The social brain in psychiatric and neurological disorders

Failing as doorman and disc jockey at the same time: Amygdalar dysfunction in Parkinson's disease

In Braak's model of ascending degeneration in Parkinson's disease (PD), involvement of the amygdala occurs simultaneously with substantia nigra degeneration. However, the clinical manifestations of amygdalar involvement in PD have not been fully delineated. Considered a multitask manager, the amygdala is a densely connected "hub," coordinating and integrating tasks ranging from prompt, multisensorial emotion recognition to adequate emotional responses and emotional tuning of memories. Although phylogenetically predisposed to handle fear, the amygdala handles both aversive and positive emotional inputs. In PD, neuropathological and in vivo studies suggest primarily amygdalar hypofunction. However, as dopamine acts as an inverted U-shaped amygdalar modulator, medication-induced hyperactivity of the amygdala can occur. We propose that amygdalar (network) dysfunction contributes to reduced recognition of negative emotional face expressions, impaired theory of mind, reactive hypomimia, and impaired decision making. Similarly, impulse control disorders in predisposed individuals, hallucinations, anxiety, and panic attacks may be related to amygdalar dysfunction. When available, we discuss amygdala-independent trigger mechanisms of these symptoms. Although dopaminergic agents have mostly an activation effect on amygdalar function, adaptive and compensatory network changes may occur as well, but these have not been sufficiently explored. In conclusion, our model of amygdalar involvement brings together several elements of Parkinson's disease phenomenology heretofore left unexplained and provides a framework for testable hypotheses in patients during life and in autopsy analyses.

Getting to know you: general and specific neural computations for learning about people

Learning about other peoples' attributes, e.g. whether an individual is generous or selfish, is central to human social cognition. It is well documented that a network of cortical regions is reliably activated when we engage social processes. However, little is known about the specific computations performed by these regions or whether such processing is specialized for the social domain. We investigated these questions using a task in which participants (N= 26) learned about four peoples' generosity by watching them choose to share money with third party partners, or not. In a non-social control condition, participants learned the win/loss rates of four lotteries. fMRI analysis revealed learning-related general (social + non-social) prediction error signals in the dorsomedial and dorsolateral prefrontal cortices (bilaterally), and in the right lateral parietal cortex. Socially specific (social > non-social) prediction error signals were found in the precuneus. Interestingly, the region that exhibited social prediction errors was a distinct subregion of the area in the precuneus and posterior cingulate cortex that exhibited a commonly reported main effect of higher overall activity for social vs non-social stimuli. These findings elucidate the domain--general and--specific computations underlying learning about other people and demonstrate the increased explanatory power of computational approaches to social cognition.

Specific Regional and Age-Related Small Noncoding RNA Expression Patterns Within Superior Temporal Gyrus of Typical Human Brains Are Less Distinct in Autism Brains

Small noncoding RNAs play a critical role in regulating messenger RNA throughout brain development and when altered could have profound effects leading to disorders such as autism spectrum disorders (ASD). We assessed small noncoding RNAs, including microRNA and small nucleolar RNA, in superior temporal sulcus association cortex and primary auditory cortex in typical and ASD brains from early childhood to adulthood. Typical small noncoding RNA expression profiles were less distinct in ASD, both between regions and changes with age. Typical micro-RNA coexpression associations were absent in ASD brains. miR-132, miR-103, and miR-320 micro-RNAs were dysregulated in ASD and have previously been associated with autism spectrum disorders. These diminished region- and age-related micro-RNA expression profiles are in line with previously reported findings of attenuated messenger RNA and long noncoding RNA in ASD brain. This study demonstrates alterations in superior temporal sulcus in ASD, a region implicated in social impairment, and is the first to demonstrate molecular alterations in the primary auditory cortex.

Translational Meta-analytical Methods to Localize the Regulatory Patterns of Neurological Disorders in the Human Brain

The task of mapping neurological disorders in the human brain must be informed by multiple measurements of an individual's phenotype - neuroimaging, genomics, and behavior. We developed a novel meta-analytical approach to integrate disparate resources and generated transcriptional maps of neurological disorders in the human brain yielding a purely computational procedure to pinpoint the brain location of transcribed genes likely to be involved in either onset or maintenance of the neurological condition.

Implicit Social Biases in People With Autism

Implicit social biases are ubiquitous and are known to influence social behavior. A core diagnostic criterion of autism spectrum disorders (ASD) is abnormal social behavior. We investigated the extent to which individuals with ASD might show a specific attenuation of implicit social biases, using Implicit Association Tests (IATs) involving social (gender, race) and nonsocial (nature, shoes) categories. High-functioning adults with ASD showed intact but reduced IAT effects relative to healthy control participants. We observed no selective attenuation of implicit social (vs. nonsocial) biases in our ASD population. To extend these results, we supplemented our healthy control data with data collected from a large online sample from the general population and explored correlations between autistic traits and IAT effects. We observed no systematic relationship between autistic traits and implicit social biases in our online and control samples. Taken together, these results suggest that implicit social biases, as measured by the IAT, are largely intact in ASD.

Embryological exposure to valproic acid induces social interaction deficits in zebrafish (Danio rerio): A developmental behavior analysis

Changes in social behavior are associated with brain disorders, including mood disorders, stress, schizophrenia, Alzheimer's disease, and autism spectrum disorders (ASD). Autism is a complex neurodevelopmental disorder characterized by deficits in social interaction, impaired communication, anxiety, hyperactivity, and the presence of restricted interests. Zebrafish is one of the most social vertebrates used as a model in biomedical research, contributing to an understanding of the mechanisms that underlie social behavior. Valproic acid (VPA) is used as an anti-epileptic drug and mood stabilizer; however, prenatal VPA exposure in humans has been associated with an increased incidence of autism and it can also affect fetal brain development. Therefore, we conducted a behavioral screening at different periods of zebrafish development at 6, 30, 70, and 120dpf (days postfertilization) after VPA exposure in the early development stage to investigate social behavior, locomotion, aggression, and anxiety. VPA (48μM) exposure during the first 48hpf (hours postfertilization) did not promote changes on survival, morphology, and hatching rate at 24hpf, 48hpf, and 72hpf. The behavioral patterns suggest that VPA exposure induces changes in locomotor activity and anxiety at different developmental periods in zebrafish. Furthermore, a social interaction deficit is present at 70dpf and 120dpf. VPA exposure did not affect aggression in the adult stage at 70dpf and 120dpf. This is the first study that demonstrated zebrafish exposed to VPA during the first 48h of development exhibit deficits in social interaction, anxiety, and hyperactivity at different developmental periods.

