Ineffective participant blinding during 1mA transcranial direct current stimulation
Larissa Buhôt, Robert Greinacher, Lisa Möller and Gemma Learmonth (University of Glasgow, University of Lübeck, Germany)
Many studies involving transcranial direct current stimulation (tDCS) include a “sham” (placebo) condition, with which performance during the “active” tDCS condition is compared. Sham tDCS usually involves only a few seconds of stimulation, and is assumed to be perceptually indistinct from active tDCS on the scalp. For this reason, tDCS is claimed to be an effective means of delivering double-blinded brain stimulation protocols. However, participants often show above-chance accuracy when asked retrospectively which condition involved sham. Here, we aimed to probe in real-time the effectiveness of tDCS blinding during a reaction time experiment. 33 adults were tested (pre-registered a priori sample size: d=0.45, α=0.05, power=0.8). A simple, forced-choice reaction time task was undertaken before, during and after active (10min of 1mA) and sham tDCS (20s of 1mA; both with 30s ramp-up/down). Conditions were applied on different days in a counterbalanced, double-blinded, within-subjects design. The anode was placed vertically over the left primary motor cortex (C3) to target the right hand, with the return on the right forehead. For 15min after the tDCS was initiated, 2 probe questions were interspersed within the task at 30s intervals (“Is the stimulation on?” & “How sure are you?”). Active tDCS had no effect on reaction times compared to sham. Weighted responses were calculated for the probe questions, combining the yes/no guesses with confidence ratings. 95% confidence intervals were largely distinct between the anodal and sham conditions. The period of difference began after the sham protocol had ended and lasted until the active stimulation had ramped down. These results add to the recent literature reporting either small, or no, overall behavioural effects of tDCS. In addition, participants were clearly able to differentiate the active and sham conditions throughout the experiment, suggesting that this method of blinding tDCS experiments may be ineffective.
Age-related increases in PFC activity in LTM and STM tasks are nonspecific rather than compensatory
Alexa M. Morcom and Richard N. A. Henson (University of Edinburgh; MRC Cognition and Brain Sciences Unit; University of Cambridge)
Despite declines in memory and other cognitive functions, prefrontal cortex (PFC) activity is often increased in healthy older people. This activity has been proposed to reflect a compensatory functional posterior-to-anterior shift in which greater reliance on PFC contributes to maintenance of cognitive performance as posterior cortical function is impaired. Alternatively, the additional prefrontal activity may be less specific or less efficient than in young people, due to loss of neuronal and structural integrity. It is difficult to adjudicate between these theories by measuring activity levels within brain regions. We applied a novel model-based multivariate analysis approach to two functional magnetic resonance imaging datasets from visual long-term memory (LTM) and short-term memory (STM) tasks. Participants (N=123 and N=115, 18-88 years) were independent subsets of an adult-lifespan human sample. Activation analysis replicated an age-related increase in mean prefrontal activity in both tasks, but multivariate decoding tests showed that this activity did not carry additional information relative to posterior visual cortex. Instead, both anterior and posterior regions carried less information about the cognitive tasks. The results provide direct evidence against a compensatory posterior-to-anterior shift, and suggest that elevated PFC activity in older people reflects less specific or less efficient responses rather than compensation.
Age-mediated parietal contribution to salience based selection
Carmel Mevorach, Brandon K. Ashinoff and Stephen Mayhew (University of Birmingham)
Cognitive aging has been associated with a decline in inhibitory processes. Older participants seem to be less capable at inhibiting distractors, especially when they are more salient than targets. While various neuronal changes have also been documented as a function of age the underlying brain mechanisms that mediate this behavioural change are still poorly understood. Interestingly, there is a striking similarity between old participants’ performance in a salience-suppression task [1] and the effect of inhibitory brain stimulation over the left IPS in young participants performing the same task [2]. Furthermore, the left IPS contribution in young participants appears to be proactive - in anticipation of the impending stimuli. Proactive control is thought to be specifically impaired in old age, where a shift toward reactive control (a late-correction mechanism) has been observed [3]. To assess whether brain activation patterns in old age fit with this idea of shift from proactive to reactive control, we recorded brain activation using fMRI in two groups of old and young adult participants while they performed a salience-based suppression task. Specifically we ask whether activations in left IPS or left TPJ (previously linked to reactive control in young adults) are mediated by age. Our results show a qualitative difference in brain activation in the two groups when salient distractors had to be ignored (which is apparent even when global differences in cerebral blood flow between the groups are controlled for). While both groups show left IPS activation, the older participants seem to rely on additional activation in the left TPJ (as well as left IFG). We argue that this left lateralized parietal activation is associated with a reactive inhibition network that is most likely engaged in old age to overcome an initial capture by the salient distractors.
