Atypical brain activation patterns during a face‐to‐face joint attention game in adults with autism spectrum disorder

Joint attention behaviors include initiating one's own and responding to another's bid for joint attention to an object, person, or topic. Joint attention abilities in autism are pervasively atypical, correlate with development of language and social abilities, and discriminate children with autism from other developmental disorders. Despite the importance of these behaviors, the neural correlates of joint attention in individuals with autism remain unclear. This paucity of data is likely due to the inherent challenge of acquiring data during a real‐time social interaction. We used a novel experimental set‐up in which participants engaged with an experimenter in an interactive face‐to‐face joint attention game during fMRI data acquisition. Both initiating and responding to joint attention behaviors were examined as well as a solo attention (SA) control condition. Participants included adults with autism spectrum disorder (ASD) (n = 13), a mean age‐ and sex‐matched neurotypical group (n = 14), and a separate group of neurotypical adults (n = 22). Significant differences were found between groups within social‐cognitive brain regions, including dorsal medial prefrontal cortex (dMPFC) and right posterior superior temporal sulcus (pSTS), during the RJA as compared to SA conditions. Region‐of‐interest analyses revealed a lack of signal differentiation between joint attention and control conditions within left pSTS and dMPFC in individuals with ASD. Within the pSTS, this lack of differentiation was characterized by reduced activation during joint attention and relative hyper‐activation during SA. These findings suggest a possible failure of developmental neural specialization within the STS and dMPFC to joint attention in ASD. Hum Brain Mapp 34:2511–2523, 2013. © 2012 Wiley Periodicals, Inc.     

Using child‐friendly movie stimuli to study the development of face,place, and object regions from age 3 to 12 years

Scanning young children while they watch short, engaging, commercially‐produced movies has emerged as a promising approach for increasing data retention and quality. Movie stimuli also evoke a richer variety of cognitive processes than traditional experiments, allowing the study of multiple aspects of brain development simultaneously. However, because these stimuli are uncontrolled, it is unclear how effectively distinct profiles of brain activity can be distinguished from the resulting data. Here we develop an approach for identifying multiple distinct subject‐specific Regions of Interest (ssROIs) using fMRI data collected during movie‐viewing. We focused on the test case of higher‐level visual regions selective for faces, scenes, and objects. Adults (N = 13) were scanned while viewing a 5.6‐min child‐friendly movie, as well as a traditional localizer experiment with blocks of faces, scenes, and objects. We found that just 2.7 min of movie data could identify subject‐specific face, scene, and object regions. While successful, movie‐defined ssROIS still showed weaker domain selectivity than traditional ssROIs. Having validated our approach in adults, we then used the same methods on movie data collected from 3 to 12‐year‐old children (N = 122). Movie response timecourses in 3‐year‐old children''s face, scene, and object regions were already significantly and specifically predicted by timecourses from the corresponding regions in adults. We also found evidence of continued developmental change, particularly in the face‐selective posterior superior temporal sulcus. Taken together, our results reveal both early maturity and functional change in face, scene, and object regions, and more broadly highlight the promise of short, child‐friendly movies for developmental cognitive neuroscience.     

Differences between smokers and nonsmokers in regional gray matter volumes and densities.

BACKGROUND: Magnetic resonance imaging (MRI) studies have demonstrated large-scale brain abnormalities in cigarette smokers, such as ventricular enlargement and atrophy. Converging lines of evidence point to functional differences between smokers and nonsmokers in specific brain regions, namely the lateral prefrontal cortex (PFC), anterior cingulate cortex (ACC), ventral striatum, and thalamus. Using MRI, we examined these regions for differences in gray matter between smokers and nonsmokers. METHODS: Thirty-six otherwise healthy adults (19 smokers and 17 nonsmoking control subjects) underwent three-dimensional Fourier-transform spoiled-gradient-recalled acquisition MRI of the brain. Both hand-drawn regions of interest and the computer program voxel-based morphometry were used to assess group differences in regional gray matter volumes and densities, respectively. RESULTS: Smokers had smaller gray matter volumes and lower gray matter densities than nonsmokers in the PFC bilaterally, along with smaller volumes in the left dorsal ACC and lower gray matter densities in the right cerebellum. Smokers also had negative associations between pack-year smoking history and PFC gray matter densities. CONCLUSIONS: Smokers and nonsmokers differed in regional gray matter in brain areas previously linked with nicotine dependence. These findings might reflect effects of chronic smoking, predisposing traits that lead to smoking, or some combination of these factors.     

