Two takes on the social brain: a comparison of theory of mind tasks

We compared two tasks that are widely used in research on mentalizing--false belief stories and animations of rigid geometric shapes that depict social interactions--to investigate whether the neural systems that mediate the representation of others' mental states are consistent across these tasks. Whereas false belief stories activated primarily the anterior paracingulate cortex (APC), the posterior cingulate cortex/precuneus (PCC/PC), and the temporo-parietal junction (TPJ)--components of the distributed neural system for theory of mind (ToM)--the social animations activated an extensive region along nearly the full extent of the superior temporal sulcus, including a locus in the posterior superior temporal sulcus (pSTS), as well as the frontal operculum and inferior parietal lobule (IPL)--components of the distributed neural system for action understanding--and the fusiform gyrus. These results suggest that the representation of covert mental states that may predict behavior and the representation of intentions that are implied by perceived actions involve distinct neural systems. These results show that the TPJ and the pSTS play dissociable roles in mentalizing and are parts of different distributed neural systems. Because the social animations do not depict articulated body movements, these results also highlight that the perception of the kinematics of actions is not necessary to activate the mirror neuron system, suggesting that this system plays a general role in the representation of intentions and goals of actions. Furthermore, these results suggest that the fusiform gyrus plays a general role in the representation of visual stimuli that signify agency, independent of visual form.     

Affective and cooperative social interactions modulate effective connectivity within and between the mirror and mentalizing systems

Decoding the meaning of others’ actions, a crucial step for social cognition, involves different neural mechanisms. While the “mirror” and “mentalizing” systems have been associated with, respectively, the processing of biological actions versus more abstract information, their respective contribution to intention understanding is debated. Processing social interactions seems to recruit both neural systems, with a different weight depending on cues emphasizing either shared action goals or shared mental states. We have previously shown that observing cooperative and affective social interactions elicits stronger activity in key nodes of, respectively, the mirror (left posterior superior temporal sulcus (pSTS), superior parietal cortex (SPL), and ventral/dorsal premotor cortex (vPMC/dPMC)) and mentalizing (ventromedial prefrontal cortex (vmPFC)) systems. To unveil their causal organization, we investigated the effective connectivity underlying the observation of human social interactions expressing increasing cooperativity (involving left pSTS, SPL, and vPMC) versus affectivity (vmPFC) via dynamic causal modeling in 36 healthy human subjects. We found strong evidence for a model including the pSTS and vPMC as input nodes for the observed interactions. The extrinsic connectivity of this model undergoes oppositely valenced modulations, with cooperativity promoting positive modulations of connectivity between pSTS and both SPL (forward) and vPMC (mainly backward), and affectivity promoting reciprocal positive modulations of connectivity between pSTS and vmPFC (mainly backward). Alongside fMRI data, such divergent effective connectivity suggests that different dimensions underlying the processing of social interactions recruit distinct, although strongly interconnected, neural pathways associated with, respectively, the bottom–up visuomotor processing of motor intentions, and the top–down attribution of affective/mental states.     

Association of trait emotional intelligence and individual fMRI‐activation patterns during the perception of social signals from voice and face

Multimodal integration of nonverbal social signals is essential for successful social interaction. Previous studies have implicated the posterior superior temporal sulcus (pSTS) in the perception of social signals such as nonverbal emotional signals as well as in social cognitive functions like mentalizing/theory of mind. In the present study, we evaluated the relationships between trait emotional intelligence (EI) and fMRI activation patterns in individual subjects during the multimodal perception of nonverbal emotional signals from voice and face. Trait EI was linked to hemodynamic responses in the right pSTS, an area which also exhibits a distinct sensitivity to human voices and faces. Within all other regions known to subserve the perceptual audiovisual integration of human social signals (i.e., amygdala, fusiform gyrus, thalamus), no such linked responses were observed. This functional difference in the network for the audiovisual perception of human social signals indicates a specific contribution of the pSTS as a possible interface between the perception of social information and social cognition. Hum Brain Mapp, 2010. © 2009 Wiley‐Liss, Inc.     