Neuronal and Cardiovascular Potassium Channels as Therapeutic Drug Targets: Promise and Pitfalls

Potassium (K(+)) channels, with their diversity, often tissue-defined distribution, and critical role in controlling cellular excitability, have long held promise of being important drug targets for the treatment of dysrhythmias in the heart and abnormal neuronal activity within the brain. With the exception of drugs that target one particular class, ATP-sensitive K(+) (KATP) channels, very few selective K(+) channel activators or inhibitors are currently licensed for clinical use in cardiovascular and neurological disease. Here we review what a range of human genetic disorders have told us about the role of specific K(+) channel subunits, explore the potential of activators and inhibitors of specific channel populations as a therapeutic strategy, and discuss possible reasons for the difficulty in designing clinically relevant K(+) channel modulators.

Development of social skills in children: neural and behavioral evidence for the elaboration of cognitive models

Social skills refer to a wide group of abilities that allow us to interact and communicate with others. Children learn how to solve social situations by predicting and understanding other's behaviors. The way in which humans learn to interact successfully with others encompasses a complex interaction between neural, behavioral, and environmental elements. These have a role in the accomplishment of positive developmental outcomes, including peer acceptance, academic achievement, and mental health. All these social abilities depend on widespread brain networks that are recently being studied by neuroscience. In this paper, we will first review the studies on this topic, aiming to clarify the behavioral and neural mechanisms related to the acquisition of social skills during infancy and their appearance in time. Second, we will briefly describe how developmental diseases like Autism Spectrum Disorders (ASD) can inform about the neurobiological mechanisms of social skills. We finally sketch a general framework for the elaboration of cognitive models in order to facilitate the comprehension of human social development.

Common and distinct networks for self-referential and social stimulus processing in the human brain

Self-referential processing is a complex cognitive function, involving a set of implicit and explicit processes, complicating investigation of its distinct neural signature. The present study explores the functional overlap and dissociability of self-referential and social stimulus processing. We combined an established paradigm for explicit self-referential processing with an implicit social stimulus processing paradigm in one fMRI experiment to determine the neural effects of self-relatedness and social processing within one study. Overlapping activations were found in the orbitofrontal cortex and in the intermediate part of the precuneus. Stimuli judged as self-referential specifically activated the posterior cingulate cortex, the ventral medial prefrontal cortex, extending into anterior cingulate cortex and orbitofrontal cortex, the dorsal medial prefrontal cortex, the ventral and dorsal lateral prefrontal cortex, the left inferior temporal gyrus, and occipital cortex. Social processing specifically involved the posterior precuneus and bilateral temporo-parietal junction. Taken together, our data show, not only, first, common networks for both processes in the medial prefrontal and the medial parietal cortex, but also, second, functional differentiations for self-referential processing versus social processing: an anterior-posterior gradient for social processing and self-referential processing within the medial parietal cortex and specific activations for self-referential processing in the medial and lateral prefrontal cortex and for social processing in the temporo-parietal junction.

Emotional Processing, Recognition, Empathy and Evoked Facial Expression in Eating Disorders: An Experimental Study to Map Deficits in Social Cognition

BACKGROUND

Difficulties in social cognition have been identified in eating disorders (EDs), but the exact profile of these abnormalities is unclear. The aim of this study is to examine distinct processes of social-cognition in this patient group, including attentional processing and recognition, empathic reaction and evoked facial expression in response to discrete vignettes of others displaying positive (i.e. happiness) or negative (i.e. sadness and anger) emotions.

METHOD

One hundred and thirty-eight female participants were included in the study: 73 healthy controls (HCs) and 65 individuals with an ED (49 with Anorexia Nervosa and 16 with Bulimia Nervosa). Self-report and behavioural measures were used.

RESULTS

Participants with EDs did not display specific abnormalities in emotional processing, recognition and empathic response to others' basic discrete emotions. However, they had poorer facial expressivity and a tendency to turn away from emotional displays.

CONCLUSION

Treatments focusing on the development of non-verbal emotional communication skills might be of benefit for patients with EDs.

Realizing the potential of mobile mental health: new methods for new data in psychiatry

Smartphones are now ubiquitous and can be harnessed to offer psychiatry a wealth of real-time data regarding patient behavior, self-reported symptoms, and even physiology. The data collected from smartphones meet the three criteria of big data: velocity, volume, and variety. Although these data have tremendous potential, transforming them into clinically valid and useful information requires using new tools and methods as a part of assessment in psychiatry. In this paper, we introduce and explore numerous analytical methods and tools from the computational and statistical sciences that appear readily applicable to psychiatric data collected using smartphones. By matching smartphone data with appropriate statistical methods, psychiatry can better realize the potential of mobile mental health and empower both patients and providers with novel clinical tools.

Increased Functional Connectivity Between Subcortical and Cortical Resting-State Networks in Autism Spectrum Disorder

IMPORTANCE

Individuals with autism spectrum disorder (ASD) exhibit severe difficulties in social interaction, motor coordination, behavioral flexibility, and atypical sensory processing, with considerable interindividual variability. This heterogeneous set of symptoms recently led to investigating the presence of abnormalities in the interaction across large-scale brain networks. To date, studies have focused either on constrained sets of brain regions or whole-brain analysis, rather than focusing on the interaction between brain networks.

OBJECTIVES

To compare the intrinsic functional connectivity between brain networks in a large sample of individuals with ASD and typically developing control subjects and to estimate to what extent group differences would predict autistic traits and reflect different developmental trajectories.