The role of the subgenual anterior cingulate cortex in dorsomedial prefrontal–amygdala neural circuitry during positive‐social emotion regulation

Positive‐social emotions mediate one's cognitive performance, mood, well‐being, and social bonds, and represent a critical variable within therapeutic settings. It has been shown that the upregulation of positive emotions in social situations is associated with increased top‐down signals that stem from the prefrontal cortices (PFC) which modulate bottom‐up emotional responses in the amygdala. However, it remains unclear if positive‐social emotion upregulation of the amygdala occurs directly through the dorsomedial PFC (dmPFC) or indirectly linking the bilateral amygdala with the dmPFC via the subgenual anterior cingulate cortex (sgACC), an area which typically serves as a gatekeeper between cognitive and emotion networks. We performed functional MRI (fMRI) experiments with and without effortful positive‐social emotion upregulation to demonstrate the functional architecture of a network involving the amygdala, the dmPFC, and the sgACC. We found that effortful positive‐social emotion upregulation was associated with an increase in top‐down connectivity from the dmPFC on the amygdala via both direct and indirect connections with the sgACC. Conversely, we found that emotion processes without effortful regulation increased network modulation by the sgACC and amygdala. We also found that more anxious individuals with a greater tendency to suppress emotions and intrusive thoughts, were likely to display decreased amygdala, dmPFC, and sgACC activity and stronger connectivity strength from the sgACC onto the left amygdala during effortful emotion upregulation. Analyzed brain network suggests a more general role of the sgACC in cognitive control and sheds light on neurobiological informed treatment interventions.     

Functional dissociations between four basic arithmetic operations in the human posterior parietal cortex: a cytoarchitectonic mapping study

Although lesion studies over the past several decades have focused on functional dissociations in posterior parietal cortex (PPC) during arithmetic, no consistent view has emerged of its differential involvement in addition, subtraction, multiplication, and division. To circumvent problems with poor anatomical localization, we examined functional overlap and dissociations in cytoarchitectonically defined subdivisions of the intraparietal sulcus (IPS), superior parietal lobule (SPL) and angular gyrus (AG), across these four operations. Compared to a number identification control task, all operations except addition, showed a consistent profile of left posterior IPS activation and deactivation in the right posterior AG. Multiplication and subtraction differed significantly in right, but not left, IPS and AG activity, challenging the view that the left AG differentially subserves retrieval during multiplication. Although addition and multiplication both rely on retrieval, multiplication evoked significantly greater activation in right posterior IPS, as well as the prefrontal cortex, lingual and fusiform gyri, demonstrating that addition and multiplication engage different brain processes. Comparison of PPC responses to the two pairs of inverse operations: division versus multiplication and subtraction versus addition revealed greater activation of left lateral SPL during division, suggesting that processing inverse relations is operation specific. Our findings demonstrate that individual IPS, SPL and AG subdivisions are differentially modulated by the four arithmetic operations and they point to significant functional heterogeneity and individual differences in activation and deactivation within the PPC. Critically, these effects are related to retrieval, calculation and inversion, the three key cognitive processes that are differentially engaged by arithmetic operations. Our findings point to distribute representation of these processes in the human PPC and also help explain why lesion and previous imaging studies have yielded inconsistent findings.     

Neocortical modulation of the amygdala response to fearful stimuli.

