multi-sensory processing and joint multi-sensory experience in modulating the activity in S1.
8) The influence of top down contextual predictions on the processing of degraded feedforward information
Gemma Donnelly, Johanna Bergmann, Matthew Bennett, Lucy Petro and Lars Muckli (University of Glasgow)
The brain uses contextual information to form predictions about input. When input is weak or ambiguous, context can aid processing. Previously, we investigated activity in early visual cortex while processing partially occluded images. Activation patterns revealed top-down predictions are sent to V1. Here we investigate how contextual information facilitates detection and recognition of visual input. With a behavioural experiment, we investigated how top-down predictions influence the processing of low-contrast input. Instead of occluding a region entirely, low contrast stimuli shone through the occlusion – like viewing behind a frosted screen. In expt-1, the lower right quadrant, our target region, of a scene, was shown at 8 low contrast levels. The surrounding full-contrast quadrants were either consistent with the target region, inconsistent or absent. Subjects identified whether the target contained a scene (detection task) and whether this scene was natural or man-made (identification task). Results show that when surround and target regions are consistent identification accuracies are higher than when the surround is absent. When the target and surround are inconsistent, accuracies drop to below chance, indicating an interference from top-down predictions. Detection does not differ with different surround input. To further test this contextual effect we conducted expt-2 using 7 contrast levels around the perceptual threshold. Again, detection rates remain stable across conditions but identification accuracies differ, indicating that consistent information is recognised easier than inconsistent. This suggests contextual predictions influence identification but not detection of stimuli. Our results show top-down predictions facilitate the processing of weak feedforward information consistent with these predictions and interfere with that of inconsistent input and are in line with the notion of neuronal sharpening of representations of predicted stimuli.
9) Investigating embodied representations of emotional expressions in ASD: A study with SEPs
Martina Fanghella, Beatriz Calvo Merino, Sebastian Gaigg, Matteo Candidi, Salvatore Maria Aglioti (Sapienza, University of Rome, Italy; City, University of London)
Autism Spectrum Disorder (ASD) is a neurodevelopmental condition characterised by difficulties in social interaction and communication, as well as repetitive and restricted patterns of behaviour and interests (American Psychiatric Association, 2000). Recent research suggests that differences in embodied representations of emotional expressions might play a role in ASD. For instance, several empirical studies show that recognition of emotional expressions [3], interoception [2] and physiological responses to social stimuli [4] function differently in ASD individuals. However, the neural mechanisms involved in atypical embodied representations of emotional expression in ASD has not been systematically investigated. Recent research highlights that visual perception of faces and bodies in typical population is accompanied by parallel activity of visual and somatosensory areas [1, 5-8]. Our EEG study provides the first direct measurement of the activity of the somatosensory cortex during perception of facial emotional expressions in ASD individuals. Our methodology combines Visual and Somatosensory Evoked Potentials (VEPs and SEPs), to isolate effects driven by somatosensory or visual processing. This methodology has already provided evidence of unique contributions of the somatosensory cortex in processing emotional expressions by Sel et al [8] and we are now interested in investigating whether ASD population show different patterns of neural response compared to typical individuals. We are analyzing responses in visual and somatosensory cortical areas in a group of ASD and a control TD participants while they perform a visual emotion recognition task and a control gender recognition task. We predict a modulation of somatosensory evoked potentials driven by emotional expressions processing but not by gender. Moreover, we expect to observe a significant difference in this effect across the two groups.
- Adolphs R, Damasio H, Tranel D, Cooper G, Damasio AR (2000) A role for somatosensory cortices in the visual recognition of emotion as revealed by three-dimensional lesion mapping. J Neurosci 20:2683–2690
- Garfinkel, S. N., Tiley, C., O’Keeffe, S., Harrison, N. A., Seth, A. K., & Critchley, H. D. (2016). Discrepancies between dimensions of interoception in autism: Implications for emotion and anxiety. Biological Psychology, 114, 117–126.
- Harms, M. B., Martin, A., & Wallace, G. L. (2010). Facial Emotion Recognition in Autism Spectrum Disorders: A Review of Behavioral and Neuroimaging Studies. Neuropsychology Review, 20(3), 290–322.
- Hirstein, W., Iversen, P., & Ramachandran, V. S. (2001). Autonomic responses of autistic children to people and objects. Proceedings of the Royal Society B: Biological Sciences, 268(1479), 1883–1888.
- Niedenthal PM (2007) Embodying emotion. Science 316:1002–1005.
- Pitcher D, Garrido L, Walsh V, Duchaine BC (2008) Transcranial magnetic stimulation disrupts the perception and embodiment of facial expressions. J Neurosci 28:8929–8933.
- Pourtois G, Sander D, Andres M, Grandjean D, Reveret L, Olivier E, Vuilleumier P (2004) Dissociable roles of the human somatosensory and superior temporal cortices for processing social face signals. Eur J Neurosci 20:3507–3515.
- Sel, A., Forster, B. and Calvo-Merino, B. (2014). The Emotional Homunculus: ERP evidence for Independent Somatosensory Responses during Facial Emotional Processing. The Journal of Neuroscience, 34 (9), 3263-3267
10) Individual differences in sensory integration predict differences in time perception
Ben Fenner, Gethin Hughes, Nick Cooper and Vincenzo Romei (University of Essex; University of Bologna, Italy)
There is good evidence that individual differences in the temporal resolution of sensory integration relates to significant differences in perception, at extremes relating to conditions such as schizophrenia [1]. Increasingly neural evidence suggests that elements of time perception are embedded within sensory systems [2] however there is little available evidence as to whether, and how, this is influenced by individual differences in the rate of sensory integration. We address this by comparing individual Temporal Binding Windows (TBW; estimated via an adaption of the Simultaneity Judgement task) with individual differences in the filled duration illusion. The filled duration illusion is where intervals filled with a tone reliably appear longer than those where only onset and offset are signalled. Furthermore, we look to establish whether this can be dissociated form the global perceptual differences as found in Schizotypy (measured by the O-life survey). Findings from a large sample (N=103) confirm the filled duration illusion and significantly relate the magnitude of the effect to the size of the TBW. Schizotypy relates only to the TBW. This provides evidence that individual differences in rate of sensory integration relate to time perception, suggesting opportunities for new research.
- Ferri, F., Nikolova, Y. S., Perrucci, M. G., Costantini, M., Ferretti, A., Gatta, V., ... & Sibille, E. (2017). A Neural “Tuning Curve” for Multisensory Experience and Cognitive-Perceptual Schizotypy. Schizophrenia bulletin, 43(4), 801-813.
- Bueti, D., Bahrami, B., & Walsh, V. (2008). Sensory and association cortex in time perception. Journal of Cognitive Neuroscience, 20(6), 1054-1062.
11) Falling for it: The effects of anxiety on balance control
Anna Fielding (Brunel University)
Heightened Fear of Falling (FOF) leads to increased reliance on vision [1;2;3] and changes in balance-correcting responses [4], which leads to increased fall risk and significant costs for older adults (OAs) [5;6;7]. It remains unclear how anxiety affects these physiological responses. This study investigated this process in two age groups (young adults [YAs; n=31] & OAs[n=31]) by inducing height-related threat using virtual reality. Participants stood on a forceplate and experienced a virtual environment; either standing at the top of a cliff (Threat condition) or at ground level (Baseline). For one single trial in each condition, after a short period of standing in the environment the visual scene was rotated backward to create an optic flow simulation consistent with the visual experience of swaying backwards i.e. losing one’s balance. State anxiety and magnitude of postural sway was measured in both Threat and Baseline conditions following the visual perturbation. Both groups reported similarly significantly increased anxiety during Threat condition compared with Baseline. Analysis on a pooled sample revealed significantly increased range of sway at cliff compared to ground; OAs’ range of sway was significantly higher than YAs. However, a significant correlation of the change in anxiety between Baseline and Threat conditions and the associated sway response was only found in YAs, suggesting that the height effect is driven primarily by changes observed in YAs. Thus, while anxiety does appear to be causally related with increased reliance on vison to control balance, it does not fully account for greater reliance on vision in OAs. These results support previous findings that anxiety increases visual reliance for balance control in YAs [8], and elucidate age differences in how balance is maintained during increased anxiety. Future research aims to specify factors contributing to visual reliance in OAs as well as other factors that might influence fall risk.
- Jacob, R. G., Redfern, M. S., & Furman, J. M. (1995). Optic flow-induced sway in anxiety disorders associated with space and motion discomfort. Journal of Anxiety Disorders, 9(5), 411-425. doi:10.1016/0887-6185(95)00021-F
- Ohno, H., Wada, M., Saitoh, J., Sunaga, N., & Nagai, M. (2004). The effect of anxiety on postural control in humans depends on visual information processing. Neuroscience Letters, 364(1), 37-39. doi:10.1016/j.neulet.2004.04.014
- Schniepp, R., Wuehr, M., Huth, S., Pradhan, C., Brandt, T., & Jahn, K. (2014). Gait characteristics of patients with phobic postural vertigo: Effects of fear of falling, attention, and visual input. Journal of Neurology, 261(4), 738-746.
- Cleworth, T. W., Chua, R., Inglis, J. T., & Carpenter, M. G. (2016). Influence of virtual height exposure on postural reactions to support surface translations. Gait & Posture, 47, 96-102.