Meeting expectations: Transient cross-frequency EEG phase synchronisation as neural signature of matching mental templates to sensory input
Paul Sauseng, Charline Peylo and Anna Lena Biel (Ludwig-Maximilians-University Munich)
Where‘s Wally? To find him you need a mental representation (template) of Wally in memory which you will then match to incoming (visual) information. It has been shown before that by transiently synchronising the phase of slow oscillatory brain activity (theta) and fast rhythmical activity (gamma) the brain achieves matching between expectation (template) and incoming information. Here, we investigated (i) how mental templates are established in memory over time and how the fidelity of these mental templates impacts on matching with sensory input and theta-gamma-phase-synchronisation; and we studied (ii) how template-to-input matching is influenced by memory load. In two EEG experiments we tested young, healthy participants. In the first experiment strings of abstract symbols were matched to visual targets, and supported by trial to trial feedback participants had to learn which symbol string was paired with which target. In a second experiment, participants had to identify one of three or only a single target in a visual search task. In both studies posterior theta-gamma phase synchronisation was examined. In experiment 1 we found individual learning-dependent increase of theta-gamma phase synchronisation in posterior parietal cortex to be positively correlated with template fidelity in memory. Experiment 2 shows theta-gamma phase synchronisation in parietal cortex to be stronger when only one mental template is held in working memory and matched with incoming information compared to three templates in memory. Here, we have provided evidence that template-input matching indeed seems to be manifested by theta-gamma phase synchronisation, and that this neural correlate is modulated by template fidelity and memory load during visual perceptual and attentional tasks.
The macaque anterior cingulate cortex translates counterfactual choice value into actual behavioral change
Elsa Fouragnan, Bolton K.H. Chau, Davide Folloni, Nils Kolling, Lennart Verhagen, Miriam Klein-Flugge, Lev Tankelevitch, Georgios K. Papageorgiou, Jean-Francois Aubry, Jerome Sallet and Matthew F.S. Rushworth (University of Oxford; University of Plymouth; The Hong Kong Polytechnic University, Hong Kong; Massachusetts Institute of Technology, USA; INSERM U979, PSL Research University, France)
The neural mechanisms mediating sensory-guided decision making have received considerable attention but animals often pursue behaviors for which there is currently no sensory evidence. Such behaviors are guided by internal representations of choice values that have to be maintained even when these choices are unavailable [1]. We investigated how four macaque monkeys maintained representations of the value of counterfactual choices: choices that could not be taken at the current moment but which could be taken in the future. Using functional magnetic resonance imaging (fMRI) , we found two different patterns of activity co-varying with values of counterfactual choices in a circuit spanning hippocampus, anterior lateral prefrontal cortex, and anterior cingulate cortex (ACC). ACC activity also reflected whether the internal value representations would be translated into actual behavioral change. To establish the causal importance of ACC for this translation process, we used a novel technique, Transcranial Focused Ultrasound Stimulation, to reversibly disrupt ACC activity [2]. The spatially focal effect of TUS was further confirmed by examining functional connectivity patterns between activity in the ACC and in the rest of the brain using resting-state fMRI [3].
Neural and computational principles of active multi-sensing and decision-making
Ioannis Delis, Robin A.A. Ince, Paul Sajda and Qi Wang (University of Leeds; University of Glasgow; Columbia University, USA)
Perceptual decisions rely on the integration of information from the environment involving stimuli from different senses. The quality of sensory information depends on our actions, which affect how we sample evidence, a process referred to as active sensing. However, the neural mechanisms underlying this complex human behaviour remain elusive. Here, we employed a novel active sensing paradigm [1] coupled with state-of-the-art neuroimaging and computational modelling to probe how the brain processes multisensory information to make fast and accurate decisions. We devised a reaction-time task where human subjects actively sensed and discriminated the amplitude of two texture stimuli a) using only visual information, b) using only haptic information and c) combining the two sensory cues, while electroencephalograms (EEG) were recorded. To quantify interactions between EEG signals and active sensory experience, we developed a novel multivariate correlation analysis, which yielded components of brain-behaviour entrainment. To probe the functional role of each component in decision formation, we informed a hierarchical drift diffusion model (HDDM) with the single-trial brain-behaviour couplings. This neurobiologically-informed HDDM provided a mechanistic account of the constituent processes as well as their modulation by the underlying brain networks. We found that the LOC modulated the stimulus encoding whereas the MFG predicted the rate of information integration towards a choice [2]. Then, we used an information-theoretic methodology to quantify the contribution of each sensory modality – and of their interaction - to the perception of the stimulus [3]. We identified an EEG component carrying information shared between the two sensory inputs and another EEG component reflecting a synergistic representational interaction. Ultimately, this work will uncover the brain networks involved in active multi-sensing and characterize their roles in decision-making performance.
