Social cognition, the male brain and the autism spectrum

Sex differences in brain functional specialization and interhemispheric cooperation among children with autism spectrum disorders

The prevalence of autism spectrum disorders (ASDs) differs substantially between males and females, suggesting that sex-related neurodevelopmental factors are central to ASD pathogenesis. Numerous studies have suggested that abnormal brain specialization patterns and poor regional cooperation contribute to ASD pathogenesis, but relatively little is known about the related sex differences. Therefore, this study examined sex differences in brain functional specialization and cooperation among children with ASD. The autonomy index (AI) and connectivity between functionally homotopic voxels (CFH) derived from resting-state functional magnetic resonance imaging (rs-fMRI) were compared between 58 male and 13 female children with ASD. In addition, correlations were examined between regional CFH values showing significant sex differences and symptom scores on the autism behavior checklist (ABC) and childhood autism rating scale (CARS). Male children with ASD demonstrated significantly greater CFH in the left fusiform gyrus (FG) and right opercular part of the inferior frontal gyrus (IFGoperc) than female children with ASD. In addition, the CFH value of the left FG in male children with ASD was negatively correlated with total ABC score and subscale scores for sensory and social abilities. In contrast, no sex differences were detected in brain specialization. These regional abnormalities in interhemispheric cooperation among male children with ASD may provide clues to the neural mechanisms underlying sex differences in ASD symptomatology and prevalence. Autism spectrum disorders, sex, resting-state functional magnetic resonance imaging, cerebral specialization, interhemispheric cooperation.

Exploring Gender Differences in the Instructor Presence Effect in Video Lectures: An Eye-Tracking Study

The instructor's presence on the screen has become a popular feature in the video lectures of online learning and has drawn increasing research interest. Studies on the instructor presence effect of video lectures mainly focused on the features of the instructor, and few have taken learners' differences, such as gender, into consideration. The current study examined whether male and female learners differed in their learning performance and eye movement features when learning video lectures with and without the instructor's presence. All participants (N = 64) were asked to watch three different types of video lectures: audio-video without instructor presence (AV), picture-video with instructor presence (PV), and video-video with instructor presence (VV). They watched nine videos, three of each condition, and completed a reading comprehension test after each video. Their eye movement data were simultaneously collected when they watched these videos. Results showed that learners gained better outcomes after watching the videos with a talking instructor (VV) than those with the instructor's picture (PV) or without the instructor (AV). This finding suggests that the dynamic presence of the instructor in video lectures could enhance learning through increased social presence and agency. Gender differences were found in their attention allocation, but not behavioral learning performance. When watching the videos with a talking instructor (VV), female learners dwelt longer on the instructor, while males transited more between the instructor and the text. Our results highlight the value of instructor presence in video lectures and call for more comprehensive explorations of gender differences in online learning outcomes and attention distribution.

Establishing a role of the semantic control network in social cognitive processing: A meta-analysis of functional neuroimaging studies

The contribution and neural basis of cognitive control is under-specified in many prominent models of socio-cognitive processing. Important outstanding questions include whether there are multiple, distinguishable systems underpinning control and whether control is ubiquitously or selectively engaged across different social behaviours and task demands. Recently, it has been proposed that the regulation of social behaviours could rely on brain regions specialised in the controlled retrieval of semantic information, namely the anterior inferior frontal gyrus (IFG) and posterior middle temporal gyrus. Accordingly, we investigated for the first time whether the neural activation commonly found in social functional neuroimaging studies extends to these 'semantic control' regions. We conducted five coordinate-based meta-analyses to combine results of 499 fMRI/PET experiments and identified the brain regions consistently involved in semantic control, as well as four social abilities: theory of mind, trait inference, empathy and moral reasoning. This allowed an unprecedented parallel review of the neural networks associated with each of these cognitive domains. The results confirmed that the anterior left IFG region involved in semantic control is reliably engaged in all four social domains. This supports the hypothesis that social cognition is partly regulated by the neurocognitive system underpinning semantic control.