- Hadjistavropoulos, T., Delbaere, K., & Fitzgerald, T. D. (2011). Reconceptualizing the role of fear of falling and balance confidence in fall risk. Journal of Aging and Health, 23(1), 3-23. doi:10.1177/0898264310378039
- Scuffham, P., Chaplin, S., & Legood, R. (2003). Incidence and costs of unintentional falls in older people in the United Kingdom. Journal of epidemiology and community health, 57(9), 740-744.
- Kempen, G. I., van Haastregt, J. C., McKee, K. J., Delbaere, K., & Zijlstra, G. R. (2009). Socio-demographic, health-related and psychosocial correlates of fear of falling and avoidance of activity in community-living older persons who avoid activity due to fear of falling. BMC Public Health, 9(1), 170.
- Sibley, K. M., Carpenter, M. G., Perry, J. C., & Frank, J. S. (2007). Effects of postural anxiety on the soleus H-reflex. Human movement science, 26(1), 103-112.
12) Extraordinary bodies: How the brain perceives persons with physical disabilities
Helge Gillmeister, Roxanne Armstrong-Moore, Geraldine Goldstein and Chris Devereux-Cooke (University of Essex)
Recent claims have linked perceptual processing styles (configural vs. feature-based) with the (sexual) objectification and dehumanisation of lower-status groups (e.g. women). We combined ERPs and behavioural methods to test this claim, comparing the perception of two groups of disabilities (missing limbs, postural abnormalities) with that of typical bodies in comparably asymmetrical configurations. We used the body inversion effect (BIE) as an index of perceptual processing style, with expected differences in performance for upright (predominantly configurally processed) and inverted (predominantly featurally processed) visual stimuli. Results suggest that, even when upright, bodies with missing limbs in particular are perceived predominantly on the basis of local features rather than configurally, as shown by reduced BIEs in both brain (P1-N1, P2-P3 waves) and behaviour. Disabled bodies also elicited enhanced occipitotemporal scalp positivities at early, perceptual (P1-N1) and later, cognitive-emotional stages (LPP). While these effects may be seen as an index of the objectification and dehumanisation of the disabled, there was mixed evidence to support this from our measures of interpersonal disgust, empathy and attitudes. Observers who responded to bodies with missing limbs with reduced BIEs at P1-N1 and P2-P3, and with enhanced positivities at LPP, also reported more negative attitudes towards disabled persons. At the same time, observers who responded to bodies with missing limbs with reduced BIEs in behavioural measures also had higher trait empathy. We propose that both empathic concern and negative assumptions about disabled persons’ experiences and roles in society may lead to increased attention toward missing limbs in particular. This in turn reduces configural visual processing, and enhances the body part’s emotional salience.
13) Evidence of early gating of sensory information by alpha oscillations inferred from an iconic memory task
Roberto Cecere, Amalia Gomoiu, Stephanie Morand, Monika Harvey and Gregor Thut (University of Glasgow)
Amplitude fluctuations of brain oscillations at baseline have repeatedly been shown to affect the perceptual fate of incoming sensory stimuli. Particularly, pre-stimulus power in the alpha-band (8-14Hz) over occipito-parietal areas has been inversely related to perception, and is thought to reflect gating of sensory information [1-5]. However, despite a comprehensive body of work, there is little consensus on the processing stage at which alpha power affects perception. One prominent, yet untested interpretation is that alpha oscillations inhibit/gate the information flow at an initial, input stage into sensory cortices [6-9]. Alternatively, this influence comes later when information is read out from early sensory cortices to higher-order areas [2,10,11]. Here, we distinguish between these alternatives by investigating whether pre-stimulus alpha-power influences the initial availability versus information decay in an iconic memory task. Specifically, the availability of visual information was sampled at different times between 40 and 300ms after presentation of a multi-item visual display, while concurrently recording multichannel EEG in 27 participants. Logistic regression was then employed to link pre-stimulus oscillations to iconic memory performance across trials within participants, followed by cluster-based statistics across participants and single trial sorting of memory performance. Results revealed a pre-stimulus cluster in the alpha and beta bands over occipito-parietal areas that affected initial availability but not memory decay within participants. A similar, but non-significant trend was observed between participants. Our findings suggest that alpha power is linked to input-gating rather than iconic memory decay. This provides first time evidence for very early gating effects of alpha-band amplitude, complementing evidence for alpha-power influence on later processing stages [11]. Hence, alpha-oscillations seem to affect perception at several stages.
- Thut, G., Nietzel, A., Brandt, S. A., & Pascual-Leone, A. (2006). α-Band electroencephalographic activity over occipital cortex indexes visuospatial attention bias and predicts visual target detection. Journal of Neuroscience, 26(37), 9494-9502.
- Van Dijk, H., Schoffelen, J. M., Oostenveld, R., & Jensen, O. (2008). Prestimulus oscillatory activity in the alpha band predicts visual discrimination ability. Journal of Neuroscience, 28(8), 1816-1823.
- Busch, N. A., Dubois, J., & VanRullen, R. (2009). The phase of ongoing EEG oscillations predicts visual perception. Journal of Neuroscience, 29(24), 7869-7876.
- Thut, G., Miniussi, C., & Gross, J. (2012). The functional importance of rhythmic activity in the brain. Current Biology, 22(16), R658-R663.
- Capilla, A., Schoffelen, J. M., Paterson, G., Thut, G., & Gross, J. (2012). Dissociated α-band modulations in the dorsal and ventral visual pathways in visuospatial attention and perception. Cerebral Cortex, 24(2), 550-561.
- Kelly, S. P., & O'Connell, R. G. (2013). Internal and external influences on the rate of sensory evidence accumulation in the human brain. Journal of Neuroscience, 33(50), 19434-19441.
- Jensen, O., & Mazaheri, A. (2010). Shaping functional architecture by oscillatory alpha activity: gating by inhibition. Frontiers in human neuroscience, 4, 186.
- Romei, V., Gross, J., & Thut, G. (2010). On the role of prestimulus alpha rhythms over occipito-parietal areas in visual input regulation: correlation or causation?. Journal of Neuroscience, 30(25), 8692-8697.
- Lange, J., Oostenveld, R., & Fries, P. (2013). Reduced occipital alpha power indexes enhanced excitability rather than improved visual perception. Journal of Neuroscience, 33(7), 3212-3220.
- Palva, S., & Palva, J. M. (2007). New vistas for α-frequency band oscillations. Trends in neurosciences, 30(4), 150-158.
- Chaumon, M., & Busch, N. A. (2014). Prestimulus neural oscillations inhibit visual perception via modulation of response gain. Journal of Cognitive Neuroscience, 26(11), 2514-2529.
14) Is there anything special about death in the brain? A Frequency-tagging EEG study of death anxiety
Istvan Laszlo Gyimes and Elia Valentini (University of Essex)
Previous research showed that images possessing arousing content lead to changes in the emotional/affective states of the onlooker [1,2]. We combined this evidence with the notion that reminders of death activate an exclusive anxiety mechanism different from the one activated by other types of symbolic threats [3]. This notion is supported by evidence showing how experimental participants verbally reflecting on their own death are then influenced in their opinions and behaviours [3–7]. Here we built on previous research on affective pictures to address a question that has only recently attracted the attention of neuroscientists: Does information about death have a specific effect on brain activity? We tested the hypothesis that passive observation of visual death-related content would trigger greater synchronised brain activity recorded from parietal and occipital regions of the scalp when compared to threat-related content. To address this question we implemented the Fast Periodic Visual Stimulation (FPVS) with neutral images constituting the standard familiar events and the death or threat scenes being the oddball deviant event. In two experiments, we found that images depicting death content evoke lower frequency-tagged EEG response compared to more generic threat images. Visual evoked potentials revealed that a brief change of the scene from neutral to threat content elicits greater amplitude at the late latencies (compatible with a P300 potential), particularly at the parieto-occipital sites. Altogether, our findings suggest that passive observation of death cues does not trigger greater neural synchronisation than that elicited by similarly negative and arousing cues with divergent threatening meaning.
- Lang PJ, Bradley MM, Cuthbert BN. International affective picture system (IAPS): Affective ratings of pictures and instruction manual. Gainesville, FL; 2008.
- Hajcak G, MacNamara A, Foti D, Ferri J, Keil A. The dynamic allocation of attention to emotion: simultaneous and independent evidence from the late positive potential and steady state visual evoked potentials. Biol Psychol. 2013;92(3):447–55.
- Pyszczynski T, Solomon S, Greenberg J. Thirty Years of Terror Management Theory: From Genesis to Revelation. Adv Exp Soc Psychol. 2015;52(January):1–70.
- Niemiec CP, Brown KW, Kashdan TB, Cozzolino PJ, Breen WE, Levesque-Bristol C, et al. Being present in the face of existential threat: The role of trait mindfulness in reducing defensive responses to mortality salience. J Pers Soc Psychol. 2010 Aug;99(2):344–65.