Conscious and unconscious forms of vicarious pain perception
Jamie Ward, Tom Grice-Jackson, Vanessa Botan and Hugo Critchley (University of Sussex; Brighton and Sussex Medical School)
Does seeing someone else in pain utilize any of the same neural resources as the physical experience of pain? Studies attempting to address this have revealed an inconsistent picture, and this presentation will explore one reason for this inconsistency: individual differences. Specifically, using a new measure (Vicarious Pain Questionnaire) we show that up to a quarter of the neurotypical population report conscious pain-like experiences when seeing others in pain. This is linked to functional differences in the brain (greater EEG mu suppression, more somatosensory activity in fMRI), structural differences (shown by VBM), as well as a pattern of wider cognitive differences (body ownership assessed with rubber hand illusion). Thus, there is a surprising heterogeneity in 'normal' responsiveness to seeing others in pain that has hitherto been unappreciated by the large volume of studies exploring empathy for pain.
Neural circuits supporting social and non-social inhibitory control
Kohinoor M. Darda and Richard Ramsey (Bangor University)
Humans automatically copy other’s actions building rapport and social closeness in the process. In many social situations, however, imitation can be maladaptive and requires inhibition. Prior studies have provided mixed evidence regarding the neural engagement of domain-specific (i.e. Theory-of-Mind (ToM) network) and domain-general (i.e. Multiple Demand (MD) network) circuits in imitation control. In a recent fMRI study, across two experiments with the largest sample size till date (N=28, N=50), the MD network was found to be sensitive to both imitative and spatial compatibility, but there was no engagement of the ToM network [1]. However, it is still unclear whether engagement of the MD network and the representation within the MD regions is similar or different for imitation control and a non-social control task which does not involve any social stimuli. Further, the ToM network and other domain-specific socio-perceptual circuits may play a regulatory role in imitation control, without being directly engaged. Thus, in the current experiment (N=50) we investigate the following research questions: 1. Using univariate measures, what is the pattern of response in the MD network for imitation control and a non-social control task which does not involve any social stimuli? 2. Using connectivity measures, a) do we find different patterns of functional coupling within the MD network for imitation control and a non-social control task, and b) do we find different patterns of connectivity between socio-perceptual circuits (action perception and person perception) and MD or ToM networks for the imitative and spatial compatibility effects (using social stimuli)? 3. Using multivariate analyses, are there control-specific representations in the MD network? A different representation for imitation control and non-social control would indicate that the MD network deals with social conflict differently than non-social conflict.
Larissa Buhôt, Robert Greinacher, Lisa Möller and Gemma Learmonth (University of Glasgow, University of Lübeck, Germany)
Many studies involving transcranial direct current stimulation (tDCS) include a “sham” (placebo) condition, with which performance during the “active” tDCS condition is compared. Sham tDCS usually involves only a few seconds of stimulation, and is assumed to be perceptually indistinct from active tDCS on the scalp. For this reason, tDCS is claimed to be an effective means of delivering double-blinded brain stimulation protocols. However, participants often show above-chance accuracy when asked retrospectively which condition involved sham. Here, we aimed to probe in real-time the effectiveness of tDCS blinding during a reaction time experiment. 33 adults were tested (pre-registered a priori sample size: d=0.45, α=0.05, power=0.8). A simple, forced-choice reaction time task was undertaken before, during and after active (10min of 1mA) and sham tDCS (20s of 1mA; both with 30s ramp-up/down). Conditions were applied on different days in a counterbalanced, double-blinded, within-subjects design. The anode was placed vertically over the left primary motor cortex (C3) to target the right hand, with the return on the right forehead. For 15min after the tDCS was initiated, 2 probe questions were interspersed within the task at 30s intervals (“Is the stimulation on?” & “How sure are you?”). Active tDCS had no effect on reaction times compared to sham. Weighted responses were calculated for the probe questions, combining the yes/no guesses with confidence ratings. 95% confidence intervals were largely distinct between the anodal and sham conditions. The period of difference began after the sham protocol had ended and lasted until the active stimulation had ramped down. These results add to the recent literature reporting either small, or no, overall behavioural effects of tDCS. In addition, participants were clearly able to differentiate the active and sham conditions throughout the experiment, suggesting that this method of blinding tDCS experiments may be ineffective.