Schizophrenia and Autism as Contrasting Minds: Neural Evidence for the Hypo-Hyper-Intentionality Hypothesis

Both schizophrenia (SCZ) and autism spectrum disorder (ASD) are characterized by mentalizing problems and associated neural dysfunction of the social brain. However, the deficits in mental state attribution are somehow opposed: Whereas patients with SCZ tend to over-attribute intentions to agents and physical events (“hyper-intentionality”), patients with autism treat people as devoid of intentions (“hypo-intentionality”). Here we aimed to investigate whether this hypo-hyper-intentionality hypothesis can be supported by neural evidence during a mentalizing task. Using functional magnetic resonance imaging (fMRI), we investigated the neural responses and functional connectivity during reading others intention. Scanning was performed in 23 individuals with ASD, 18 with paranoid SCZ and 23 gender and IQ matched control subjects. Both clinical groups showed reduced brain activation compared to controls for the contrast intentional vs physical information processing in left posterior superior temporal sulcus (pSTS) and ventral medial prefrontal cortex (vMPFC) for SCZ, and right pSTS in ASD. As predicted, these effects were caused in a group specific way: Relative increased activation for physical information processing in SCZ that was also correlated with positive PANNS score and relative decreased activation for intentional information processing in ASD. Additionally, we could demonstrate opposed connectivity patterns between the right pSTS and vMPFC in the clinical groups, ie, increased for SCZ, decreased for ASD. These findings represent opposed neural signatures in key regions of the social brain as predicted by the hyper-hypo-intentionality hypothesis.     

Neocerebellar contributions to social perception in adolescents with autism spectrum disorder

Posterior superior temporal sulcus (pSTS) is specialized for interpreting perceived human actions, and disruptions to its function occur in autism spectrum disorder (ASD). Here we consider the role of Crus I of neocerebellum in supporting pSTS function. Research has associated Crus I activity with imitation and biological motion perception, and neocerebellum is theorized to coordinate activity among cerebral sites more generally. Moreover, cerebellar abnormalities have been associated with ASD. We hypothesized that disordered Crus I–pSTS interactions could predict social deficits in ASD. 15 high functioning adolescents with ASD and 15 same-age comparison youth participated in an fMRI imitation paradigm; ratings of mentalizing ability were collected via parent report. We predicted that stronger Crus I–pSTS interactions would be associated with better mentalizing ability. Consistent with these hypotheses, stronger psychophysiological interactions between Crus I and right pSTS were associated with greater mentalizing ability among adolescents with ASD. Whole-brain analyses also indicated that typically developing youth recruited right inferior frontal gyrus, left pSTS, medial occipital regions, and precuneus more strongly during imitation than did youth with ASD. Overall, these results indicate that variability in neocerebellar interactions with key cortical social brain sites may help explain individual differences in social perceptual outcomes in ASD.     

Functional connectivity during a social emotion task in adolescents and in adults

In this fMRI study we investigated functional connectivity between components of the mentalising system during a social emotion task, using psychophysiological interaction (PPI) analysis. Ten adults (22–32 years) and 18 adolescents (11–18 years) were scanned while thinking about scenarios in which a social or a basic emotion would be experienced. Unlike basic emotions (such as disgust and fear), social emotions (such as embarrassment and guilt) require the representation of another's mental states. In both adults and adolescents, an anterior rostral region of medial prefrontal cortex (arMPFC) involved in mentalising showed greater connectivity with the posterior superior temporal sulcus (pSTS) bordering on the temporo-parietal junction (TPJ) and with anterior temporal cortex (ATC) during social than during basic emotion. This result provides novel evidence that components of the mentalising system interact functionally during a social emotion task. Furthermore, functional connectivity differed between adolescence and adulthood. The adolescent group showed stronger connectivity between arMPFC and pSTS/TPJ during social relative to basic emotion than did the adult group, suggestive of developmental changes in functional integration within the mentalising system.     

Functional integration of the posterior superior temporal sulcus correlates with facial expression recognition