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- Chittaro L, Sioni R, Crescentini C, Fabbro F. Mortality salience in virtual reality experiences and its effects on users’ attitudes towards risk. Int J Hum Comput Stud [Internet]. 2017;101:10–22. Available from: http://dx.doi.org/10.1016/j.ijhcs.2017.01.002
- Bauman Z. Mortality, Immortality and Other Life Strategies. Stanford University Press; 1992. Available from: https://books.google.co.uk/books?id=JYNW-3fjGIoC
15) EEG correlates of implicit and explicit recognition memory for faces
Robin Hellerstedt, Matthew Plummer, Stuart Gibson, Jon Simons and Zara Bergström (University of Kent; University of Cambridge)
Recognition memory is not a single process, but rather involves contributions from different memory systems that may or may not elicit a subjective experience of recognition. Furthermore, subjective recognition experiences are not always based on objective memory, because people can experience highly confident false recognition, suggesting a dissociation between implicit/objective versus explicit/subjective recognition processes. These subprocesses of recognition memory are well characterised for verbal stimuli, but less is known about the different neurocognitive mechanisms that underlie recognition of human faces. It is also unclear whether implicit/objective and explicit/subjective memory mechanisms contribute to face recognition in a graded or all-or-none fashion. We combined EEG measures of brain activity with a continuous measure of face recognition to investigate these issues. Participants studied target faces before engaging in a sequential recognition test. In this test, each of the target faces were presented together with four similar distractor faces, and participants were instructed to select the target face and to rate their confidence in their decision. Face stimuli were created using a face space model algorithm that enabled us to vary the distractors’ similarity to the target on a continuous basis. We sorted EEG responses to faces into event-related potential (ERP) conditions based on distractor similarities to the target or the selected distractor face in case of errors, in order to investigate if ERP correlates of objective and subjective face recognition were elicited in a graded or all-or-none pattern. We also examined the extent to which these ERP correlates of face recognition varied as a function of decision confidence. The study provides a first step towards dissociating the neurocognitive mechanisms that contribute to face recognition.
16) How do we represent observed actions? Investigating the specificity of the sensorimotor encoding of human bodies using EEG
Sonia Abad-Hernando, Alejandro Galvez-Pol, Bettina Forster and Beatriz Calvo-Merino (City, University of London; University College London)
How do we represent observed actions in working memory? Could we differentiate between perceptual or functional roles of embodiment? Recent studies already suggest we hold information in working memory (WM) differently when it contains body information. It has been shown that visual encoding of body stimuli engages electrophysiological activity not only in visual cortices, but also in body-related areas. It was found that persistent activity increased in somatosensory cortex (SCx) only when maintaining body images in WM, whereas visual/posterior regions' activity increased significantly when maintaining non-body images [1]. The aim of this study is to clarify whether this activity is triggered by body stimuli per se, or modulated by the degree in which we embody that stimuli. For this purpose, participants performed a visual WM task [2] in which items to-be-remembered were coloured hand images (depicting 6 different hand positions and in 6 different colours). Each memory array consisted of 1 or 2 hands in each hemifield. In 50% of the trials, we elicited simultaneously VEPs and SEPs by applying task-irrelevant single tactile taps simultaneously delivered to both hands. This allowed us to do a later subtraction in order to isolate and examine the state of the somatosensory cortex (SCx) free of visually evoked activity, exposing its underlying processing during memory encoding and maintenance. We test if SCx areas involved in holding body information in memory are sensitive to the degree of embodiment elicited by different tasks while using the same body stimuli. This study will help us to dissociate the perceptual-functional roles on how working memory encodes body-related information.
- Galvez-Pol, A., Calvo-Merino, B., Capilla, A., Forster, B., 2018. Persistent recruitment of somatosensory cortex during active maintenance of hand images in working memory. Neuroimage 174, 153–163.
- Vogel, E. K., & Machizawa, M. G. (2004). Neural activity predicts individual differences in visual working memory capacity. Nature, 428(6984), 748-751.
17) Reduced semantic selection ability accounts for less coherent speech in old age
Paul Hoffman, Ekaterina Loginova and Asatta Russell (University of Edinburgh)
Semantic knowledge increases across the lifespan. However, the ability of older adults to regulate their access and use of this knowledge has not been investigated. We hypothesised that this ability would show age-related decline, in line with other forms of cognitive control. We also predicted that these declines could explain loss of coherence in older people’s speech, i.e., the increased tendency for older people to produce off-topic, tangential speech. 100 young and older people completed a battery of executive and semantic tests, including tests that probed controlled selection and use of semantic knowledge. 60 participants also provided speech samples elicited by a series of prompts (e.g., how do you look after a dog?). 15 older participants completed the speech elicitation task a second time during fMRI. Speech samples were transcribed and analysed using a novel computational technique that used latent semantic analysis to quantify the degree to which participants remained on-topic. Older people had greater reserves of semantic knowledge but also had specific impairments in semantic selection: they was less able to select the most relevant aspect of knowledge when multiple competing semantic representations were active. Poor semantic selection ability was associated with poor coherence in speech, explaining reduced coherence in the older group. During fMRI, highly coherent speech was associated with greater activation in the inferior prefrontal cortices (BA45), a region strongly linked with semantic selection processes. These data indicate that the status of semantic cognition in later life is more complex than previously assumed. While knowledge accumulates over the lifespan, selection of the most currently-relevant information becomes more difficult. Importantly, older people lose coherence when speaking because they find it hard to select the most relevant aspects of their knowledge to guide speech production.
18) Underlying mechanisms of reward-based motor learning
Peter Holland, Olivier Codol and Joseph Galea (University of Birmingham)
Motor learning - the ability to learn and update how action is performed - is a fundamental process which influences most aspects of our lives. Despite increasing interest in how reward enhances motor learning, the underlying mechanisms remain ill-defined. In particular, the contribution of explicit (conscious) processes to reward-based motor learning is unclear. To address this, we examined subject’s (n=30) ability to learn through reward-based feedback [1]. Subjects held a robotic handle and made reaching movements towards a visual target. The only feedback subjects received was a green tick on successfully hitting the target. Gradually the angle for a successful reach was rotated 25⁰ from the visual target. Only two-thirds of subjects (n=20) showed successful reward-based motor learning. The remaining subjects initially followed the rotation but subsequently began to reach at an insufficient angle and returned to near baseline performance (n=10). Importantly, those that were successful accomplished this largely via explicit processes, evidenced by a reduction in reach angle when asked to remove any strategy. Also, subjects who failed to learn showed decreased sensitivity to errors, a pattern previously found in Parkinsonian patients. In a second experiment, the addition of a secondary mental rotation task completely abolished learning (n=10) providing further evidence that successful reward-based motor learning is dependent on explicit mechanisms. In a follow-up experiment, we replicated the original results in a larger sample (n=120). Additionally, we measured performance on three memory tasks and collected genetic samples in order to examine the role short-term memory and the dopaminergic system in reward-based motor learning. Overall, these results emphasize a pivotal role of explicit processes during reward-based motor learning which has important implications for the efficacy of using reward-based motor learning in motor rehabilitation.
- Holland PJ, Codol O, Galea JM. (2018). The contribution of explicit processes to reinforcement-based motor learning. J Neurophysiol. (Epub ahead of print) doi: 10.1152/jn.00901.2017.
19) Physical exercise is as effective as transcranial direct current stimulation at enhancing long-term memory
Fadi Ifram, Daniel Osei and Amir-Homayoun Javadi (University of Kent)
It is well established that acute physical exercise is beneficial to declarative memory, especially when administered during consolidation. Also beneficial to declarative memory processes is the application of transcranial direct current stimulation (tDCS) over the dorsolateral prefrontal cortex (DLPFC) during encoding. In two studies we employed an old-new recognition paradigm, in which images were used to test the beneficial effects of acute physical exercise and tDCS on declarative memory. This study also tested the combined effect of tDCS and physical exercise on memory performance. In study 1, participants were assigned to the following conditions: physical exercise, anodal, and sham tDCS. In study 2, participants were assigned to the following conditions: physical exercise, physical exercise and anodal stimulation, and sham tDCS on memory performance. During anodal stimulation, participants received tDCS over the left DLPFC for 15 min. During physical exercise, participants were administered an exercise protocol on a cycle ergometer that kept their heart rate between 60-70% of their maximum heart-rate. The results of study 1 provide evidence that tDCS and physical exercise are able to significantly improve declarative memory, as indicated by increased memory performance scores on the old-new recognition task. The results of study 2 indicate that a combination of physical exercise and tDCS does not lead to further enhancements in memory performance over physical exercise when administered on its own. In conclusion, our results demonstrate that physical exercise is, at least, as good as tDCS at enhancing long-term memory performance.