Age-related increases in PFC activity in LTM and STM tasks are nonspecific rather than compensatory
Alexa M. Morcom and Richard N. A. Henson (University of Edinburgh; MRC Cognition and Brain Sciences Unit; University of Cambridge)
Despite declines in memory and other cognitive functions, prefrontal cortex (PFC) activity is often increased in healthy older people. This activity has been proposed to reflect a compensatory functional posterior-to-anterior shift in which greater reliance on PFC contributes to maintenance of cognitive performance as posterior cortical function is impaired. Alternatively, the additional prefrontal activity may be less specific or less efficient than in young people, due to loss of neuronal and structural integrity. It is difficult to adjudicate between these theories by measuring activity levels within brain regions. We applied a novel model-based multivariate analysis approach to two functional magnetic resonance imaging datasets from visual long-term memory (LTM) and short-term memory (STM) tasks. Participants (N=123 and N=115, 18-88 years) were independent subsets of an adult-lifespan human sample. Activation analysis replicated an age-related increase in mean prefrontal activity in both tasks, but multivariate decoding tests showed that this activity did not carry additional information relative to posterior visual cortex. Instead, both anterior and posterior regions carried less information about the cognitive tasks. The results provide direct evidence against a compensatory posterior-to-anterior shift, and suggest that elevated PFC activity in older people reflects less specific or less efficient responses rather than compensation.
Age-mediated parietal contribution to salience based selection
Carmel Mevorach, Brandon K. Ashinoff and Stephen Mayhew (University of Birmingham)
Cognitive aging has been associated with a decline in inhibitory processes. Older participants seem to be less capable at inhibiting distractors, especially when they are more salient than targets. While various neuronal changes have also been documented as a function of age the underlying brain mechanisms that mediate this behavioural change are still poorly understood. Interestingly, there is a striking similarity between old participants’ performance in a salience-suppression task [1] and the effect of inhibitory brain stimulation over the left IPS in young participants performing the same task [2]. Furthermore, the left IPS contribution in young participants appears to be proactive - in anticipation of the impending stimuli. Proactive control is thought to be specifically impaired in old age, where a shift toward reactive control (a late-correction mechanism) has been observed [3]. To assess whether brain activation patterns in old age fit with this idea of shift from proactive to reactive control, we recorded brain activation using fMRI in two groups of old and young adult participants while they performed a salience-based suppression task. Specifically we ask whether activations in left IPS or left TPJ (previously linked to reactive control in young adults) are mediated by age. Our results show a qualitative difference in brain activation in the two groups when salient distractors had to be ignored (which is apparent even when global differences in cerebral blood flow between the groups are controlled for). While both groups show left IPS activation, the older participants seem to rely on additional activation in the left TPJ (as well as left IFG). We argue that this left lateralized parietal activation is associated with a reactive inhibition network that is most likely engaged in old age to overcome an initial capture by the salient distractors.
- Tsvetanov, K., Mevorach, C., Allen, H., & Humphreys, G.W., (2013) Age-related differences in Selection by Visual Saliency. Attention, Perception & Psychophysics, 75 (7), 1382-1394.