Face perception is essential for daily and social activities. Neuroimaging studies have revealed a distributed face network (FN) consisting of multiple regions that exhibit preferential responses to invariant or changeable facial information. However, our understanding about how these regions work collaboratively to facilitate facial information processing is limited. Here, we focused on changeable facial information processing, and investigated how the functional integration of the FN is related to the performance of facial expression recognition. To do so, we first defined the FN as voxels that responded more strongly to faces than objects, and then used a voxel‐based global brain connectivity method based on resting‐state fMRI to characterize the within‐network connectivity (WNC) of each voxel in the FN. By relating the WNC and performance in the “Reading the Mind in the Eyes” Test across participants, we found that individuals with stronger WNC in the right posterior superior temporal sulcus (rpSTS) were better at recognizing facial expressions. Further, the resting‐state functional connectivity (FC) between the rpSTS and right occipital face area (rOFA), early visual cortex (EVC), and bilateral STS were positively correlated with the ability of facial expression recognition, and the FCs of EVC‐pSTS and OFA‐pSTS contributed independently to facial expression recognition. In short, our study highlights the behavioral significance of intrinsic functional integration of the FN in facial expression processing, and provides evidence for the hub‐like role of the rpSTS for facial expression recognition. Hum Brain Mapp 37:1930–1940, 2016. © 2016 Wiley Periodicals, Inc.     

Engagement of amygdala in third-person view of face-to-face interaction

Humans often watch interactions between other people without taking part in the interaction themselves. Strikingly little is, however, known about how gestures and expressions of two interacting humans are processed in the observer's brain, since the study of social cues has mostly focused on the perception of solitary humans. To investigate the neural underpinnings of the third-person view of social interaction, we studied brain activations of subjects who observed two humans either facing toward or away from each other. Activations within the amygdala, posterior superior temporal sulcus (pSTS), and dorsomedial prefrontal cortex (dmPFC) were sensitive to the interactional position of the observed people and distinguished humans facing toward from humans facing away. The amygdala was most sensitive to face-to-face interaction and did not differentiate the humans facing away from the pixelated control figures, whereas the pSTS dissociated both human stimuli from the pixel figures. The results of the amygdala reactivity suggest that, in addition to regulating interpersonal distance towards oneself, the amygdala is involved in the assessment of the proximity between two other persons.     

Spontaneous mentalizing during an interactive real world task: an fMRI study

There are moments in everyday life when we need to consider the thoughts and intentions of other individuals in order to act in a socially appropriate manner. Most of this mentalizing occurs spontaneously as we go about our business in the complexity of the real world. As such, studying the neural basis of spontaneous mentalizing has been virtually impossible. Here we devised a means to achieve this by employing a unique combination of functional magnetic resonance imaging (fMRI), a detailed and interactive virtual reality simulation of a bustling familiar city, and a retrospective verbal report protocol. We were able to provide insights into the content of spontaneous mentalizing events and identify the brain regions that underlie them. We found increased activity in a number of regions, namely the right posterior superior temporal sulcus, the medial prefrontal cortex and the right temporal pole associated with spontaneous mentalizing. Furthermore, we observed the right posterior superior temporal sulcus to be consistently active during several different subtypes of mentalizing events. By contrast, medial prefrontal cortex seemed to be particularly involved in thinking about agents that were visible in the environment. Our findings show that it is possible to investigate the neural basis of mentalizing in a manner closer to its true context, the real world, opening up intriguing possibilities for making comparisons with those who have mentalizing problems.     

Neural dynamics of social tie formation in economic decision-making

The disposition for prosocial conduct, which contributes to cooperation as arising during social interaction, requires cortical network dynamics responsive to the development of social ties, or care about the interests of specific interaction partners. Here, we formulate a dynamic computational model that accurately predicted how tie formation, driven by the interaction history, influences decisions to contribute in a public good game. We used model-driven functional MRI to test the hypothesis that brain regions key to social interactions keep track of dynamics in tie strength. Activation in the medial prefrontal cortex (mPFC) and posterior cingulate cortex tracked the individual’s public good contributions. Activation in the bilateral posterior superior temporal sulcus (pSTS), and temporo-parietal junction was modulated parametrically by the dynamically developing social tie—as estimated by our model—supporting a role of these regions in social tie formation. Activity in these two regions further reflected inter-individual differences in tie persistence and sensitivity to behavior of the interaction partner. Functional connectivity between pSTS and mPFC activations indicated that the representation of social ties is integrated in the decision process. These data reveal the brain mechanisms underlying the integration of interaction dynamics into a social tie representation which in turn influenced the individual’s prosocial decisions.     