20) The neuromodulatory effects of L-DOPA across human verbal memory processes
Hanna K. Isotalus, John P. Grogan, James Selwood, Nerea Irigoras Izagirre, Alex Howat, Lisa Knight, Risto A. Kauppinen and Elizabeth J. Coulthard (University of Bristol; North Bristol NHS Trust)
Long term memory can be divided into three core phases of processing; encoding, consolidating, and retrieving. In Parkinson’s disease verbal long term memory is improved with exogenous dopamine administration during consolidation and retrieval but impaired when dopamine is administered during encoding. Understanding dopamine’s roles across memory processes may have future implications in targeting therapeutics in amnesic disease. Here, we tested the effect of L-DOPA administration across verbal recognition memory processes in healthy ageing. In a placebo-controlled double-blind randomised crossover trial, 33 healthy elderly (65+ years) adults performed a verbal recognition memory task. Volunteers first learnt a word list on Day 1 without medication. On Day 2, to examine the effect of dopamine on retrieval, they were dosed with 150mg L-DOPA or placebo before their memory was tested. To target encoding, they then learnt a novel word list with memory tested immediately, and 1, 3, and 5 days later, with unique targets at each test. There was no difference in recognition accuracy between L-DOPA and placebo in either experiment and Bayesian analyses provided moderate support against L-DOPA affecting retrieval (BF₀₁=4.243) or encoding (BF₀₁=4.300). However, post-hoc analyses revealed that L-DOPA during encoding enhanced retrieval 3-days later for those with high trait depression or anxiety (r =.425 p=.030; r =.467, p =.016, respectively). Our findings suggest that exogenous dopamine does not enhance encoding or retrieval in healthy ageing, and that earlier results may be explained by dopamine boosting consolidation. Our ongoing placebo-controlled clinical trial investigates the efficacy of L-DOPA administration in targeting consolidation during sleep in healthy ageing but these data have not been unblinded.
21) Rhythmic encoding improves recognition memory
Alexander Jones and Emma Ward (Middlesex University, London)
There has recently been an increased interest in the way in which temporal expectancies shape perception and drive behaviour. Research has observed that intrinsic neural oscillations can entrain to external rhythms by aligning the firing pattern of neurons. Entraining neural oscillations has shown to enhance perception and facilitate behaviour for stimuli that appear in phase with the rhythm, yet relatively little is known about how temporal expectation during encoding influences subsequent memory. Participants in the present study were presented with a rapid succession of everyday objects in an encoding phase and asked in a subsequent recognition test phase to judge whether individually presented objects were presented before (old) or not (new). Importantly, the presentation of objects in the encoding phase followed a either rhythmic or arrhythmic temporal pattern, of which participants were not made aware. Recognition was significantly greater for items that were presented rhythmically compared to those that were presented arrhythmically. There was evidence of entrainment of neural oscillations with increased phase locking for rhythmically over arrhythmically presented stimuli during encoding. Moreover, memory specific ERP components at test phase were influenced by rhythmic encoding. Specifically, the FN400 old/new effect was present in both conditions, but a late positive component (LPC) old/new effect was only observed for rhythmically encoded items. This parietal old/new effect (LPC) has been proposed to be an index of recollection, specifically linked to memory for the contextual details associated with the encounter with the item. The study provides new evidence through EEG and behavioural measures that presenting stimuli in a rhythmic manner provides a benefit to recognition memory.
22) Native listeners’ intelligibility of vowel hyperarticulation and its relevance in speech learning in adults
Jayanthiny Kangatharan, Maria Uther and Fernand Gobet (Brunel University; University of Winchester; University of Liverpool)
Stretched vowel space is one acoustic-phonetic feature that has been reliably revealed to naturally be part of clear speech [e.g. 1, 2], and to correlate with speech intelligibility [3]. It was also found that those speakers, who can naturally articulate phonetic contrasts accurately on a segmental level and employ larger vowel space, are more intelligible than those with smaller vowel paces [4] To this date, only an association between vowel space expansion and speech intelligibility has been revealed. Nonetheless, because correlation does not necessarily imply causation, to this date, no study has directly tested whether speech with vowel expanded vowel space produced under naturalistic circumstances, and not merely by instructing speakers to speak as if they are talking to foreign listeners or hearing-impaired listeners are more intelligible than speech samples with non-expanded vowel space in a controlled setting. This study explored whether expanded vowel space, as elicited in speech to infants (IDS) leads listeners to perceive enhanced intelligibility. Twenty-one native speakers of English completed a transcription and confidence rating task, a goodness rating task and a clarity rating task to evaluate the intelligibility of hyperarticulated speech samples, which were directed by mothers to infants as compared to clear read speech samples produced by mothers. Statistical analysis showed higher transcription accuracy and clarity ratings for speech by mothers directed at infants versus clear read speech produced by mothers. Results suggest that speech with vowel hyperarticulation and other acoustic-phonetic features seems to enhance intelligibility to infants. The implications of the results are discussed with regard to current theories of speech communication and interaction.
- Krause, J., & Braida, L. (2004). Acoustic properties of naturally produced clear speech at normal speaking rates. Journal of the Acoustical Society of America, 115, 362-738.
- Uther, M., Knoll, M., Burnham, D.(2007) Do you speak E-NG-L-I-SH? A comparison of foreigner-and infant-directed speech. Speech Communication, 49, 2-7.
- Bond, Z., & Moore, T. (1994). A note on the acoustic-phonetic characteristics of inadvertently clear speech. Speech Communication, 14, 325-337.
- Bradlow, A., Torretta, G., & Pisoni, D. (1996). Intelligibility of normal speech. I. global and fine-grained acoustic-phonetic talker characteristics. Speech Communication, 20, 255-272.
23) Laterality effect of the illusory body space
Beatrix Zsidó Lábadi, András Norbert, Orsolya Inhóf, Eszter Kohn and Gergely Darnai (Univeristy of Pécs)
A growing body of research shows that right hemispheric networks support the illusory body space in the induction of the Rubber Hand Illusion (RHI) and subjects with a lower degree of lateralization and/or low interoceptive abilities are more susceptible to the bodily illusion [1]. However there is no information about how hemispheric lateralization and interoceptive ability relate to the body space network. In present study neurologically healthy adults have been studied using two experimental tasks measuring the body ownership for both hands with RHI and the pseudoneglect before and after the RHI induction with line bisection task. We also measured the degree of the laterality and interoceptive abilities. Our findings showed greater body ownership effect with greater proprioceptive drift and greater subjective feeling of ownership when the stimuli delivered on the left hand. Low interoceptive ability was associated with a stronger illusion with greater proprioceptive drift. The result of the line bisection task showed that the pseudoneglect was reduced only by RHI application to the left hand. In line with previous studies of functional hemispheric asymmetry for spatial processing, the left sided rubber hand has a greater access to the the right hemispheric network and shift subjective body midline to the right.
- Hach, S. and Schütz-Bosbach, S. (2014). In (or outside of) your neck of the woods: laterality in spatial body representation. Frontiers in Psychology (5) 123. 1-12.
24) Mobile brain imaging identifies the re-allocation of attention during real-world activity
Simon Ladouce, David Donaldson, Paul Dudencko and Magdalena Ietswaart (University of Stirling)
Laboratory studies have long demonstrated that human attention has an inherently limited capacity. How limited attentional resources are distributed during real-world behaviour is currently unknown. Here we characterise the allocation of attention across multiple sensory-cognitive processing demands during naturalistic movement. We used a neural marker of attention, the Event Related Potential (ERP) P300 effect, to show that attention allocated to the detection of infrequent target stimuli is reduced when human participants walk down a familiar hallway compared to when they stand still. In a second experiment we show that this reduction in attention is not caused by the act of walking per se. A third experiment identified the independent processing demands driving reduced attention to target stimuli during motion. A significant reduction in attention occurred when isolating the capture of attention by inertial stimulation, and a larger reduction when isolating attentional capture by visual stimulation. Furthermore, the data reveal that the reduction in attention seen during walking reflects the linear and additive sum of the processing demands produced by visual and inertial stimulation. The mobile cognition approach used here shows how limited resources are precisely re-allocated across competing sensory modalities when attention is divided, demonstrating that attentional capture can be quantified during real world behaviour.
25) Temporal precision of predicting perceptual input from dynamic contexts in the early visual cortex
Yulia Y. Lazarova, Lucy S. Petro, Fabiana M. Caravalho, Angus T. Paton, Fraser W. Smith and Lars Muckli (University of Glasgow; University of Sao Paulo, Brazil; University of East Anglia)
The brain forms internal representations of the environment through repetitive exposure to spatiotemporal regularities in our surroundings. This allows the brain to proactively perceive sensory information by predicting upcoming perceptual input [1]. We investigated how predictions affect processing in the early visual cortex in the context of complex scenes. Using an event-related design we presented participants with short videos of naturalistic scenes and recorded brain activity from areas V1-V3 using 3T fMRI. Each video consisted of a priming sequence of images interrupted by a 800ms interval, followed by a single test frame. It came from one of four possible points of the video–an exact match of the resumed video after the gap, or taken from too late (4000ms) or too early (300, 600ms) point after the gap onset. The task was to mentally extrapolate the video and rate the test frame as matching, early, or delayed. In a control condition the images in the video were presented out of order, precluding the perception of coherent motion and hindering the formation of expectations about the test frame after the interval. To study the temporal dynamics of the occurring perceptual processes, we increased image exposure time from 100ms to 200ms. General linear model deconvolution analysis revealed lower BOLD response in V1 and V3v to the predictable matching test frame compared to the late mismatching one (4000ms). This signal attenuation was not seen in the control condition, where predicting upcoming input was impossible. Such activation drop in response to the coherent motion videos compared to the non-coherent ones was only seen in V1 when priming images were presented for 200ms but not for 100ms. We demonstrate that predictions about motion in complex scenes exist in the early visual cortex. They are temporally-specific and can extrapolate over time. It takes more than 100ms for predictive processes to take effect, suggesting recurrent processing in visual cortex.