DESIGN, SETTING, AND PARTICIPANTS

We studied 166 male individuals (mean age, 17.6 years; age range, 7-50 years) diagnosed as having DSM-IV-TR autism or Asperger syndrome and 193 typical developing male individuals (mean age, 16.9 years; age range, 6.5-39.4 years) using resting-state functional magnetic resonance imaging (MRI). Participants were matched for age, IQ, head motion, and eye status (open or closed) in the MRI scanner. We analyzed data from the Autism Brain Imaging Data Exchange (ABIDE), an aggregated MRI data set from 17 centers, made public in August 2012.

MAIN OUTCOMES AND MEASURES

We estimated correlations between time courses of brain networks extracted using a data-driven method (independent component analysis). Subsequently, we associated estimates of interaction strength between networks with age and autistic traits indexed by the Social Responsiveness Scale.

RESULTS

Relative to typically developing control participants, individuals with ASD showed increased functional connectivity between primary sensory networks and subcortical networks (thalamus and basal ganglia) (all t ≥ 3.13, P < .001 corrected). The strength of such connections was associated with the severity of autistic traits in the ASD group (all r ≥ 0.21, P < .0067 corrected). In addition, subcortico-cortical interaction decreased with age in the entire sample (all r ≤ -0.09, P < .012 corrected), although this association was significant only in typically developing participants (all r ≤ -0.13, P < .009 corrected).

CONCLUSIONS AND RELEVANCE

Our results showing ASD-related impairment in the interaction between primary sensory cortices and subcortical regions suggest that the sensory processes they subserve abnormally influence brain information processing in individuals with ASD. This might contribute to the occurrence of hyposensitivity or hypersensitivity and of difficulties in top-down regulation of behavior.

Bidirectional modulation of anxiety-related and social behaviors by amygdala projections to the medial prefrontal cortex

The basolateral amygdala (BLA) and the medial prefrontal cortex (mPFC) modulate anxiety and social behaviors. It remains to be elucidated, however, whether direct projections from the BLA to the mPFC play a functional role in these behaviors. We used optogenetic approaches in behaving mice to either activate or inhibit BLA inputs to the mPFC during behavioral assays that assess anxiety-like behavior and social interaction. Channelrhodopsin-2 (ChR2)-mediated activation of BLA inputs to the mPFC produced anxiogenic effects in the elevated plus maze and open field test, whereas halorhodopsin (NpHR)-mediated inhibition produced anxiolytic effects. Furthermore, activation of the BLA-mPFC pathway reduced social interaction in the resident-intruder test, whereas inhibition facilitated social interaction. These results establish a causal relationship between activity in the BLA-mPFC pathway and the bidirectional modulation of anxiety-related and social behaviors.

Abnormal Social Reward Responses in Anorexia Nervosa: An fMRI Study

Patients with anorexia nervosa (AN) display impaired social interactions, implicated in the development and prognosis of the disorder. Importantly, social behavior is modulated by reward-based processes, and dysfunctional at-brain-level reward responses have been involved in AN neurobiological models. However, no prior evidence exists of whether these neural alterations would be equally present in social contexts. In this study, we conducted a cross-sectional social-judgment functional magnetic resonance imaging (fMRI) study of 20 restrictive-subtype AN patients and 20 matched healthy controls. Brain activity during acceptance and rejection was investigated and correlated with severity measures (Eating Disorder Inventory -EDI-2) and with personality traits of interest known to modulate social behavior (The Sensitivity to Punishment and Sensitivity to Reward Questionnaire). Patients showed hypoactivation of the dorsomedial prefrontal cortex (DMPFC) during social acceptance and hyperactivation of visual areas during social rejection. Ventral striatum activation during rejection was positively correlated in patients with clinical severity scores. During acceptance, activation of the frontal opercula-anterior insula and dorsomedial/dorsolateral prefrontal cortices was differentially associated with reward sensitivity between groups. These results suggest an abnormal motivational drive for social stimuli, and involve overlapping social cognition and reward systems leading to a disruption of adaptive responses in the processing of social reward. The specific association of reward-related regions with clinical and psychometric measures suggests the putative involvement of reward structures in the maintenance of pathological behaviors in AN.

Increased Surface Area, but not Cortical Thickness, in a Subset of Young Boys With Autism Spectrum Disorder

The Autism Phenome Project is the largest, single site, longitudinal magnetic resonance imaging (MRI) study of young children with autism spectrum disorder (ASD). Previous analyses from this cohort have shown that the children with autism have a total brain volume at time 1 (∼3 years of age) that is 6% larger than typically developing (TD) children. This finding is driven primarily by 15% of the boys with ASD that have disproportionate megalencephaly (ASD-DM) or brain size that is 1.5 standard deviations above what would be expected for the child's height. In the current study, cerebral cortical grey matter volume, thickness, and surface area were assayed from MRI scans of 112, 3-year-old boys with ASD and 50 age-matched TD boys. The boys with ASD-DM (n = 17) were analyzed separately from the boys with normal brain size (ASD-N, n = 95). Previous studies of cortical thickness and surface area for ASD children in this age range have come to diametrically different conclusions concerning the significance of cortical thickness vs. surface area. Current analyses indicate that cortical thickness was comparable across the ASD and TD groups. However, surface area was significantly greater in the ASD group compared to the TD group. This result was driven largely by the children with ASD-DM. Even in the ASD-DM group, not all cortical regions demonstrated increased surface area. These results provide strong evidence that the early cortical overgrowth associated with ASD is due primarily to increased surface area and not to increased cortical thickness.