BACKGROUND: The cortical circuitry involved in conscious cognitive processes and the subcortical circuitry involved in fear responses have been extensively studied with neuroimaging, but their interactions remain largely unexplored. A recent functional magnetic resonance imaging (fMRI) study demonstrated that the engagement of the right prefrontal cortex during the cognitive evaluation of angry and fearful facial expressions is associated with an attenuation of the response of the amygdala to these same stimuli, providing evidence for a functional neural network for emotional regulation. METHODS: In the current study, we have explored the generalizability of this functional network by using threatening and fearful non-face stimuli derived from the International Affective Picture System (IAPS), as well as the influence of this network on peripheral autonomic responses. RESULTS: Similar to the earlier findings with facial expressions, blood oxygen level dependent fMRI revealed that whereas perceptual processing of IAPS stimuli was associated with a bilateral amygdala response, cognitive evaluation of these same stimuli was associated with attenuation of this amygdala response and a correlated increase in response of the right prefrontal cortex and the anterior cingulate cortex. Moreover, this pattern was reflected in changes in skin conductance. CONCLUSIONS: The current results further implicate the importance of neocortical regions, including the prefrontal and anterior cingulate cortices, in regulating emotional responses mediated by the amygdala through conscious evaluation and appraisal.     

Gray matter volume deficits and correlation with insight and negative symptoms in first-psychotic-episode subjects

Bergé D, Carmona S, Rovira M, Bulbena A, Salgado P, Vilarroya O. Gray matter volume deficits and correlation with insight and negative symptoms in first‐psychotic‐episode subjects. Objective: To determine brain areas reduced in first episode of psychotic subjects and its association with lack of insight and negative symptoms. Method: Twenty‐one drug naive first‐episode subjects and 20 controls underwent a structural MRI scan and were clinically assessed. Optimized voxel‐based‐morphometry analysis (VBM) was implemented to find between‐group differences and correlations between GM volume and: (i) lack of insight and (ii) negative symptoms. Results: Patients showed GM reduction in prefrontal and left temporal areas. A significant correlation was found between insight and GM volume in the cerebellum (corrected P = 0.01), inferior temporal gyrus (corrected P = 0.022), medial superior frontal gyrus (corrected P < 0.001), and inferior frontal gyrus (corrected P = 0.012), as the insight decreased, the volume decreased. Negative symptoms correlated with decreased GM volume at cerebellum (corrected P = 0.037) and frontal inferior regions (corrected P < 0.001), the more negative symptoms, the less volume. Conclusion: Our findings support an association between prefrontal, temporal, and cerebellar deficits and lack of insight in schizophrenia and confirm previous findings of GM deficits in patients since the first episode of psychosis.     

Aging effects on regional brain structural changes in schizophrenia

Background: Although mostly conceptualized as a neurodevelopmental disorder, there is an increasing interest in progressive changes of cognitive deficits and brain structure and function in schizophrenia across the life span.Methods: In this study, we investigated age-related changes in regional gray matter using voxel-based morphometry in a sample of 99 patients (age range 18–65 years) with Diagnostic and Statistical Manual of Mental Disorders-IV schizophrenia and 113 healthy controls (age range 19–59 years) using a cross-sectional design.Results: We found steeper age-related decline in gray matter in patients in a cluster comprising the left superior temporal cortex and adjacent inferior parietal lobule. We then divided the schizophrenia sample in 3 subgroups based on a 3-factor model of psychopathology ratings. Age-related changes were markedly different in each of the 3 subgroups (compared with healthy controls). While patients with predominantly paranoid symptoms showed stronger age-related progression in the left superior temporal cortex and right inferior frontal gyrus, those of the disorganized subgroup had stronger gray matter loss in the left lateral cerebellum, while the predominantly negative subgroup showed minor effects in the left superior temporal gyrus.Conclusions: Our findings show that differences in brain structural changes associated with aging diverge between schizophrenia patients and healthy subjects and that different subgroups within a patient sample might be at higher risk of age-related regional gray matter loss.     

Dorsolateral prefrontal and superior temporal volume deficits in first–episode psychoses that evolve into schizophrenia

Regions with a likely involvement in schizophrenia may differ between patients with firstepisodes of psychosis respectively with and without evolution into schizophrenia following the initial episode. We have used magnetic resonance imaging (MRI) to assess the volumes of dorsolateral prefrontal (DLPF) and superior temporal gyrus (STG) in a group of 37 first–episode psychotic patients. After an initial MRI study performed by the time of the first episode, the subjects were followed for two years. After this period 22 cases were diagnosed with schizophrenia, while the other 15 did not show clinical evidence for this illness. A Talairach–based tool was used for segmentation and volumetry of the MRI scans. A group of 44 healthy controls was used for comparison and, using lineal regression, to control for the normal effects of age and intracranial volume on the regional parameters of the patients. By the time of their first episode, patients with schizophrenia had significantly less grey matter in the right DLPF and STG regions as compared to both controls and FE without schizophrenia. Nevertheless, these parameters could not predict final diagnosis in a discriminant analysis model. Our findings indicate that subtle structural defects are already found by the time of the first psychotic break in schizophrenia, although clinical implications for these differences seem unclear.     