- Bar, M. (2009). The proactive brain: memory for predictions. Philosophical Transactions Of The Royal Society B: Biological Sciences, 364(1521), 1235-1243. doi: 10.1098/rstb.2008.0310
26) Recruitment Issues with non-invasive brain stimulation in stroke patients
Gemma Learmonth, Keith Muir, Christopher Benwell, Matthew Walters and Monika Harvey (University of Glasgow; Queen Elizabeth University Hospital)
Up to 80% of people who experience a stroke that affects the right hemisphere suffer from hemispatial neglect. This syndrome is debilitating, impedes rehabilitation, and is a strong independent predictor of poor recovery. We carried out a pilot trial of transcranial direct current stimulation (tDCS) and a behavioural rehabilitation programme, alone or in combination, on 60 subacute patients with hemispatial neglect (>4 weeks post stroke). We randomly allocated patients to 10 sessions of 15 minutes each of 1 mA constant tDCS, 10 sessions of a "rod lifting" intervention, both interventions combined, or standard care (a control task). Our primary outcomes were recruitment and retention rates, with secondary outcomes measuring effect size and variance scores of neglect, activities of daily living and quality of life tests, assessed directly after the interventions and at 6 months follow up. Of 288 confirmed stroke cases referred (representing 7% of the screened population), we randomised only 8% (0.6% of stroke cases overall), with the largest number of exclusions (91/288 (34%)) due to medical comorbidities that prevented patients from undergoing 10 intervention sessions. We recruited 24 patients over 29 months, where 88% (21) of these completed testing and 67% (14) completed the 6 month follow up testing. We established poor feasibility for a larger trial, with a lower recruitment rate than envisaged (24 recruited out of 60 planned). A definitive hemispatial neglect trial using non-invasive brain stimulation, either with or without behavioural training, will require a broad recruitment base, and the intensity, duration and location of the interventions will have to be carefully selected.
27) Investigating neural correlates of embodiment through facial emotion perception, its relation to interoception and personality traits
V. Meletaki, B. Calvo-Merino, I. Arslanova and B. Forster (City, University of London)
Embodiment theories and studies have suggested that there is activation in somatosensory cortices at early stages of facial expression processing that might work independently from visual processing [1, 2]. Our study further investigates how different emotions modulate this early somatosensory activity and if this measurement of embodiment is related to interoception (i.e. interoceptive accuracy and awareness) or personality traits (i.e. depression, alexithymia). At the present study participants were shown photos of faces expressing happiness, anger, sadness and neutral, while measuring their electrophysiological activity. We measured their interoceptive abilities and their levels of depression and alexithymia (by means of Beck Depression Inventory and the Toronto Alexithymia Scale respectively). We calculated the visual evoked potential (VEP) and the somatosensory evoked potential (SEP) that was calculating by subtracting the visual only conditions from the tactile conditions. In accordance with the literature, results showed emotion modulation on the VEPs at P200. Regarding SEPs, we have a main effect of emotion on 100-120”, where significant differences in amplitude were found between the emotions happy, sad and angry and neutral. We further correlated the SEP amplitude of emotion with depression and alexithymia scores showing significant interactions between depression score and amplitude of sad emotion. These results provide novel evidence for distinct neural signatures for processing different emotions. The present study is of interest due to its innovative and interdisciplinary methodology as we combine the neural index of embodiment as proposed by Sel et al. [2] with psychometric and interoceptive measures.
- Pitcher, D., Garrido, L., Walsh, V. and Duchaine, B.C. (2008). Transcranial Magnetic Stimulation disrupts the perception and embodiment of facial expressions. The Journal of Neuroscience, 28 (36), 8929-8933
- Sel, A., Forster, B. and Calvo-Merino, B. (2014). The Emotional Homunculus: ERP evidence for Independent Somatosensory Responses during Facial Emotional Processing. The Journal of Neuroscience, 34 (9), 3263-3267
28) When effort itself becomes rewarding: The interaction between task difficulty and reward contingency in the striatum
Stefanie Meliss, Michiko Sakaki, Kou Murayama, Madoka Matsumoto, Yukihito Yomogida, Kaosu Matsumori, Ayaka Sugiura and Kenji Matsumoto (University of Reading; University of Tokyo Hospital, Japan; National Center of Neurology and Psychiatry, Japan; Tamagawa University, Japan; Wayne State University, United States)
Many reward learning theories posit that effort is aversive, indicating that reward system would be least responsive to difficult and effortful options. However, research in psychology suggests that effort itself can be rewarding. To test this possibility, we examined the relationship between task difficulty and reward network with 51 healthy participants using functional magnetic resonance imaging. Participants were assigned to three groups: Control group participants did not receive any rewards (i.e. they worked on the task out of intrinsic motivation), whereas reward group participants received monetary rewards based on their performance. In the gambling group, task success or failure was probabilistically determined (not by the performance of participants). In all groups, participants worked on a game-like task that had three difficulty levels: easy, moderate, and difficult. The behavioural results showed that the effects of difficulty level on self-reported motivation differed between the groups, F(4,96) = 25.18, p < .001. In the control group, participants were more motivated with increasing task difficulty, whereas the gambling group showed the opposite pattern. Furthermore, the motivation ratings in the reward group followed an inverted U shape, exhibiting the highest motivation for a moderately difficult task. The neuroimaging analyses mirrored these findings: a bilateral cluster in the ventral striatum showed similar patterns of activation as observed in behavioural analysis (p < .05, family-wise error corrected). Exploratory functional connectivity analyses showed temporal correlation between activity in the striatal peak voxel and the lingual gyrus (p (uncorrected) < .001). Our results indicate that contrary to the current popular reward learning theories, effort has differential effects in the reward network depending on context and is not generally aversive.
29) Attentional capture by salient distractor in a tactile search task.
Carlos Mena-Poblete, Kadi Lang and Elena Gherri (University of Edinburgh)
Previous studies on tactile search have only used one target and homogenous distractors (fillers) (Forster, Tziraki, & Jones, 2015). Therefore, it remains unclear whether a distractor that shares a relevant feature will capture attention in a similar fashion to what has been observed in vision (Gaspar & McDonald, 2014; Hickey, McDonald, & Theeuwes, 2006). We used a task with 4 vibrotactile stimuli with different frequencies on 4 locations (2 fingers of 2 hands). Participants were asked to respond to the elevation of the target (top vs bottom fingers) while ignoring other simultaneous stimuli. There were 4 different conditions: target with three fillers (target only trials), distractor with three fillers (distractor only trials), target and distractor simultaneously the same hand (same side trials) or to the opposite hand (opposite sides trials) and two fillers. Results demonstrated that the distractor captured attention, resulting in slower RTs and lower accuracy on distractor present trials as compared to distractor absent trials. ERP analyses show the presence of the N140cc on target only and same side trials. Interestingly, there was a reliable N140cc also on distractor trials suggesting that the distractor was able to capture attention. In addition, the N140cc was reduced on opposite sides trials as compared to target only trials. This suggests that although participants were able on average to direct attention to the target, the presence of the distractor had detrimental effects on search performance.
- Forster, B., Tziraki, M., & Jones, A. (2016). The attentive homunculus: ERP evidence for somatotopic allocation of attention in tactile search. Neuropsychologia, 84, 158–166. https://doi.org/10.1016/j.neuropsychologia.2016.02.009
- Gaspar, J. M., & McDonald, J. J. (2014). Suppression of Salient Objects Prevents Distraction in Visual Search. Journal of Neuroscience, 34(16), 5658–5666. https://doi.org/10.1523/JNEUROSCI.4161-13.2014
- Hickey, C., McDonald, J. J., & Theeuwes, J. (2006). 3) Electrophysiological Evidence of the Capture of Visual Attention. Journal of Cognitive Neuroscience, 18(4), 604–613. https://doi.org/10.1162/jocn.2006.18.4.604
- Hilimire, M. R., Mounts, J. R. W., Parks, N. A., & Corballis, P. M. (2009). Competitive interaction degrades target selection: An ERP study. Psychophysiology, 46(5), 1080–1089. https://doi.org/10.1111/j.1469-8986.2009.00846.x
30) ‘Is this your card?’ Group and individual analyses of EEG theta during a modified guilty knowledge task
Roger Moore, Amy Prior, Tom Lockhart and Thanusha V. Manohor (University of Portsmouth)
Lying is suggested to be cognitively demanding since it requires inhibition of the truth and generation of a new response. Increased cognitive load influences brain activity; therefore the distinction between lies and truths should be able to be differentiated by EEG. Increased EEG theta activation at frontal brain regions is proposed to be a result of increased task demands [1] so it is assumed that this may be reflected in differentiated EEG response during lying. Exploratory research was conducted into changes in EEG theta activity during initial reaction to guilty knowledge stimuli. EEG from 39 participants were recorded (14 electrodes) whilst participants underwent a modified version of the Guilty Knowledge Task [2], denying the identity of a concealed card, whilst also being shown control and irrelevant cards. Group: EEG analysis considering low (4-6Hz) and high theta (6-8Hz) power from aggregated data recorded across the midline from anterior - posterior cortical regions (yielding 5 virtual electrodes) revealed that power in both theta wavebands significantly reduced during lying relative to truth telling at all five of the virtual midline electrodes. Individual: The trend described in the group analyses differentiated lying from truth telling in 84.62% of the sample when low theta at the most anterior virtual electrode was considered, and 79.49% when low theta for the most posterior virtual electrode. When response at these two regions were considered together, discrimination accuracy rose to 94.87%. Whilst these data showed an unexpected trend (i.e. theta reduction when lying rather than increase) they strongly suggest that low theta EEG could potentially act as a useful tool in discriminating truthful from deceptive behaviour. The current study suffers from low ecological validity but this will be addressed in planned follow up work.