Differential involvement of the posterior temporal cortex in mentalizing but not perspective taking

Understanding and predicting other people''s mental states and behavior are important prerequisites for social interactions. The capacity to attribute mental states such as desires, thoughts or intentions to oneself or others is referred to as mentalizing. The right posterior temporal cortex at the temporal–parietal junction has been associated with mentalizing but also with taking someone else''s spatial perspective onto the world—possibly an important prerequisite for mentalizing. Here, we directly compared the neural correlates of mentalizing and perspective taking using the same stimulus material. We found significantly increased neural activity in the right posterior segment of the superior temporal sulcus only during mentalizing but not perspective taking. Our data further clarify the role of the posterior temporal cortex in social cognition by showing that it is involved in processing information from socially salient visual cues in situations that require the inference about other people''s mental states.     

Cerebellar contributions to biological motion perception in autism and typical development

Growing evidence suggests that posterior cerebellar lobe contributes to social perception in healthy adults. However, they know little about how this process varies across age and with development. Using cross‐sectional fMRI data, they examined cerebellar response to biological (BIO) versus scrambled (SCRAM) motion within typically developing (TD) and autism spectrum disorder (ASD) samples (age 4–30 years old), characterizing cerebellar response and BIO > SCRAM‐selective effective connectivity, as well as associations with age and social ability. TD individuals recruited regions throughout cerebellar posterior lobe during BIO > SCRAM, especially bilateral lobule VI, and demonstrated connectivity with right posterior superior temporal sulcus (RpSTS) in left VI, Crus I/II, and VIIIb. ASD individuals showed BIO > SCRAM activity in left VI and left Crus I/II, and bilateral connectivity with RpSTS in Crus I/II and VIIIb/IX. No between‐group differences emerged in well‐matched subsamples. Among TD individuals, older age predicted greater BIO > SCRAM response in left VIIb and left VIIIa/b, but reduced connectivity between RpSTS and widespread regions of the right cerebellum. In ASD, older age predicted greater response in left Crus I and bilateral Crus II, but decreased effective connectivity with RpSTS in bilateral Crus I/II. In ASD, increased BIO > SCRAM signal in left VI/Crus I and right Crus II, VIIb, and dentate predicted lower social symptomaticity; increased effective connectivity with RpSTS in right Crus I/II and bilateral VI and I–V predicted greater symptomaticity. These data suggest that posterior cerebellum contributes to the neurodevelopment of social perception in both basic and clinical populations. Hum Brain Mapp 38:1914–1932, 2017. © 2017 Wiley Periodicals, Inc.     

Overlapping and specific neural correlates for empathizing,affective mentalizing,and cognitive mentalizing: A coordinate‐based meta‐analytic study

While the discussion on the foundations of social understanding mainly revolves around the notions of empathy, affective mentalizing, and cognitive mentalizing, their degree of overlap versus specificity is still unclear. We took a meta‐analytic approach to unveil the neural bases of cognitive mentalizing, affective mentalizing, and empathy, both in healthy individuals and pathological conditions characterized by social deficits such as schizophrenia and autism. We observed partially overlapping networks for cognitive and affective mentalizing in the medial prefrontal, posterior cingulate, and lateral temporal cortex, while empathy mainly engaged fronto‐insular, somatosensory, and anterior cingulate cortex. Adjacent process‐specific regions in the posterior lateral temporal, ventrolateral, and dorsomedial prefrontal cortex might underpin a transition from abstract representations of cognitive mental states detached from sensory facets to emotionally‐charged representations of affective mental states. Altered mentalizing‐related activity involved distinct sectors of the posterior lateral temporal cortex in schizophrenia and autism, while only the latter group displayed abnormal empathy related activity in the amygdala. These data might inform the design of rehabilitative treatments for social cognitive deficits.     

Illusory own body perceptions mapped in the cingulate cortex—An intracranial stimulation study

Body awareness is the result of sensory integration in the posterior parietal cortex; however, other brain structures are part of this process. Our goal is to determine how the cingulate cortex is involved in the representation of our body. We retrospectively selected patients with drug‐resistant epilepsy, explored by stereo‐electroencephalography, that had the cingulate cortex sampled outside the epileptogenic zone. The clinical effects of high‐frequency electrical stimulation were reviewed and only those sites that elicited changes related to body perception were included. Connectivity of the cingulate cortex and other cortical structures was assessed using the h² coefficient, following a nonlinear regression analysis of the broadband EEG signal. Poststimulation changes in connectivity were compared between two sets of stimulations eliciting or not eliciting symptoms related to body awareness (interest and control groups). We included 17 stimulations from 12 patients that reported different types of body perception changes such as sensation of being pushed toward right/left/up, one limb becoming heavier/lighter, illusory sensation of movement, sensation of pressure, sensation of floating or detachment of one hemi‐body. High‐frequency stimulation in the cingulate cortex (1 anterior, 15 middle, 1 posterior part) elicits body perception changes, associated with a decreased connectivity of the dominant posterior insula and increased coupling between other structures, located particularly in the nondominant hemisphere.     