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.     

On the involvement of prefrontal networks in cognitive ageing

Normal ageing is associated with a wide variety of disturbances in the structure and function of the human brain. Recent neuroimaging studies suggest that the prefrontal cortex (PFC) is particularly vulnerable to the effects of ageing. These findings are compatible with the so-called ‘frontal ageing hypothesis' which has been formulated on the basis of neuropsychological research on non-pathological ageing. We will argue on the basis of recent structural and functional neuroimaging studies that this hypothesis needs to be refined, especially to acknowledge the possible relevance of a distinction between subregions within the PFC. In addition, findings with regard to a differential involvement of grey versus white matter suggest that both have to be considered in relation to age- related cognitive decline. Hence, neural networks and larger systems of interconnected brain regions and the functional activity in these circuits may be more important than specific cortical regions to explain age effects on cognitive functioning. Finally, it is important to consider individual variability due to sex differences and age-extrinsic biomedical factors in research which examines the relationship between brain structure or function and cognitive ageing.     

Automated MRI parcellation study of regional volume and thickness of prefrontal cortex (PFC) in antipsychotic-naïve schizophrenia

Objective: Prefrontal cortical dysfunction is considered to be critical in the pathogenesis of schizophrenia. However, structural magnetic resonance imaging (MRI) studies on the PFC have yielded inconsistent results because of various confounding factors. Method: In this study we examined the volume and thickness abnormalities of the PFC in antipsychotic‐naïve schizophrenia patients (n = 51) in comparison with age‐, sex‐, and handedness‐matched (as a group) healthy comparison subjects (n = 47) using a newly described automated MRI parcellation analysis. Results: Schizophrenia patients showed i) significant volume deficits in bilateral lateral orbitofrontal and left medial orbitofrontal cortices as well as bilateral pars triangularis; and ii) significant thickness deficit in bilateral medial orbitofrontal cortices. Negative syndrome score had a significant negative correlation with the thickness of the left medial orbitofrontal cortex. Conclusion: The study findings emphasize that prefrontal deficit in schizophrenia is differential and involves primarily the regions essential for ‘social cognition’.     

Regional brain activation changes and abnormal functional connectivity of the ventrolateral prefrontal cortex during working memory processing in adults with attention‐deficit/hyperactivity disorder

Previous studies on working memory (WM) function in adults with attention‐deficit/hyperactivity disorder (ADHD) suggested aberrant activation of the prefrontal cortex and the cerebellum. Although it has been hypothesized that activation differences in these regions most likely reflect aberrant frontocerebellar circuits, the functional coupling of these brain networks during cognitive performance has not been investigated so far. In this study, functional magnetic resonance imaging (fMRI) and both univariate and multivariate analytic techniques were used to investigate regional activation changes and functional connectivity differences during cognitive processing in healthy controls (n = 12) and ADHD adults (n = 12). Behavioral performance during a parametric verbal WM paradigm did not significantly differ between adults with ADHD and healthy controls. During the delay period of the activation task, however, ADHD patients showed significantly less activation in the left ventrolateral prefrontal cortex (VLPFC), as well as in cerebellar and occipital regions compared with healthy control subjects. In both groups, independent component analyses revealed a functional network comprising bilateral lateral prefrontal, striatal, and cingulate regions. ADHD adults had significantly lower connectivity in the bilateral VLPFC, the anterior cingulate cortex, the superior parietal lobule, and the cerebellum compared with healthy controls. Increased connectivity in ADHD adults was found in right prefrontal regions, the left dorsal cingulate cortex and the left cuneus. These findings suggest both regional brain activation deficits and functional connectivity changes of the VLPFC and the cerebellum as well as functional connectivity abnormalities of the anterior cingulate and the parietal cortex in ADHD adults during WM processing. Hum Brain Mapp, 2009. © 2008 Wiley‐Liss, Inc.     