- Gevins, A. S., Zeitlin, G. M., Doyle, J. C., Schaffer, R. E., & Callaway, E. (1979). EEG patterns during “cognitive” tasks. Analysis of controlled tasks. Electroencephalography and clinical neurophysiology, 47(1), 704-710.
- Merzagora, A. C., Bunce, S., Izzetoglu, M., and Onaral B. (2006). Wavelet analysis for EEG feature extraction in deception detection. Engineering in Medicine and Biology Society,1, 2434-2437.
32) The role of neuromodulation on cognitive processing and enhancement in face perception
Montserrat Gonzalez Perez (University of East London)
Faces are important and among the most interesting stimuli on visual attention [1]; we rely on faces for social interactions. Face processing forms part of our everyday brain activity; it seems effortless the way we identify familiar and unfamiliar faces such as friends, family, celebrities or a complete stranger. Faces can also provide moods and emotions: eyes can provide gaze direction and lips can provide lip reading. All this compounded information concentrated in our faces can provide crucial information for us to behave appropriately in social interactions. When brain injury in the face processing network, the individual loses the ability to identify faces [2] ‘face blindness’. The aim of the current study was to use neuromodulation (techniques that directly affect the brain’s neurophysiology), specifically tACS, to causally demonstrate the functional relevance of GBO in face-processing. In addition, the category- and the process-specificity of tACS effects, as well as the role of the timing of neuromodulation with respect to the execution of cognitive tasks are still unknown. In this single-blind, sham-controlled study, was examined whether the administration of tACS over the right occipital cortex of healthy volunteers (N=48) enhances performance on perceptual and memory tasks involving both face and object stimuli. No study to date has investigated whether (tACS) can causally enhance face processing. Neuromodulation was delivered in three groups condition: Gamma 40 Hz, Theta 5 Hz and Sham. The results showed that tACS neuromodulation slightly enhances the perception and memory performance of both faces and objects. This study add relevant information about the cognitive processes and visual stimuli that can be modulated by tACS, and about the design of effective neuromodulation techniques and protocols, which have implications for advancing theories in cognitive neuroscience and possible clinical application.
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- Vossen, A., Gross, J., & Thut, G. Alpha Power Increase After Transcranial Alternating Current Stimulation at Alpha Frequency (alpha-tACS) Reflects Plastic Changes Rather Than Entrainment. Brain Stimul. 8 (3), 499-508 (2015)
- Veniero, D., Vossen, A., Gross, J., & Thut, G. (2015). Lasting EEG/MEG Aftereffects of Rhythmic Transcranial Brain Stimulation: Level of Control Over Oscillatory Network Activity. Front Cell Neurosci, 9, 477. doi: 10.3389/fncel.2015.00477
32) ERP correlates for retrieval-induced updating of face memories
Matthew Plummer, Robin Hellerstedt, Stuart Gibson, Jon Simons and Zara Bergström (University of Kent; University of Cambridge)
Episodic memories are prone to updating, whereby errors made during recollection attempts can update the original memory [1,2]. Furthermore, ERP correlates of episodic memory updating are distinct from ERP markers of retrieval success [1,3]. However, it is not clear whether similar retrieval-induced updating mechanisms operate during item recognition, such as when we recognise faces. This issue was investigated in the present EEG experiment. We created face stimuli using a face space model algorithm [4] that enabled us to measure face recognition accuracy and updating on a continuous scale. Participants first learnt a number of face targets before an initial recognition test. Here, each trial presented a face target with distractor foil faces in a sequential recognition design, and participants were required to select the face target and report their confidence in their decision. This test was followed by a second test of identical design to the first. Behaviourally, high confidence responses from the first test were more likely to be repeated in the second test regardless of accuracy. This supports the notion that recognition errors made with high confidence were encoded into memory, thereby updating participants’ face memories. EEG analysis of the first test separated the ERP effects that were associated with retrieval success from the ERP effects that were predictive of updating, and investigated how these effects were modulated by confidence. The results show the neural processes engaged during face recognition that are associated with retrieval-induced distortions of face memories.
- Bridge, D. J. & Paller, K. A. (2012). Neural Correlates of Reactivation and Retrieval-Induced Distortion. The Journal of Neuroscience, 32(35), 12144-12151.
- St. Jacques, P. L., Olm, C. & Schacter, D. L. (2013). Neural mechanisms of reactivation-induced updating that enhance and distort memory. PNAS, 110(49), 19671-19678.
- Liu, X. L., Tan, D. H. & Reder, L. M. (2018). The two processes underlying the testing effect- Evidence from Event-Related Potentials (ERPs). Neuropsychologica, 2018, 77-85.
- Solomon, C., Gibson, S. J. & Mist, J. J. (2013). Interactive evolutionary generation of facial composites for locating suspects in criminal investigation. Applied Soft Computing, 13(7), 3298-3306.
33) Electrical brain activity associated with false memory-related increases to subsequent recognition.
Louisa Salhi, Arianna Moccia, David Vogelsang and Zara Bergstrom (University of Kent; University of California, USA)
Incidental encoding takes place in many situations, including during old/new recognition tasks where new “foil” items are encoded to different extents depending on modulatory processes occurring during retrieval attempts [1]. Our recent findings suggest that one such modulator is false familiarity, since foil words that were falsely recognised as previously seen on a first test were subsequently more likely to be accurately recognised as previously seen on a final surprise test compared to other foil words that were correctly identified as new on the first test. This pattern may be due to false familiarity facilitating context encoding during the first test [2], or due to false familiarity “carrying over” across multiple tests (i.e. persistent false memories). In this EEG study, we investigated the neurocognitive mechanisms that underlie spontaneous false memory during an old/new task and how this relates to increased subsequent recognition. Source judgments during the subsequent old/new task also enabled us to examine if the false memories enhanced test context encoding or simply persisted without enhancing encoding. Initial behavioural findings replicate prior results by showing increased subsequent recognition for items that produced false familiarity on the first test. Source judgments indicated that this was mostly due to persistent false memories rather than familiarity facilitating encoding. EEG findings will provide more information on the neural mechanisms driving this effect, and how they relate to well-established markers of familiarity and recollection [3]. The results will also be used to inform the theoretical debate regarding whether there are dissociable novelty and familiarity processes during recognition tasks [4].
- Vogelsang, D.A., Gruber, M., Bergström, Z.M., Ranganath, C., & Simons, J.S. (2018). Alpha oscillations during incidental encoding predict subsequent memory for new "foil" information. Journal of Cognitive Neuroscience, 30, 667-679.
- Reder, L. M., Liu, X. L., Keinath, A., & Popov, V. (2016). Building knowledge requires bricks, not sand: The critical role of familiar constituents in learning. Psychonomic Bulletin & Review, 23(1), 271-277.
- Rugg, M. D., & Curran, T. (2007). Event-related potentials and recognition memory. Trends in cognitive sciences, 11(6), 251-257.
- Daselaar, S. M., Fleck, M. S., & Cabeza, R. (2006). Triple dissociation in the medial temporal lobes: recollection, familiarity, and novelty. Journal of Neurophysiology, 96(4), 1902-1911.
34) Assessing and adjusting for publication bias in the relationship between anxiety and the error-related negativity
Blair Saunders and Michael Inzlicht (University of Dundee; University of Toronto, Canada)
Many clinical neuroscience investigations have suggested that trait anxiety is associated with increased neural reactivity to mistakes in the form of an event-related potential called the error-related negativity (ERN). Two recent meta-analyses indicated that the anxiety-ERN association was of a small-to-medium effect size (rs =.-25 and -.28), however, these prior investigations did not quantitatively adjust these effect sizes for publication bias. Here, in an updated meta-analysis (k=58, N=3819), we found support for an uncorrected effect size of r =-.193, and applied a range of methods to test for and correct publication bias (trim-and-fill, PET, PEESE, Peters’ test, three-parameter selection model). The majority of bias-correction methods suggested that the correlation between anxiety and the ERN is non-zero, but smaller than the uncorrected effect size (average adjusted effect size: r =-.118, range: r =.-045 to -.179). Moderation analyses also revealed more robust effects for clinical anxiety and anxious samples characterised by worry, whereas mixed anxiety was not associated with the amplitude of the ERN. Our results suggest that future research exploring the anxiety-ERN relationship would benefit from increased statistical power and the adoption of certain open science practices.