White matter tract signatures of impaired social cognition in frontotemporal lobar degeneration

Impairments of social cognition are often leading features in frontotemporal lobar degeneration (FTLD) and likely to reflect large-scale brain network disintegration. However, the neuroanatomical basis of impaired social cognition in FTLD and the role of white matter connections have not been defined. Here we assessed social cognition in a cohort of patients representing two core syndromes of FTLD, behavioural variant frontotemporal dementia (bvFTD; n = 29) and semantic variant primary progressive aphasia (svPPA; n = 15), relative to healthy older individuals (n = 37) using two components of the Awareness of Social Inference Test, canonical emotion identification and sarcasm identification. Diffusion tensor imaging (DTI) was used to derive white matter tract correlates of social cognition performance and compared with the distribution of grey matter atrophy on voxel-based morphometry. The bvFTD and svPPA groups showed comparably severe deficits for identification of canonical emotions and sarcasm, and these deficits were correlated with distributed and overlapping white matter tract alterations particularly affecting frontotemporal connections in the right cerebral hemisphere. The most robust DTI associations were identified in white matter tracts linking cognitive and evaluative processing with emotional responses: anterior thalamic radiation, fornix (emotion identification) and uncinate fasciculus (sarcasm identification). DTI associations of impaired social cognition were more consistent than corresponding grey matter associations. These findings delineate a brain network substrate for the social impairment that characterises FTLD syndromes. The findings further suggest that DTI can generate sensitive and functionally relevant indexes of white matter damage in FTLD, with potential to transcend conventional syndrome boundaries.

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Social cognition deficits define frontotemporal dementias but are poorly understood.

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We studied brain network correlates of sarcasm processing in these dementias with DTI.

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Sarcasm deficits were particularly linked to right frontotemporal tract changes.

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DTI generates functionally relevant metrics of white matter damage in these dementias.

Stress and the social brain: behavioural effects and neurobiological mechanisms

Stress often affects our social lives. When undergoing high-level or persistent stress, individuals frequently retract from social interactions and become irritable and hostile. Predisposition to antisocial behaviours - including social detachment and violence - is also modulated by early life adversity; however, the effects of early life stress depend on the timing of exposure and genetic factors. Research in animals and humans has revealed some of the structural, functional and molecular changes in the brain that underlie the effects of stress on social behaviour. Findings in this emerging field will have implications both for the clinic and for society.

Compensating for age limits through emotional crossmodal integration

Social interactions in daily life necessitate the integration of social signals from different sensory modalities. In the aging literature, it is well established that the recognition of emotion in facial expressions declines with advancing age, and this also occurs with vocal expressions. By contrast, crossmodal integration processing in healthy aging individuals is less documented. Here, we investigated the age-related effects on emotion recognition when faces and voices were presented alone or simultaneously, allowing for crossmodal integration. In this study, 31 young adults (M = 25.8 years) and 31 older adults (M = 67.2 years) were instructed to identify several basic emotions (happiness, sadness, anger, fear, disgust) and a neutral expression, which were displayed as visual (facial expressions), auditory (non-verbal affective vocalizations) or crossmodal (simultaneous, congruent facial and vocal affective expressions) stimuli. The results showed that older adults performed slower and worse than younger adults at recognizing negative emotions from isolated faces and voices. In the crossmodal condition, although slower, older adults were as accurate as younger except for anger. Importantly, additional analyses using the "race model" demonstrate that older adults benefited to the same extent as younger adults from the combination of facial and vocal emotional stimuli. These results help explain some conflicting results in the literature and may clarify emotional abilities related to daily life that are partially spared among older adults.

Face processing in autism spectrum disorders: From brain regions to brain networks

Autism spectrum disorder (ASD) is characterized by reduced attention to social stimuli including the human face. This hypo-responsiveness to stimuli that are engaging to typically developing individuals may result from dysfunctioning motivation, reward, and attention systems in the brain. Here we review an emerging neuroimaging literature that emphasizes a shift from focusing on hypo-activation of isolated brain regions such as the fusiform gyrus, amygdala, and superior temporal sulcus in ASD to a more holistic approach to understanding face perception as a process supported by distributed cortical and subcortical brain networks. We summarize evidence for atypical activation patterns within brain networks that may contribute to social deficits characteristic of the disorder. We conclude by pointing to gaps in the literature and future directions that will continue to shed light on aspects of face processing in autism that are still under-examined. In particular, we highlight the need for more developmental studies and studies examining ecologically valid and naturalistic social stimuli.

Folk explanations of behavior: a specialized use of a domain-general mechanism

People typically explain others' behaviors by attributing them to the beliefs and motives of an unobservable mind. Although such attributional inferences are critical for understanding the social world, it is unclear whether they rely on processes distinct from those used to understand the nonsocial world. In the present study, we used functional MRI to identify brain regions associated with making attributions about social and nonsocial situations. Attributions in both domains activated a common set of brain regions, and individual differences in the domain-specific recruitment of one of these regions--the dorsomedial prefrontal cortex (DMPFC)--correlated with attributional accuracy in each domain. Overall, however, the DMPFC showed greater activation for attributions about social than about nonsocial situations, and this selective response to the social domain was greatest in participants who reported the highest levels of social expertise. We conclude that folk explanations of behavior are an expert use of a domain-general cognitive ability.

Idiosyncratic brain activation patterns are associated with poor social comprehension in autism

Autism spectrum disorder (ASD) features profound social deficits but neuroimaging studies have failed to find any consistent neural signature. Here we connect these two facts by showing that idiosyncratic patterns of brain activation are associated with social comprehension deficits. Human participants with ASD (N = 17) and controls (N = 20) freely watched a television situation comedy (sitcom) depicting seminaturalistic social interactions ("The Office", NBC Universal) in the scanner. Intersubject correlations in the pattern of evoked brain activation were reduced in the ASD group-but this effect was driven entirely by five ASD subjects whose idiosyncratic responses were also internally unreliable. The idiosyncrasy of these five ASD subjects was not explained by detailed neuropsychological profile, eye movements, or data quality; however, they were specifically impaired in understanding the social motivations of characters in the sitcom. Brain activation patterns in the remaining ASD subjects were indistinguishable from those of control subjects using multiple multivariate approaches. Our findings link neurofunctional abnormalities evoked by seminaturalistic stimuli with a specific impairment in social comprehension, and highlight the need to conceive of ASD as a heterogeneous classification.

The primate amygdala in social perception - insights from electrophysiological recordings and stimulation

The role of the amygdala in emotion and social perception has been intensively investigated primarily through studies using functional magnetic resonance imaging (fMRI). Recently, this topic has been examined using single-unit recordings in both humans and monkeys, with a focus on face processing. The findings provide novel insights, including several surprises: amygdala neurons have very long response latencies, show highly nonlinear responses to whole faces, and can be exquisitely selective for very specific parts of faces such as the eyes. In humans, the responses of amygdala neurons correlate with internal states evoked by faces, rather than with their objective features. Current and future studies extend the investigations to psychiatric illnesses such as autism, in which atypical face processing is a hallmark of social dysfunction.