Specific default mode subnetworks support mentalizing as revealed through opposing network recruitment by social and semantic FMRI tasks

The ability to attribute mental states to others, or “mentalizing,” is posited to involve specific subnetworks within the overall default mode network (DMN), but this question needs clarification. To determine which default mode (DM) subnetworks are engaged by mentalizing processes, we assessed task‐related recruitment of DM subnetworks. Spatial independent component analysis (sICA) applied to fMRI data using relatively high‐order model (75 components). Healthy participants (n = 53, ages 17–60) performed two fMRI tasks: an interactive game involving mentalizing (Domino), a semantic memory task (SORT), and a resting state fMRI scan. sICA of the two tasks split the DMN into 10 subnetworks located in three core regions: medial prefrontal cortex (mPFC; five subnetworks), posterior cingulate/precuneus (PCC/PrC; three subnetworks), and bilateral temporoparietal junction (TPJ). Mentalizing events increased recruitment in five of 10 DM subnetworks, located in all three core DMN regions. In addition, three of these five DM subnetworks, one dmPFC subnetwork, one PCC/PrC subnetwork, and the right TPJ subnetwork, showed reduced recruitment by semantic memory task events. The opposing modulation by the two tasks suggests that these three DM subnetworks are specifically engaged in mentalizing. Our findings, therefore, suggest the unique involvement of mentalizing processes in only three of 10 DM subnetworks, and support the importance of the dmPFC, PCC/PrC, and right TPJ in mentalizing as described in prior studies. Hum Brain Mapp 36:3047–3063, 2015. © 2015 Wiley Periodicals, Inc.     

Sociotopy in the temporoparietal cortex: common versus distinct processes

A major controversy in the social cognitive neurosciences evolved around the question whether activity in the posterior superior temporal sulcus and adjacent temporoparietal junction (pSTS/TPJ-region) evoked by various tasks represents a common process or distinct processes. To investigate this question, we employed functional magnetic resonance imaging (fMRI) while participants performed Biological Motion (BM), Theory-of-Mind (ToM) and Moral Judgment (MJ) tasks. Importantly, for each task we used the same newly developed animated stimuli. Indicative of a common process, we identified small clusters of overlapping activity for BM and ToM in right pSTS and for ToM and MJ in bilateral pSTS and left TPJ. Indicative of distinct processes, on the contrary, we detected extensive dissociable activity for BM in right pSTS, for ToM in bilateral pSTS and left TPJ, and for MJ in bilateral pSTS and TPJ. Thus, our data provide strong evidence for a combined two-staged process account: (i) the parsing of a stream of visual-spatial information, represented by activity in right pSTS, where neighboring and overlapping clusters of increased responses were found for all three tasks; (ii) increasingly more complex processing of the communicative significance of other people’s behavior, represented by hierarchically increasing activity in left pSTS and bilateral TPJ elicited by ToM and MJ.     

Neural interactions in occipitotemporal cortex during basic human movement perception by dynamic causal modeling

Action recognition is an essential component of our daily life. The occipitotemporal cortex (OTC) is an important area in human movement perception. The previous studies have revealed that three vital regions including the extrastriate body area (EBA), human middle temporal complex (hMT+), and posterior superior temporal sulcus (pSTS) in OTC play an important role in motion perception. The aim of the current study is to explore the neural interactions between these three regions during basic human movement perception. Functional magnetic resonance imaging data were acquired when participants viewed dynamic videos depicting basic human movements. By the dynamic causal modeling analysis, a model space consisting of 576 models was constructed and evaluated to select the optimal model given the data. The information of the visual movement was found to enter the system through hMT+. We speculated that hMT+ would be the region to show sensitivity to the presence of motion and it subsequently influence and be influenced by the other two regions. Our results also revealed the manner in which the three regions interact during action recognition. Furthermore, We found significantly enhanced modulated connectivity from hMT+ to both EBA and pSTS, as well as from EBA to both hMT+ and pSTS. We inferred that there may be multiple routes for human action perception. One responsible route for processing motion signals is through hMT+ to pSTS, and the other projects information to pSTS may be via the form-processing route. In addition, pSTS may integrate and mediate visual signals and possibly convey them to distributed areas to maintain high-order cognitive tasks.