36) Individual peak alpha frequency in touch – cognitive and methodological implications
Jonathan Silas and Alexander Jones (Middlesex University, London)
Oscillations in the alpha frequency range (8-12Hz), measured using electroencephalography (EEG), have been shown to have a functional role in cognition and attention in particular. For example, voluntarily shifting covert attention to one side of space leads to a decrease of alpha activity over the contralateral hemisphere. More recently, interest has turned to the notion that across individuals there is notable variance in the peak of the frequency, and these peaks are dependent on task demands or the participant’s “state”. Here we directly contrast four separate tasks commonly known to modulate alpha power, in a within subjects design. Using a somatosensory cue, participants (N=21) either oriented (1) endogenous or (2) exogenous attention to the right or left hand and response times were measured. In a passive task (3) participants received tactile stimuli at regular intervals to one hand only, akin to studies determining peak alpha desynchronization for subsequent brain stimulation. Finally, EEG was measured from participants whilst at rest (4) when no stimuli were presented. Results show a difference in lateralized alpha power depending on the task. Interestingly, we also observe differences in peak frequencies across tasks within the same individual. These findings have key implications in terms of understanding the functional role of alpha oscillations and how they vary across different states and individuals. Furthermore, recent advances in transcranial alternating current stimulation (tACS) have relied on ‘individualising’ EEG frequencies for subsequent stimulation. We suggest, that such frequency ‘individualisation’ or ‘localisation’ for the purposes of tACS, requires task-specific functional localisation.
36) The effects of reward on sequential reaching movements
Sebastian Sporn and Joseph M. Galea (University of Birmingham)
The expectation of receiving reward has been shown to improve the speed and accuracy of eye movements and simple reaching tasks [1,2]. Capitalising on the speed-accuracy trade-off and its implications for human and animal behaviour, these studies demonstrate that reward expectancy produces similar shifts in the trade-off curve as motor skill training [3,4]. This effect of reward to energise movements and actions has been described as motivational vigour [5] and could be of beneficial use in rehabilitation. However, it remained an open whether reward expectancy can also invigorate more complex sequential movements. We addressed this question using a novel paradigm which consisted of participants making sequential reaching movements to 4 targets arrayed as a novel shape. Each participant was exposed to a rewarded and non-rewarded shape. Rewarded shapes were cued with two stimuli (auditory and visual) and monetary reward was calculated based on movement speed using a closed-loop design. Importantly, if any of the targets were missed then a trial was deemed a failure. Hence, to receive reward participants had to maintain accuracy whilst improving movement speed. Experiment 1 showed a significant effect of reward expectancy on movement time (MT), which increased over the course of the training block (p < 0.0001 for early vs late performance in training). By the end of training (150 trials), the rewarded shape was being performed ~300ms faster than the non-rewarded shape whilst maintaining a similar level of accuracy. Experiment 2 replicated these findings (p < 0.0001) and in addition found a consolidation effect 24 hours later (p = 0.0001 for late training NS vs day 2 performance). Taken together, our findings demonstrate that complex sequential actions can be invigorated when paired with reward.
- Takikawa, Y., Kawagoe, R., Itoh, H,, Nakahara, H., and Hikosaka, O. (2002). Modulation of saccadic eye movements by predicted reward outcome. Experimental Brain Research ,142,284-291.
- Choi, J. E. S., Vaswani, P. A., & Shadmehr, R. (2014). Vigor of movements and the cost of time in decision making. The Journal of Neuroscience, 34, 1212–1223.
- Manohar, S.G., Chong, TT-J., Apps, M.A.J., Batla, A., Stamelou, M., Jarman, P.R., Bhatia, K.P., Husain, M. (2015). Reward Pays the Cost of Noise Reduction in Motor and Cognitive Control. Current Bioogyl ,25,1707–1716.
- Manohar, S.G., Finzi, R.D., Drew, D., Husain, M. (2017). Distinct Motivational Effects of Contingent and Noncontingent Rewards. Psychological Science, 28,1016–1026.
- Summerside, E., Shadmehr, R., Ahmed, A.A. (2018). Vigor of reaching movements: reward discounts the cost of effort. Journal of Neurophysiology, 0 0:0.
37) Neuroimaging to identify the underlying mechanisms of human 3D depth perception
Makoto Uji, Ines Jentzsch, Angelika Lingnau, James Redburn, Ian Cavin and Dhanraj Vishwanath (University of St Andrews; Royal Holloway University of London; NHS Tayside)
Viewing a real scene or stereoscopic image with both eyes can yield a vivid qualitative impression of tangibility and real separation in depth called stereopsis. This impression is conventionally thought to be by-product of binocular disparity processing. However, a similar qualitative impression can also be induced under monocular viewing of single pictures through an aperture. Previous neuroimaging studies focused primarily on identifying neural mechanisms for deriving depth from disparity. There has been little research examining the subjective impression of stereopsis. We conducted two experiments: (1) fMRI and (2) EEG study to identify the neural substrates of the subjective impression of stereopsis. In Experiment 1, 7 participants viewed scrambled or intact images of natural 3D scenes under three different viewing conditions [Binocular (pictorial), Monocular aperture (pictorial), Stereoscopic (colour anaglyph)] while performing a control visual attentional task. Fixed-effects GLM contrasts isolating stereopsis demonstrated a selective recruitment of posterior parietal regions, but not ventral or occipital regions for both monocular and binocular stereopsis. In Experiment 2, 12 participants viewed 2D and 3D pictorial images under four different viewing conditions [Binocular, Monocular, Binocular aperture, Monocular aperture] while performing a control visual attention task. We localized EEG oscillatory sources (beamformer techniques), and conducted time-frequency analysis to examine power change in alpha (8-13Hz) and gamma (55-80Hz) frequency. Differential gamma synchronization was observed within the parietal cortex for the contrast isolating monocular stereopsis. Together, these initial studies suggest that neural activity in posterior parietal cortex might underlie the qualitative impression of stereopsis.
38) The role of hippocampal volume and the action of co-beneldopa on consolidation of associative memory in healthy elderly
Rachel L. Williams, Hanna Kristiina Isotalus, John P. Grogan, Michael J. Knight, Risto A. Kauppinen and Elizabeth J. Coulthard (University of Bristol; North Bristol NHS Trust)
Healthy aging and several age-related amnesic diseases have negative impacts on memory consolidation and the hippocampus (HC). Dopamine (DA) is a neuromodulator of the HC and increasing DA levels may enhance memory consolidation. The aim of this study was to investigate the relationship between DA, associative memory and the HC. We hypothesised that DA medication improves consolidation of paired associates (PA), compared to placebo, and that larger HC subfield volumes, as measured by MRI, are associated with better associative memory. In this double-blind placebo-controlled randomised clinical trial, 30 healthy elderly adults learnt 48 paired images on a computer screen. Participants were instructed to remember which pictures were shown together. After learning, either co-beneldopa (CR 50/200mg) or placebo was administered. Early recall of 24 pairs was tested 1h after learning and late recall of all items was tested the following morning (~12h). Each volunteer underwent both drug conditions. The HC and its subfields were imaged on a 3T MRI scanner using an in-house developed CPMG-like sequence and segmented using the automated ASHS procedure. We have currently unblinded 5 participants with a further 25 enrolled. Our results so far have confirmed the feasibility of this study with drugs being well tolerated and successful segmentation of HC subfield volumes. Preliminary results (n=5) show mean (±SDs) accuracy for PA image pairings at late recall was 95% (±11%) in the placebo and 83% (±24%) in the DA condition. Mean (±SD) left and right HC subfield volumes were 1181.93mm3 (±181.25) for cornu ammonis (CA) 1, 17.53mm3 (±5.97) for CA2, 65.94mm3 (±26.58) for CA3, 735.00mm3 (±76.75) for dentate gyrus, 354.16mm3 for subiculum (±56.31) and 5122.16mm3 (±753.76) for total HC volume. We now proceed to collect data from 30 participants to investigate the potential use of overnight co-beneldopa for improving associative memory.
39) Inner speech during silent reading of direct quotations is linked to theta-band neural oscillations
Bo Yao, Briony Banks, Jason Taylor and Sonja Kotz (University of Manchester; Lancaster University; Maastricht University, Netherlands)
Embodied cognition theories propose that language processing may rely on the same modal systems for perception and action [1]. Speech perception relies on theta-band (4-7Hz) neural oscillations for segmenting and coding continuous speech signals into hierarchical linguistic units for comprehension [2,3]. Does this theta-band oscillatory mechanism also govern mental simulation of speech (inner speech) during silent reading of direct quotations? In an EEG experiment, thirty-two native speakers of English silently read 120 short stories that contained either a direct speech (e.g., Mary said: “This dress is lovely”) or an indirect speech (e.g., Mary said that the dress was lovely) for comprehension. Their EEG data were pre-processed and epoched to the onsets of the speech quotations, followed by time-frequency decomposition. In the theta frequency band (4-7 Hz), we observed significantly higher phase-locking value (i.e. inter-trial phase coherence) in the right temporal sensors at ~200-400ms when reading direct (relative to indirect) speech quotations. This reflects a phase reset at the start of inner speech processing, similar to that at the onset of speech perception [4,5]. The phase reset was source-localised to the right posterior superior temporal sulcus – areas that are linked to prosodic processing of speech in perception [6]. In line with the embodied cognition framework, our results demonstrate that mental simulation of speech may engage the same theta-band oscillatory mechanism for perception of actual speech.