The marmoset monkey as a model for visual neuroscience

The common marmoset (Callithrix jacchus) has been valuable as a primate model in biomedical research. Interest in this species has grown recently, in part due to the successful demonstration of transgenic marmosets. Here we examine the prospects of the marmoset model for visual neuroscience research, adopting a comparative framework to place the marmoset within a broader evolutionary context. The marmoset's small brain bears most of the organizational features of other primates, and its smooth surface offers practical advantages over the macaque for areal mapping, laminar electrode penetration, and two-photon and optical imaging. Behaviorally, marmosets are more limited at performing regimented psychophysical tasks, but do readily accept the head restraint that is necessary for accurate eye tracking and neurophysiology, and can perform simple discriminations. Their natural gaze behavior closely resembles that of other primates, with a tendency to focus on objects of social interest including faces. Their immaturity at birth and routine twinning also makes them ideal for the study of postnatal visual development. These experimental factors, together with the theoretical advantages inherent in comparing anatomy, physiology, and behavior across related species, make the marmoset an excellent model for visual neuroscience.

Social neuroscience in psychiatry: unravelling the neural mechanisms of social dysfunction

Social neuroscience is a flourishing, interdisciplinary field that investigates the underlying biological processes of social cognition and behaviour. The recent application of social neuroscience to psychiatric research advances our understanding of various psychiatric illnesses that are characterized by impairments in social cognition and social functioning. In addition, the upcoming line of social neuroscience research provides new techniques to design and evaluate treatment interventions that are aimed at improving patients' social lives. This review provides a contemporary overview of social neuroscience in psychiatry. We draw together the major findings about the neural mechanisms of social cognitive processes directed at understanding others and social interactions in psychiatric illnesses and discuss their implications for future research and clinical practice.

Amygdala lesions do not compromise the cortical network for false-belief reasoning

The amygdala plays an integral role in human social cognition and behavior, with clear links to emotion recognition, trust judgments, anthropomorphization, and psychiatric disorders ranging from social phobia to autism. A central feature of human social cognition is a theory-of-mind (ToM) that enables the representation other people's mental states as distinct from one's own. Numerous neuroimaging studies of the best studied use of ToM--false-belief reasoning--suggest that it relies on a specific cortical network; moreover, the amygdala is structurally and functionally connected with many components of this cortical network. It remains unknown whether the cortical implementation of any form of ToM depends on amygdala function. Here we investigated this question directly by conducting functional MRI on two patients with rare bilateral amygdala lesions while they performed a neuroimaging protocol standardized for measuring cortical activity associated with false-belief reasoning. We compared patient responses with those of two healthy comparison groups that included 480 adults. Based on both univariate and multivariate comparisons, neither patient showed any evidence of atypical cortical activity or any evidence of atypical behavioral performance; moreover, this pattern of typical cortical and behavioral response was replicated for both patients in a follow-up session. These findings argue that the amygdala is not necessary for the cortical implementation of ToM in adulthood and suggest a reevaluation of the role of the amygdala and its cortical interactions in human social cognition.

Autism: reduced connectivity between cortical areas involved in face expression, theory of mind, and the sense of self

Whole-brain voxel-based unbiased resting state functional connectivity was analysed in 418 subjects with autism and 509 matched typically developing individuals. We identified a key system in the middle temporal gyrus/superior temporal sulcus region that has reduced cortical functional connectivity (and increased with the medial thalamus), which is implicated in face expression processing involved in social behaviour. This system has reduced functional connectivity with the ventromedial prefrontal cortex, which is implicated in emotion and social communication. The middle temporal gyrus system is also implicated in theory of mind processing. We also identified in autism a second key system in the precuneus/superior parietal lobule region with reduced functional connectivity, which is implicated in spatial functions including of oneself, and of the spatial environment. It is proposed that these two types of functionality, face expression-related, and of one's self and the environment, are important components of the computations involved in theory of mind, whether of oneself or of others, and that reduced connectivity within and between these regions may make a major contribution to the symptoms of autism.

Predictors of longitudinal outcome and recovery of pragmatic language and its relation to externalizing behaviour after pediatric traumatic brain injury

The purpose of the present investigation was to evaluate the contribution of age-at-insult and brain pathology on longitudinal outcome and recovery of pragmatic language in a sample of children and adolescents with traumatic brain injury (TBI). Children and adolescents with mild to severe TBI (n=112) were categorized according to timing of brain insult: (i) Middle Childhood (5-9 years; n=41); (ii) Late Childhood (10-11 years; n=39); and (iii) Adolescence (12-15 years; n=32) and group-matched for age, gender and socio-economic status (SES) to a typically developing (TD) control group (n=43). Participants underwent magnetic resonance imaging (MRI) including a susceptibility weighted imaging (SWI) sequence 2-8 weeks after injury and were assessed on measures of pragmatic language and behavioural functioning at 6- and 24-months after injury. Children and adolescents with TBI of all severity levels demonstrated impairments in these domains at 6-months injury before returning to age-expected levels at 2-years post-TBI. However, while adolescent TBI was associated with post-acute disruption to skills that preceded recovery to age-expected levels by 2-years post injury, the middle childhood TBI group demonstrated impairments at 6-months post-injury that were maintained at 2-year follow up. Reduced pragmatic communication was associated with frontal, temporal and corpus callosum lesions, as well as more frequent externalizing behaviour at 24-months post injury. Findings show that persisting pragmatic language impairment after pediatric TBI is related to younger age at brain insult, as well as microhemorrhagic pathology in brain regions that contribute to the anatomically distributed social brain network. Relationships between reduced pragmatic communication and more frequent externalizing behavior underscore the need for context-sensitive rehabilitation programs that aim to increase interpersonal effectiveness and reduce risk for maladaptive behavior trajectories into the long-term post injury.