- Mevorach, C., Humphreys, G. W. & Shalev, L. (2009). Reflexive and preparatory selection and suppression of saliency in the right and left posterior parietal cortex. Journal of Cognitive Neuroscience, 21:6, 1204-1214
- Braver, S.T., (2012). The variable nature of cognitive control: a dual mechanisms framework. Trends in Cognitive Sciences, 16(2), 106-113
Meeting expectations: Transient cross-frequency EEG phase synchronisation as neural signature of matching mental templates to sensory input
Paul Sauseng, Charline Peylo and Anna Lena Biel (Ludwig-Maximilians-University Munich)
Where‘s Wally? To find him you need a mental representation (template) of Wally in memory which you will then match to incoming (visual) information. It has been shown before that by transiently synchronising the phase of slow oscillatory brain activity (theta) and fast rhythmical activity (gamma) the brain achieves matching between expectation (template) and incoming information. Here, we investigated (i) how mental templates are established in memory over time and how the fidelity of these mental templates impacts on matching with sensory input and theta-gamma-phase-synchronisation; and we studied (ii) how template-to-input matching is influenced by memory load. In two EEG experiments we tested young, healthy participants. In the first experiment strings of abstract symbols were matched to visual targets, and supported by trial to trial feedback participants had to learn which symbol string was paired with which target. In a second experiment, participants had to identify one of three or only a single target in a visual search task. In both studies posterior theta-gamma phase synchronisation was examined. In experiment 1 we found individual learning-dependent increase of theta-gamma phase synchronisation in posterior parietal cortex to be positively correlated with template fidelity in memory. Experiment 2 shows theta-gamma phase synchronisation in parietal cortex to be stronger when only one mental template is held in working memory and matched with incoming information compared to three templates in memory. Here, we have provided evidence that template-input matching indeed seems to be manifested by theta-gamma phase synchronisation, and that this neural correlate is modulated by template fidelity and memory load during visual perceptual and attentional tasks.
The macaque anterior cingulate cortex translates counterfactual choice value into actual behavioral change
Elsa Fouragnan, Bolton K.H. Chau, Davide Folloni, Nils Kolling, Lennart Verhagen, Miriam Klein-Flugge, Lev Tankelevitch, Georgios K. Papageorgiou, Jean-Francois Aubry, Jerome Sallet and Matthew F.S. Rushworth (University of Oxford; University of Plymouth; The Hong Kong Polytechnic University, Hong Kong; Massachusetts Institute of Technology, USA; INSERM U979, PSL Research University, France)
The neural mechanisms mediating sensory-guided decision making have received considerable attention but animals often pursue behaviors for which there is currently no sensory evidence. Such behaviors are guided by internal representations of choice values that have to be maintained even when these choices are unavailable [1]. We investigated how four macaque monkeys maintained representations of the value of counterfactual choices: choices that could not be taken at the current moment but which could be taken in the future. Using functional magnetic resonance imaging (fMRI) , we found two different patterns of activity co-varying with values of counterfactual choices in a circuit spanning hippocampus, anterior lateral prefrontal cortex, and anterior cingulate cortex (ACC). ACC activity also reflected whether the internal value representations would be translated into actual behavioral change. To establish the causal importance of ACC for this translation process, we used a novel technique, Transcranial Focused Ultrasound Stimulation, to reversibly disrupt ACC activity [2]. The spatially focal effect of TUS was further confirmed by examining functional connectivity patterns between activity in the ACC and in the rest of the brain using resting-state fMRI [3].
- Boorman, E. D., Behrens, T. E. J., Woolrich, M. W. & Rushworth, M. F. S. How green is the grass on the other side? Frontopolar cortex and the evidence in favor of alternative courses of action. Neuron 62, 733–743 (2009).
- Fouragnan, E. F. et al. The macaque anterior cingulate cortex translates counterfactual choice value into actual behavioral change. bioRxiv 336917 (2018). doi:10.1101/336917
- Folloni, D. et al. Manipulation of deep brain activity in primates using transcranial focused ultrasound stimulation. bioRxiv 342303 (2018). doi:10.1101/342303
Neural and computational principles of active multi-sensing and decision-making
Ioannis Delis, Robin A.A. Ince, Paul Sajda and Qi Wang (University of Leeds; University of Glasgow; Columbia University, USA)
Perceptual decisions rely on the integration of information from the environment involving stimuli from different senses. The quality of sensory information depends on our actions, which affect how we sample evidence, a process referred to as active sensing. However, the neural mechanisms underlying this complex human behaviour remain elusive. Here, we employed a novel active sensing paradigm [1] coupled with state-of-the-art neuroimaging and computational modelling to probe how the brain processes multisensory information to make fast and accurate decisions. We devised a reaction-time task where human subjects actively sensed and discriminated the amplitude of two texture stimuli a) using only visual information, b) using only haptic information and c) combining the two sensory cues, while electroencephalograms (EEG) were recorded. To quantify interactions between EEG signals and active sensory experience, we developed a novel multivariate correlation analysis, which yielded components of brain-behaviour entrainment. To probe the functional role of each component in decision formation, we informed a hierarchical drift diffusion model (HDDM) with the single-trial brain-behaviour couplings. This neurobiologically-informed HDDM provided a mechanistic account of the constituent processes as well as their modulation by the underlying brain networks. We found that the LOC modulated the stimulus encoding whereas the MFG predicted the rate of information integration towards a choice [2]. Then, we used an information-theoretic methodology to quantify the contribution of each sensory modality – and of their interaction - to the perception of the stimulus [3]. We identified an EEG component carrying information shared between the two sensory inputs and another EEG component reflecting a synergistic representational interaction. Ultimately, this work will uncover the brain networks involved in active multi-sensing and characterize their roles in decision-making performance.