     

Self-oriented neural circuitry predicts other-oriented adaptive risks in adolescence: a longitudinal study

Adolescence is marked by changes in decision-making and perspective-taking abilities. Although adolescents make more adaptive decisions with age, little is understood about how adolescents take adaptive risks that impact others and how this behavior changes developmentally. Functional coupling between reward [e.g., ventral striatum (VS)] and ‘social brain’ [e.g. temporal parietal junction (TPJ)/ posterior superior temporal sulcus (pSTS), medial prefrontal cortex (mPFC)] systems may be differentially shape adaptive risks for the self and other. A total of 173 participants completed between one and three sessions across three waves [a total of 433 behavioral and 403 functional magnetic resonance imaging (fMRI) data points]. During an fMRI scan, adolescents completed a risky decision-making task where they made risky decisions to win money for themselves and their parent. The risky decisions varied in their expected value (EV) of potential reward. Results show that from the 6th through 9th grades, adolescents took increasingly more adaptive risks for themselves than for their parent. Additionally, greater VS–TPJ/pSTS and VS–mPFC connectivity that tracks EV when making risky decisions for themselves in 6th grade, but a lower VS–mPFC connectivity in 9th grade, predicted greater adaptive risk-taking for their parent. This study contributes to our understanding of the self as a neural proxy for promoting adaptive social behaviors in youth.     

Functional reorganization of intra‐ and internetwork connectivity in major depressive disorder after electroconvulsive therapy

Electroconvulsive therapy (ECT) is an effective and rapid treatment for major depressive disorder (MDD). However, the neurobiological underpinnings of ECT are still largely unknown. Recent studies have identified dysregulated brain networks in MDD. Therefore, we hypothesized that ECT may improve MDD symptoms through reorganizing these networks. To test this hypothesis, we used resting‐state functional connectivity to investigate changes to the intra‐ and internetwork architecture of five reproducible resting‐state networks: the default mode network (DMN), dorsal attention network (DAN), executive control network (CON), salience network (SAL), and sensory‐motor network. Twenty‐three MDD patients were assessed before and after ECT, along with 25 sex‐, age‐, and education‐matched healthy controls. At the network level, enhanced intranetwork connectivities were found in the CON in MDD patients after ECT. Furthermore, enhanced internetwork connectivities between the DMN and SAL, and between the CON and DMN, DAN, and SAL were also identified. At the nodal level, the posterior cingulate cortex had increased connections with the left posterior cerebellum, right posterior intraparietal sulcus (rpIPS), and right anterior prefrontal cortex. The rpIPS had increased connections with the medial PFC (mPFC) and left anterior cingulate cortex. The left lateral parietal had increased connections with the dorsal mPFC (dmPFC), left anterior prefrontal cortex, and right anterior cingulate cortex. The dmPFC had increased connection with the left anterolateral prefrontal cortex. Our findings indicate that enhanced interactions in intra‐ and internetworks may contribute to the ECT response in MDD patients. These findings provide novel and important insights into the neurobiological mechanisms underlying ECT.     

Socially tuned: Brain responses differentiating human and animal motion

Typical adult observers demonstrate enhanced behavioral sensitivity to human movement compared to animal movement. Yet, the neural underpinnings of this effect are unknown. We examined the tuning of brain mechanisms for the perception of biological motion to the social relevance of this category of motion by comparing neural response to human and non-human biological motion. In particular, we tested the hypothesis that the response of the right posterior superior temporal sulcus (pSTS) varies according to the social relevance of the motion, responding most strongly to those biological motions with the greatest social relevance (human > dog). During a functional magnetic resonance imaging (fMRI) session, typical adults viewed veridical point-light displays of human, dog, and tractor motions created from motion capture data. A conjunction analysis identified regions of significant activation during biological motion perception relative to object motion. Within each of these regions, only one brain area, the right pSTS, revealed an enhanced response to human motion relative to dog motion. This finding demonstrates that the pSTS response is sensitive to the social relevance of a biological motion stimulus.