Stereological study of pyramidal neurons in the human superior temporal gyrus from childhood to adulthood

The association cortex of the superior temporal gyrus (STG) is implicated in complex social and linguistic functions. Thus, reliable methods for quantifying cellular variation in this region could greatly benefit researchers interested in addressing the cellular correlates of typical and atypical function associated with these critical cognitive abilities. To facilitate this task, we first present a general set of cytoarchitectonic criteria targeted specifically toward stereological analyses of thick, Nissl-stained sections for the homotypical cortex of the STG, referred to here as BA22/TA. Second, we use the optical fractionator to estimate pyramidal neuron number and the nucleator for pyramidal somal and nuclear volume. We also investigated the influence of age and sex on these parameters, as well as set a typically developing baseline for future comparisons. In 11 typically developing cases aged 4-48 years, the most distinguishing features of BA22/TA were the presence of distinct granular layers, a prominent, jagged layer IIIc, and a distinctly staining VIa. The average number of neurons was 91 ± 15 million, the volume of pyramidal soma 1,512 µm(3) , and the nuclear volume 348 µm(3) . We found no correlation with age and neuron number. In contrast, pyramidal somal and nuclear volume were both negatively correlated and linearly associated with age in regression analyses. We found no significant sex differences. Overall, the data support the idea that postnatal neuron numbers are relatively stable through development but also suggest that neuronal volume may be subject to important developmental variation. Both measures are critical variables in the study of developmental neuropathology.

A disconnection account of subjective empathy impairments in diffuse low-grade glioma patients

Human empathic experience is a multifaceted psychological construct which arises from functional integration of multiple neural networks. Despite accumulating knowledge about the cortical circuitry of empathy, almost nothing is known about the connectivity that may be concerned in conveying empathy-related neural information. To bridge this gap in knowledge, we studied dispositional empathy in a large-sized cohort of 107 patients who had undergone surgery for a diffuse low-grade glioma. The self-report questionnaire used enabled us to obtain a global measure of subjective empathy but also, importantly, to assess the two main components of empathy (cognitive and emotional). Data were processed by combining voxelwise and tractwise lesion-symptom analyses. Several major findings emerged from our analyses. First of all, topological voxelwise analyses were inconclusive. Conversely, tractwise multiple regression analyses, including all major associative white matter pathways as potential predictors, yielded to significant models explaining substantial part of the behavioural variance. Among the main results, we found that disconnection of the left cingulum bundle was a strong predictor of a low cognitive empathy (p<0.0005 Bonferroni-corrected). Similarly, we found that disconnection of the right uncinate fasciculus and the right inferior fronto-occipital fasciculus predicted, respectively, a low (p<0.05 Bonferroni-corrected) and a high (p<0.05 Bonferroni-corrected) subjective empathy. Finally, although we failed to relate emotional empathy to disruption of a specific tract, correlation analyses indicated a positive association between this component of empathy and the volumes of residual lesion infiltration in the right hemisphere (p<0.01). Taken as a whole, these findings provide key fundamental insights into the anatomical connectivity of empathy. They may help to better understand the pathophysiology of empathy impairments in pathological conditions characterized by abnormalities of long-range anatomical connectivity, such as autism spectrum disorders, schizophrenia and fronto-temporal dementia.

An integrative neural model of social perception, action observation, and theory of mind

In the field of social neuroscience, major branches of research have been instrumental in describing independent components of typical and aberrant social information processing, but the field as a whole lacks a comprehensive model that integrates different branches. We review existing research related to the neural basis of three key neural systems underlying social information processing: social perception, action observation, and theory of mind. We propose an integrative model that unites these three processes and highlights the posterior superior temporal sulcus (pSTS), which plays a central role in all three systems. Furthermore, we integrate these neural systems with the dual system account of implicit and explicit social information processing. Large-scale meta-analyses based on Neurosynth confirmed that the pSTS is at the intersection of the three neural systems. Resting-state functional connectivity analysis with 1000 subjects confirmed that the pSTS is connected to all other regions in these systems. The findings presented in this review are specifically relevant for psychiatric research especially disorders characterized by social deficits such as autism spectrum disorder.

The Programming of the Social Brain by Stress During Childhood and Adolescence: From Rodents to Humans

The quality and quantity of social experience is fundamental to an individual's health and well-being. Early life stress is known to be an important factor in the programming of the social brain that exerts detrimental effects on social behaviors. The peri-adolescent period, comprising late childhood and adolescence, represents a critical developmental window with regard to the programming effects of stress on the social brain. Here, we discuss social behavior and the physiological and neurobiological consequences of stress during peri-adolescence in the context of rodent paradigms that model human adversity, including social neglect and isolation, social abuse, and exposure to fearful experiences. Furthermore, we discuss peri-adolescent stress as a potent component that influences the social behaviors of individuals in close contact with stressed individuals and that can also influence future generations. We also discuss the temporal dynamics programmed by stress on the social brain and debate whether social behavior alterations are adaptive or maladaptive. By revising the existing literature and defining open questions, we aim to expand the framework in which interactions among peri-adolescent stress, the social brain, and behavior can be better conceptualized.

Assessing and Stabilizing Aberrant Neuroplasticity in Autism Spectrum Disorder: The Potential Role of Transcranial Magnetic Stimulation

Exciting developments have taken place in the neuroscience research in autism spectrum disorder (ASD), and results from these studies indicate that brain in ASD is associated with aberrant neuroplasticity. Transcranial magnetic stimulation (TMS) has rapidly evolved to become a widely used, safe, and non-invasive neuroscientific tool to investigate a variety of neurophysiological processes, including neuroplasticity. The diagnostic and therapeutic potential of TMS in ASD is beginning to be realized. In this article, we briefly reviewed evidence of aberrant neuroplasticity in ASD, suggested future directions in assessing neuroplasticity using repetitive TMS (rTMS), and discussed the potential of rTMS in rectifying aberrant neuroplasticity in ASD.

e-HCL-32: a useful, valid and user friendly tool in the screening of bipolar II disorder

BACKGROUND AND OBJECTIVES

Bipolar type II (BDII) is a frequent disorder with high morbidity and mortality, characterized by depressive and hypomanic episodes. Early diagnosis can be effective in improving long-term prognosis. However, diagnosing BDII is challenging due to the difficulty in detecting past hypomanic episodes. The HCL-32 is a widely used and reliable screening instrument for the detection of past hypomanic episodes. Making this tool available to more patients could help diagnose and treat undetected cases of BDII earlier. New technologies such as the Internet have been previously used for this purpose with favorable outcomes. Accordingly, the objective of this study is to evaluate the acceptability, validity, reliability and equivalence of an online version of this questionnaire.