- Campion G, Wang Q, Hayward V (2005), “The Pantograph Mk-II: A haptic instrument”. Ieee/Rsj International Conference on Intelligent Robots and Systems, Vols 1-4:723-728.
- Delis I, Dmochowski JP, Sajda P, & Wang Q (2018), “Correlation of Neural Activity with Behavioral Kinematics Reveals Distinct Sensory Encoding and Evidence Accumulation Processes During Active Tactile Sensing.” NeuroImage, 175:12-21.
- Ince RAA, Giordano BL, Kayser C, Rousselet GA, Gross J, & Schyns PG. (2017). “A Statistical Framework for Neuroimaging Data Analysis Based on Mutual Information Estimated via a Gaussian Copula.” Human Brain Mapping 38, no. 3: 1541–73.
Conscious and unconscious forms of vicarious pain perception
Jamie Ward, Tom Grice-Jackson, Vanessa Botan and Hugo Critchley (University of Sussex; Brighton and Sussex Medical School)
Does seeing someone else in pain utilize any of the same neural resources as the physical experience of pain? Studies attempting to address this have revealed an inconsistent picture, and this presentation will explore one reason for this inconsistency: individual differences. Specifically, using a new measure (Vicarious Pain Questionnaire) we show that up to a quarter of the neurotypical population report conscious pain-like experiences when seeing others in pain. This is linked to functional differences in the brain (greater EEG mu suppression, more somatosensory activity in fMRI), structural differences (shown by VBM), as well as a pattern of wider cognitive differences (body ownership assessed with rubber hand illusion). Thus, there is a surprising heterogeneity in 'normal' responsiveness to seeing others in pain that has hitherto been unappreciated by the large volume of studies exploring empathy for pain.
Neural circuits supporting social and non-social inhibitory control
Kohinoor M. Darda and Richard Ramsey (Bangor University)
Humans automatically copy other’s actions building rapport and social closeness in the process. In many social situations, however, imitation can be maladaptive and requires inhibition. Prior studies have provided mixed evidence regarding the neural engagement of domain-specific (i.e. Theory-of-Mind (ToM) network) and domain-general (i.e. Multiple Demand (MD) network) circuits in imitation control. In a recent fMRI study, across two experiments with the largest sample size till date (N=28, N=50), the MD network was found to be sensitive to both imitative and spatial compatibility, but there was no engagement of the ToM network [1]. However, it is still unclear whether engagement of the MD network and the representation within the MD regions is similar or different for imitation control and a non-social control task which does not involve any social stimuli. Further, the ToM network and other domain-specific socio-perceptual circuits may play a regulatory role in imitation control, without being directly engaged. Thus, in the current experiment (N=50) we investigate the following research questions: 1. Using univariate measures, what is the pattern of response in the MD network for imitation control and a non-social control task which does not involve any social stimuli? 2. Using connectivity measures, a) do we find different patterns of functional coupling within the MD network for imitation control and a non-social control task, and b) do we find different patterns of connectivity between socio-perceptual circuits (action perception and person perception) and MD or ToM networks for the imitative and spatial compatibility effects (using social stimuli)? 3. Using multivariate analyses, are there control-specific representations in the MD network? A different representation for imitation control and non-social control would indicate that the MD network deals with social conflict differently than non-social conflict.
- Darda, K. M., Butler, E. E., & Ramsey, R. (2018). Functional Specificity and Sex Differences in the Neural Circuits Supporting the Inhibition of Automatic Imitation. Journal of cognitive neuroscience, 30(6), 914-933.