A systematic fMRI investigation of the brain systems subserving different working memory components in schizophrenia

Working memory impairment is one of the cardinal cognitive disturbances in schizophrenia and considerable evidence suggests that it can be traced to functional alterations in the brain. The exact allocation of specific deficits to regional specific dysfunctions, however, remains elusive. The aim of this study was to examine the functional integrity of three distinguishable brain systems underlying maintenance-related subprocesses of working memory (articulatory rehearsal, non-articulatory maintenance of phonological information, maintenance of visuospatial information) in patients with schizophrenia. Using an experimental paradigm, which had been designed to selectively activate these different brain systems, we assessed the brain activation of patients and controls with functional magnetic resonance imaging. Compared with controls, patients showed reduced activation of the fronto-opercular, intraparietal and anterior cingulate cortex during the non-articulatory maintenance of phonological information, as well as attenuated deactivation of the hippocampus. Additionally, we found prefrontal activation to depend critically on the patients' current symptom status. During visuospatial maintenance, patients showed impaired activation of the superior parietal, temporal and occipital cortex, combined with enhanced activation of the frontal eye field and the inferior parietal cortex. No abnormal activations were observed during the articulatory rehearsal task. All activation differences were independent of group differences in task performance. Our fine-grained analysis of dysfunctions in particular aspects of working memory circuitry provides evidence for a differential impairment of the brain systems supporting working memory subcomponents in schizophrenia and extends knowledge of the relationship between cognitive deficits, brain activation abnormalities and symptoms in schizophrenia.     

From hippocampus to whole‐brain: The role of integrative processing in episodic memory retrieval

Multivariate functional connectivity analyses of neuroimaging data have revealed the importance of complex, distributed interactions between disparate yet interdependent brain regions. Recent work has shown that topological properties of functional brain networks are associated with individual and group differences in cognitive performance, including in episodic memory. After constructing functional whole‐brain networks derived from an event‐related fMRI study of memory retrieval, we examined differences in functional brain network architecture between forgotten and remembered words. This study yielded three main findings. First, graph theory analyses showed that successfully remembering compared to forgetting was associated with significant changes in the connectivity profile of the left hippocampus and a corresponding increase in efficient communication with the rest of the brain. Second, bivariate functional connectivity analyses indicated stronger interactions between the left hippocampus and a retrieval assembly for remembered versus forgotten items. This assembly included the left precuneus, left caudate, bilateral supramarginal gyrus, and the bilateral dorsolateral superior frontal gyrus. Integrative properties of the retrieval assembly were greater for remembered than forgotten items. Third, whole‐brain modularity analyses revealed that successful memory retrieval was marginally significantly associated with a less segregated modular architecture in the network. The magnitude of the decreases in modularity between remembered and forgotten conditions was related to memory performance. These findings indicate that increases in integrative properties at the nodal, retrieval assembly, and whole‐brain topological levels facilitate memory retrieval, while also underscoring the potential of multivariate brain connectivity approaches for providing valuable new insights into the neural bases of memory processes. Hum Brain Mapp 38:2242–2259, 2017. © 2017 Wiley Periodicals, Inc.     

Distinct neural activation patterns underlie economic decisions in high and low psychopathy scorers

Psychopathic traits affect social functioning and the ability to make adaptive decisions in social interactions. This study investigated how psychopathy affects the neural mechanisms that are recruited to make decisions in the ultimatum game. Thirty-five adult participants recruited from the community underwent functional magnetic resonance imaging scanning while they performed the ultimatum game under high and low cognitive load. Across load conditions, high psychopathy scorers rejected unfair offers in the same proportion as low scorers, but perceived them as less unfair. Among low scorers, the perceived fairness of offers predicted acceptance rates, whereas in high scorers no association was found. Imaging results revealed that responses in each group were associated with distinct patterns of brain activation, indicating divergent decision mechanisms. Acceptance of unfair offers was associated with dorsolateral prefrontal cortex activity in low scorers and ventromedial prefrontal cortex activity in high scorers. Overall, our findings point to distinct motivations for rejecting unfair offers in individuals who vary in psychopathic traits, with rejections in high psychopathy scorers being probably induced by frustration. Implications of these results for models of ventromedial prefrontal cortex dysfunction in psychopathy are discussed.     