METHODS

From May 2012 to March 2013, 52 participants attending an outpatient mental health clinic completed a paper version of the HCL-32 (HCL-32) and its online version (e-HCL-32) within two weeks. After its completion, they were asked to answer a brief satisfaction survey.

RESULTS

No differences were found (HCL-32 mean total score=17.73 (SD=7.37), e-HCL-32 mean total score=18.28 (SD=7.09). T=-1.720, p=0.092, 95% CI=-1.21 to 0.09) between the results of the paper and pencil HCL-32 compared to its online version (e-HCL-32). The psychometric properties of the online version of the hypomania checklist (e-HCL-32) were good and comparable to the paper and pencil version. 80% of participants found online questionnaires to be easier to answer and more user-friendly.

CONCLUSION

The results of this study support the use of an online screening tool for the detection of previous hypomanic episodes (necessary for BDII diagnosis) as it showed to have a similar validity and reliability to the traditional paper and pencil method.

The emergence of age-dependent social cognitive deficits after generalized insult to the developing brain: a longitudinal prospective analysis using susceptibility-weighted imaging

Childhood and adolescence are critical periods for maturation of neurobiological processes that underlie complex social and emotional behavior including Theory of Mind (ToM). While structural correlates of ToM are well described in adults, less is known about the anatomical regions subsuming these skills in the developing brain or the impact of cerebral insult on the acquisition and establishment of high-level social cognitive skills. This study aimed to examine the differential influence of age-at-insult and brain pathology on ToM in a sample of children and adolescents with traumatic brain injury (TBI). Children and adolescents with TBI (n = 112) were categorized according to timing of brain insult: (i) middle childhood (5-9 years; n = 41); (ii) late childhood (10-11 years; n = 39); and (iii) adolescence (12-15 years; n = 32) and group-matched for age, gender, and socioeconomic status to a typically developing (TD) control group (n = 43). Participants underwent magnetic resonance imaging including a susceptibility-weighted imaging (SWI) sequence 2-8 weeks postinjury and were assessed on a battery of ToM tasks at 6- and 24-months after injury. Results showed that for adolescents with TBI, social cognitive dysfunction at 6- and 24-months postinjury was associated with diffuse neuropathology and a greater number of lesions detected using SWI. In the late childhood TBI group, we found a time-dependent emergence of social cognitive impairment, linked to diffuse neuropathology. The middle childhood TBI group demonstrated performance unrelated to SWI pathology and comparable to TD controls. Findings indicate that the full extent of social cognitive deficits may not be realized until the associated skills reach maturity. Evidence for brain structure-function relationships suggests that the integrity of an anatomically distributed network of brain regions and their connections is necessary for the acquisition and establishment of high-level social cognitive skills.

Spatio-temporal dynamics of kind versus hostile intentions in the human brain: An electrical neuroimaging study

Neuroscience research suggests that inferring neutral intentions of other people recruits a specific brain network within the inferior fronto-parietal action observation network as well as a putative social network including brain areas subserving theory of mind, such as the posterior superior temporal sulcus (pSTS), the temporo-parietal junction (TPJ), and also the anterior cingulate cortex (ACC). Recent studies on harmful intentions have refined this network by showing the specific involvement of the ACC, amygdala, and ventromedial prefrontal cortex (vmPFC) in early stages (within 200 ms) of information processing. However, the functional dynamics for kind intentions within and among these networks remains unclear. To address this question, we measured electrical brain activity from 18 healthy adult participants while they were performing an intention inference task with three different types of intentions: kind, hostile and non-interactive. Electrophysiological results revealed that kind intentions were characterized by significantly larger peak amplitudes of N2 over the frontal sites than those for hostile and non-interactive intentions. On the other hand, there were no significant differences between hostile and non-interactive intentions at N2. The source analysis suggested that the vicinity of the left cingulate gyrus contributed to the N2 effect by subtracting the kindness condition from the non-interactive condition within 250-350 ms. At a later stage (i.e., during the 270-500 ms epoch), the peak amplitude of the P3 over the parietal sites and the right hemisphere was significantly larger for hostile intentions compared to the kind and non-interactive intentions. No significant differences were observed at P3 between kind and non-interactive intentions. The source analysis showed that the vicinity of the left anterior cingulate cortex contributed to the P3 effect by subtracting the hostility condition from the non-interactive condition within 450-550 ms. The present study provides preliminary evidence of the spatio-temporal dynamics sustaining the dissociation between the understandings of different types of social intentions.

Empathy and contextual social cognition

Empathy is a highly flexible and adaptive process that allows for the interplay of prosocial behavior in many different social contexts. Empathy appears to be a very situated cognitive process, embedded with specific contextual cues that trigger different automatic and controlled responses. In this review, we summarize relevant evidence regarding social context modulation of empathy for pain. Several contextual factors, such as stimulus reality and personal experience, affectively link with other factors, emotional cues, threat information, group membership, and attitudes toward others to influence the affective, sensorimotor, and cognitive processing of empathy. Thus, we propose that the frontoinsular-temporal network, the so-called social context network model (SCNM), is recruited during the contextual processing of empathy. This network would (1) update the contextual cues and use them to construct fast predictions (frontal regions), (2) coordinate the internal (body) and external milieus (insula), and (3) consolidate the context-target associative learning of empathic processes (temporal sites). Furthermore, we propose these context-dependent effects of empathy in the framework of the frontoinsular-temporal network and examine the behavioral and neural evidence of three neuropsychiatric conditions (Asperger syndrome, schizophrenia, and the behavioral variant of frontotemporal dementia), which simultaneously present with empathy and contextual integration impairments. We suggest potential advantages of a situated approach to empathy in the assessment of these neuropsychiatric disorders, as well as their relationship with the SCNM.