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- Ding, N., Melloni, L., Zhang, H., Tian, X., & Poeppel, D. (2015). Cortical tracking of hierarchical linguistic structures in connected speech. Nature Neuroscience, 19(1), 158–164;
- Peelle, J. E., Gross, J., & Davis, M. H. (2013). Phase-locked responses to speech in human auditory cortex are enhanced during comprehension. Cerebral Cortex, 23(6), 1378–1387;
- Giraud, A. L., & Poeppel, D. (2012). Cortical oscillations and speech processing: Emerging computational principles and operations. Nature Neuroscience, 15(4), 511–517;
- Luo, H., & Poeppel, D. (2007). Phase Patterns of Neuronal Responses Reliably Discriminate Speech in Human Auditory Cortex. Neuron, 54(6), 1001–1010;
- Belin, P., Fecteau, S., & Bedard, C. (2004). Thinking the voice: neural correlates of voice perception. Trends in Cognitive Sciences, 8(3), 129–135.
40) Visual tone facilitates the early auditory tone processing: Evidence from N1 and P2
Rui Wang, Xun He and Biao Zeng (Bournemouth University; University of South Wales)
Salient visual feature facilitates to predict the corresponding auditory speech signal, hence leading to a greater audiovisual (AV) reduction effect in N1/P2 latency (van Wanssenhove, Grant & Poeppel, 2005). The current study investigated whether such AV reduction occurred to Mandarin lexical tone. For lexical tones, the visual feature is less salient than the one in consonants, e.g. mouth shape or lip movement. Based on this, the AV reduction effect should be smaller in lexical tone response compared the one in consonant response. Same-different discrimination paradigm was used in the study. Participates were asked to judge whether two sequential stimuli were same or different for their auditory information. The two sequential stimuli were played in three conditions; 1) auditory-only and audio-only; 2) auditory-only and audiovisual; 3) auditory-only and visual-only. Twenty participants (aged 25.75 ± 4.4 years; female: 13) participated in the lexical tone experiment, and 19 participants (aged: 26.58 ± 5.69 years; female: 11) took part in the consonant experiment. The results showed a few major electrophysiological features of AV lexical tone integration. First, the auditory processing of lexical tones was suppressed and was accelerated by visual tone input starting from the auditory N1 time range, which further supports the AV benefit effect on lexical tones. Second, AV lexical tone integration maximised later than AV consonant integration and lasted longer (over N1 to P2). Third, lexical tone interaction processing showed more right-lateralised activation.
- Van Wassenhove, V., Grant, K. W., & Poeppel, D. (2005). Visual speech speeds up the neural processing of auditory speech. Proceedings of the National Academy of Sciences of the United States of America, 102(4), 1181–1186. http://doi.org/10.1073/pnas.0408949102
41) Primacy of mouth than eyes to perceive audiovisual mandarin lexical tones
Biao Zeng, Guoxing Yu and Nabil Hasshim (University of South Wales; University of Bristol; Bourenmouth University)
This study investigated Chinese and English speaker’s patterns of eye movement when they were asked to identify audiovisual Mandarin lexical tones. The Chinese and English speakers were presented a clip of Mandarin monosyllable (/ă/, /à/, /ĭ/, /ì/) in audiovisual mode and asked to identify whether the syllable was a dipping tone (/ă/, / ĭ/) or a falling tone (/ à/, /ì/). These audiovisual syllables were presented in clear, noisy and silent conditions. An eye-tracker recorded the participants’ eye movement. It was found that the participants gazed more at mouth than eyes and the mouth took more than 40% gaze duration at average. In addition, when the auditory information descended through three acoustic conditions, both Chinese and English speakers increased the gaze duration at mouth rather than eyes. The findings suggest, for audiovisual lexical tone, mouth is the primary area, not eyes. The similar eye movement patterns between Chinese and English speakers implies that mouth might play a perceptual cue relevant to articulatory than semantic information.
42) Impaired visual-object recognition in people with dyslexia: An ERP study of perceptual closure
Janusz Zielinski, Angela Gosling, Elley Wakui and Mary-Jane Budd (University of East London)
Developmental Dyslexia is a language disorder which manifests itself in the inability to learn to read adequately when IQ and vision are normal. Problems in reading and writing and phonological processing shown by Developmental Dyslexics may lie in poor visual coding from a deficit in the visual dorsal stream [1]. One approach to studying visual processing is object recognition and perceptual closure. This refers to filling in missing information by the visual system to presented images. Images were presented using different spatial frequencies from a blurred image to a clear image and were presented successively (less blurred until recognized). An Event Related Potential (ERP) called the closure negativity Ncl can be measured with each successive presentation of the image. The Ncl increases until the image is recognised and then the Ncl becomes stable. The Ncl of Dyslexics and non-dyslexics were compared, along with the preceeding P1 component, an indicator of dorsal stream neural activity, and the N1, an indicator of ventral stream processing. Differences were found in both the Ncl and the P1, with a qualitative difference between the two groups showing in the Ncl indicating perhaps different neural generators whereas, the P1 showed a more enhanced amplitude for the non-dyslexics (a quantitative difference). These differences in the visual processing of objects in dyslexics are discussed with how this may disrupt the visual input required for reading
- Vidyasagar, T. R., & Pammer, K. (2010). Dyslexia: a deficit in visuo-spatial attention, not in phonological processing. Trends in cognitive sciences, 14(2), 57-63.
43) Alterations of cortical thickness and global myelin over the primary sensory cortices
in a sample at ultra-high risk for psychosis
Aikaterini Zikidi, Alessio Fracasso and Peter J. Uhlhaas (Carl von Ossietzky University of Oldenburg; University of Glasgow)
Previous research reported a loss of cortical thickness throughout cortical and subcortical areas in schizophrenia (Scz). One of the most prominent findings is the disproportionate supra-granular thinning in comparison to the infragranular compartments [1,2]. One functional consequence could be an impairment in feed-forward processing due to the role of superficial layers in the propagation of incoming sensory information [3,4]. First findings by Wagstyl and his colleagues [5] have highlighted a steeper thinning gradient along the sensory hierarchies in Scz- patients, especially in visual areas. However, it is currently unclear whether such abnormalities exist at illness-onset. Methods: To address this issue, we recruited 202 participants, in 4 groups: ultra-high risk (UHR) for psychosis (n =105), first episode (FEP) psychosis (n = 13), substance abuse and affective disorders (n = 34) and healthy controls (n = 50 ). Participants were characterized through neuropsychological and psychiatric assessments. High resolution T1 scans were acquired and analysed in terms of (a) GM density over the whole cortex, (b) myelination density over the primary sensory cortices and (c) differences in myelination levels across cortical depth. Results: Pronounced cortical thinning was observed in sensory areas in FEP- and UHR- groups compared to controls, specifically in auditory and visual cortices. Moreover, we detected a coupling between thinning and lower myelination levels (measured via T1-w intensity) along the sensory hierarchies. Discussion: Acquiring further insights into myelin-related neuroanatomical changes that are traceable through MRi scans, will enable us to unveil anatomical links between the emerging deficits of cognitive and sensory processes in schizophrenia and alterations over the sensory hierarchies that are present prior to the full manifestation of the disorder.
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- Charvet, C. J., Cahalane, D. J. & Finlay, B. L. (2013). Systematic, cross-cortex variation in neuron numbers in rodents and primates. Cerebral Cortex, 25(1), 147-160.
- Wagstyl, K., Ronan, L., Goodyer, I. M. & Fletcher, P. C. (2015). Cortical thickness gradients in structural hierarchies. Neuroimage, 111, 241-250.
- Wagstyl, K., Ronan, L., Whitaker, J. K., Goodyer, I. M., Roberts, N., Crow, T. J. & Fletcher, P. C. (2016). Multiple markers of cortical morphology reveal evidence of supragranular thinning in schizophrenia. Translational Psychiatry, 1-7.
44) Functional network correlates of lack of control and impulsivity in healthy young adults
Andras N. Zsido, Szabolcs Bandi, Orsolya Inhof, Beatrix Labadi, Nikolett Arato, Timea Budai, Gabor Perlaki, Gergely Orsi, Norbert Kovacs, Tamas Doczi, Jozsef Janszky and Gergely Darnai (University of Pécs, Hungary)
Understanding which brain regions engaged in response inhibition and impulsivity control provides insight into the underlying mechanisms of behavioural addictions. Research on internet addiction, in particular, draws more and more attention due to the novelty of the field and the growing prevalence. Furthermore, due to a hiatus in clinical practice to help the recovery of those suffering in internet addiction. We used the Stroop-task and a nonverbal Stroop-like task to assess inhibitory ability, while measuring task-related fMRI responses in 60 young adults. The Motor Impulsivity subscale of the Barratt Impulsiveness Scale and the Control disorder subscale of the Problematic Internet Use Questionnaire was used to measure impaired control functions and impulsivity. We reduced the dimensionality of the fMRI data set using independent component analysis, and then examined correlations between questionnaires and the resulting component scores. The analyses yielded 36 independent components. We excluded 14 based on visual checking. The remaining 22 components were correlated with the two questionnaires separately. Three components (5, 7, 9) correlated significantly with both questionnaires after controlling for multiple comparisons. Component 5 included key regions associated with response inhibition, including the Supplementary Moor Area, Superior Frontal Gyrus, paracingulate, insular cortex; and regions associated with the default mode network, such as praecuneus, postcentral and medial frontal gyrus. Component 7 included similar areas without the SMA, but also precentral gyrus and opercular and frontal orbital cortices. Component 9 was again similar to Component 5 but including the pre- and postcentral gyri. The relationships between brain activation and questionnaire scores suggest multiple possible mechanism on how excessive internet use may influence brain functions.