Brain activation and functional connectivity in premanifest Huntington's disease during states of intrinsic and phasic alertness

Previous functional neuroimaging studies have shown brain activation abnormalities in clinically presymptomatic carriers of the Huntington's disease (preHD) gene mutation when performing complex cognitive tasks. However, little is known about the neural correlates of attentional processes in preHD. In this study, we used functional magnetic resonance imaging to investigate basic aspects of attentional processing in preHD individuals (n = 18) compared to healthy participants (n = 18) during an alertness task. Uni‐ and multivariate statistical techniques were used to assess task‐related regional brain activation and functional network connectivity. Compared to healthy controls, preHD individuals near to the estimated onset of clinical signs showed lower activation of right frontostriatal regions during phasic alertness (P < 0.001, uncorrected). Decreased striatal activation in this preHD subgroup was also evident when compared with those preHD individuals far from the estimated onset of HD signs. Lower putaminal activity was associated with longer reaction times and with proximity to onset. In addition, preHD participants near to onset had lower functional connectivity of motor regions when compared with controls and preHD individuals far from onset. Our data suggest that while alertness‐related performance remains normal, the underlying frontostriatal activity and motor cortex connectivity decline only when approaching the onset of unequivocal signs of HD. However, these attentional network changes might not be the sole explanation for the differences in cognitive task performance previously observed in preHD. Hum Brain Mapp 33:2161–2173, 2012. © 2011 Wiley Periodicals, Inc.     

Foreshortened dorsal extension of the central sulcus in Williams syndrome

Williams syndrome (WMS) is a genetic condition resulting from a hemideletion on chromosome 7 that causes cognitive impairment, and a variety of growth and physical abnormalities. Little is currently known about brain morphology in WMS, although one recent MRI report suggested that the central sulcus was abnormally short on its dorsal end compared to normal IQ controls. We sought to replicate this finding in a group of 28 persons with WMS in comparison to both an age and sex matched normal IQ control group (n = 22). In addition, we sought to test the specificity of this finding by a further comparison to an IQ matched control group (n = 20). Using high resolution isotropic voxel MRI, the dorsal and ventral extension of the central sulcus was traced and the distance from the interhemispheric and sylvian fissures was measured. The dorsal extension of the central sulcus in both hemispheres was significantly more distant from the interhemispheric fissure in WMS compared to the lower IQ group and to the normal control group (p's < 0.001). There was no significant difference between groups in the ventral end of the central sulcus. These results suggest that the abnormal dorsal end of the central sulcus may be a specific characteristic of WMS not shared with general mental retardation or low IQ.     

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.     

Morphometric alterations of anterior superior temporal cortex in obsessive-compulsive disorder

The superior temporal gyrus (STG) may be involved in the pathophysiology of obsessive-compulsive disorder (OCD). Moreover, the anterior STG has rich interconnections with the orbitofrontal cortex and the amygdala, and plays a role in visuospatial processing, which is impaired in patients with OCD. This study was designed to examine the morphological abnormalities of the anterior STG and their relationships with visuospatial function and clinical symptom in patients with OCD. We measured gray matter volumes of the anterior STG [rostral STG and planum polare (PP)] by three-dimensional (3D) magnetic resonance imaging in age- and sex-matched groups, which consisted of 22 patients with OCD and 22 normal volunteers. Visuospatial function and clinical symptom were assessed using the Rey-Osterrieth Complex Figure (ROCF) test, the Yale-Brown Obsessive Compulsive Scale, and the Maudsley Obsessive Compulsive Inventory. We found significant volume reductions in bilateral PPs, but there were no significant correlations between brain volumes and the ROCF copy score, immediate or delayed recall score, and clinical symptom in patients with OCD. These results suggest that volume reduction of the anterior STG, especially the PP, may be related to the pathophysiology of OCD, but further research may be needed to explore a relationship of the PP volume change with cognitive impairment observed in patients with OCD.