Modulating functional and dysfunctional mentalizing by transcranial magnetic stimulation

Mentalizing, the ability to attribute mental states to others and oneself, is a cognitive function with high relevance for social interactions. Recent neuroscientific research has increasingly contributed to attempts to decompose this complex social cognitive function into constituting neurocognitive building blocks. Additionally, clinical research that focuses on social cognition to find links between impaired social functioning and neurophysiological deviations has accumulated evidence that mentalizing is affected in most psychiatric disorders. Recently, both lines of research have started to employ transcranial magnetic stimulation: the first to modulate mentalizing in order to specify its neurocognitive components, the latter to treat impaired mentalizing in clinical conditions. This review integrates findings of these two different approaches to draw a more detailed picture of the neurocognitive basis of mentalizing and its deviations in psychiatric disorders. Moreover, we evaluate the effectiveness of hitherto employed stimulation techniques and protocols, paradigms and outcome measures. Based on this overview we highlight new directions for future research on the neurocognitive basis of functional and dysfunctional social cognition.

Anatomical likelihood estimation meta-analysis of grey and white matter anomalies in autism spectrum disorders

Autism spectrum disorders (ASD) are characterized by impairments in social communication and restrictive, repetitive behaviors. While behavioral symptoms are well-documented, investigations into the neurobiological underpinnings of ASD have not resulted in firm biomarkers. Variability in findings across structural neuroimaging studies has contributed to difficulty in reliably characterizing the brain morphology of individuals with ASD. These inconsistencies may also arise from the heterogeneity of ASD, and wider age-range of participants included in MRI studies and in previous meta-analyses. To address this, the current study used coordinate-based anatomical likelihood estimation (ALE) analysis of 21 voxel-based morphometry (VBM) studies examining high-functioning individuals with ASD, resulting in a meta-analysis of 1055 participants (506 ASD, and 549 typically developing individuals). Results consisted of grey, white, and global differences in cortical matter between the groups. Modeled anatomical maps consisting of concentration, thickness, and volume metrics of grey and white matter revealed clusters suggesting age-related decreases in grey and white matter in parietal and inferior temporal regions of the brain in ASD, and age-related increases in grey matter in frontal and anterior-temporal regions. White matter alterations included fiber tracts thought to play key roles in information processing and sensory integration. Many current theories of pathobiology ASD suggest that the brains of individuals with ASD may have less-functional long-range (anterior-to-posterior) connections. Our findings of decreased cortical matter in parietal-temporal and occipital regions, and thickening in frontal cortices in older adults with ASD may entail altered cortical anatomy, and neurodevelopmental adaptations.

Emotion recognition and cognitive empathy deficits in adolescent offenders revealed by context-sensitive tasks

Emotion recognition and empathy abilities require the integration of contextual information in real-life scenarios. Previous reports have explored these domains in adolescent offenders (AOs) but have not used tasks that replicate everyday situations. In this study we included ecological measures with different levels of contextual dependence to evaluate emotion recognition and empathy in AOs relative to non-offenders, controlling for the effect of demographic variables. We also explored the influence of fluid intelligence (FI) and executive functions (EFs) in the prediction of relevant deficits in these domains. Our results showed that AOs exhibit deficits in context-sensitive measures of emotion recognition and cognitive empathy. Difficulties in these tasks were neither explained by demographic variables nor predicted by FI or EFs. However, performance on measures that included simpler stimuli or could be solved by explicit knowledge was either only partially affected by demographic variables or preserved in AOs. These findings indicate that AOs show contextual social-cognition impairments which are relatively independent of basic cognitive functioning and demographic variables.

Functional cortical network in alpha band correlates with social bargaining

Solving demanding tasks requires fast and flexible coordination among different brain areas. Everyday examples of this are the social dilemmas in which goals tend to clash, requiring one to weigh alternative courses of action in limited time. In spite of this fact, there are few studies that directly address the dynamics of flexible brain network integration during social interaction. To study the preceding, we carried out EEG recordings while subjects played a repeated version of the Ultimatum Game in both human (social) and computer (non-social) conditions. We found phase synchrony (inter-site-phase-clustering) modulation in alpha band that was specific to the human condition and independent of power modulation. The strength and patterns of the inter-site-phase-clustering of the cortical networks were also modulated, and these modulations were mainly in frontal and parietal regions. Moreover, changes in the individuals' alpha network structure correlated with the risk of the offers made only in social conditions. This correlation was independent of changes in power and inter-site-phase-clustering strength. Our results indicate that, when subjects believe they are participating in a social interaction, a specific modulation of functional cortical networks in alpha band takes place, suggesting that phase synchrony of alpha oscillations could serve as a mechanism by which different brain areas flexibly interact in order to adapt ongoing behavior in socially demanding contexts.

The effects of context processing on social cognition impairments in adults with Asperger's syndrome

Social cognition—the basis of all communicative and otherwise interpersonal relationships—is embedded in specific contextual circumstances which shape intrinsic meanings. This domain is compromised in the autism spectrum disorders (ASDs), including Asperger's syndrome (AS) (DSM-V). However, the few available reports of social cognition skills in adults with AS have largely neglected the effects of contextual factors. Moreover, previous studies on this population have also failed to simultaneously (a) assess multiple social cognition domains, (b) examine executive functions, (c) follow strict sample selection criteria, and (d) acknowledge the cognitive heterogeneity typical of the disorder. The study presently reviewed (Baez et al., 2012), addressed all these aspects in order to establish the basis of social cognition deficits in adult AS patients. Specifically, we assessed the performance of AS adults in multiple social cognition tasks with different context-processing requirements. The results suggest that social cognition deficits in AS imply a reduced ability to implicitly encode and integrate contextual cues needed to access social meaning. Nevertheless, the patients' performance was normal when explicit social information was presented or when the situation could be navigated with abstract rules. Here, we review the results of our study and other relevant data, and discuss their implications for the diagnosis and treatment of AS and other neuropsychiatric conditions (e.g., schizophrenia, bipolar disorder, frontotemporal dementia). Finally, we analyze previous results in the light of a current neurocognitive model of social-context processing.