Sex effects on cortical morphological networks in healthy young adults

Understanding sex-related differences across the human cerebral cortex is an important step in elucidating the basis of psychological, behavioural and clinical differences between the sexes. Prior structural neuroimaging studies primarily focused on regional sex differences using univariate analyses. Here we focus on sex differences in cortical morphological networks (CMNs) derived using multivariate modelling of regional cortical measures of volume and surface from high-quality structural MRI scans from healthy participants in the Human Connectome Project (HCP) (n = 1,063) and the Southwest University Longitudinal Imaging Multimodal (SLIM) study (n = 549). The functional relevance of the CMNs was inferred using the NeuroSynth decoding function. Sex differences were widespread but not uniform. In general, females had higher volume, thickness and cortical folding in networks that involve prefrontal (both ventral and dorsal regions including the anterior cingulate) and parietal regions while males had higher volume, thickness and cortical folding in networks that primarily include temporal and posterior cortical regions. CMN loading coefficients were used as input features to linear discriminant analyses that were performed separately in the HCP and SLIM; sex was predicted with a high degree of accuracy (81%-85%) across datasets. The availability of behavioral data in the HCP enabled us to show that male-biased surface-based CMNs were associated with externalizing behaviors. These results extend previous literature on regional sex-differences by identifying CMNs that can reliably predict sex, are relevant to the expression of psychopathology and provide the foundation for the future investigation of their functional significance in clinical populations.

Neurobiological mechanisms of social cognition treatment in high-functioning adults with autism spectrum disorder

BACKGROUND

The promise of precision medicine for autism spectrum disorder (ASD) hinges on developing neuroscience-informed individualized interventions. Taking an important step in this direction, we investigated neuroplasticity in response to an ecologically-valid, computer-based social-cognitive training (SCOTT).

METHODS

In an active control group design, 48 adults with ASD were randomly assigned to a 3-month SCOTT or non-social computer training. Participants completed behavioral tasks, a functional and structural magnetic resonance imaging session before and after the training period.

RESULTS

The SCOTT group showed social-cognitive improvements on close and distant generalization tasks. The improvements scaled with reductions in functional activity and increases in cortical thickness in prefrontal regions.

CONCLUSION

In sum, we provide evidence for the sensitivity of neuroscientific methods to reflect training-induced social-cognitive improvements in adults with ASD. These results encourage the use of neuroimaging data to describe and quantify treatment-related changes more broadly.

Multimodal Affective State Assessment Using fNIRS + EEG and Spontaneous Facial Expression

Human facial expressions are regarded as a vital indicator of one's emotion and intention, and even reveal the state of health and wellbeing. Emotional states have been associated with information processing within and between subcortical and cortical areas of the brain, including the amygdala and prefrontal cortex. In this study, we evaluated the relationship between spontaneous human facial affective expressions and multi-modal brain activity measured via non-invasive and wearable sensors: functional near-infrared spectroscopy (fNIRS) and electroencephalography (EEG) signals. The affective states of twelve male participants detected via fNIRS, EEG, and spontaneous facial expressions were investigated in response to both image-content stimuli and video-content stimuli. We propose a method to jointly evaluate fNIRS and EEG signals for affective state detection (emotional valence as positive or negative). Experimental results reveal a strong correlation between spontaneous facial affective expressions and the perceived emotional valence. Moreover, the affective states were estimated by the fNIRS, EEG, and fNIRS + EEG brain activity measurements. We show that the proposed EEG + fNIRS hybrid method outperforms fNIRS-only and EEG-only approaches. Our findings indicate that the dynamic (video-content based) stimuli triggers a larger affective response than the static (image-content based) stimuli. These findings also suggest joint utilization of facial expression and wearable neuroimaging, fNIRS, and EEG, for improved emotional analysis and affective brain-computer interface applications.

Distinct effects of social motivation on face evaluations in adolescents with and without autism

Individual differences in social motivation have an influence on many behaviours in both clinical and non-clinical populations. As such, social motivation has been identified as a biological trait that is particularly well-suited for dimensional approaches cutting across neuropsychological conditions. In the present paper, we tested whether social motivation had a similar impact in the general population and in a neuropsychological condition characterized by diminished social motivation: Autism Spectrum Disorders (ASD). More precisely, we evaluated the effect of social motivation on face evaluations in 20 adolescents with ASD and 20 matched controls using avatars parametrically varying in dominance and trustworthiness. In line with previous research, we found in the control group that participants with higher levels of social motivation relied more on perceived trustworthiness when producing likeability judgments. However, this pattern was not found in the ASD group. Social motivation thus appears to have a different effect in ASD and control populations, which raises questions about the relevance of subclinical or non-clinical populations to understand ASD.

Chinese Norms for the Autism Spectrum Rating Scale

This study aimed to establish norms for the modified Chinese version of the Autism Spectrum Rating Scale (ASRS). Participants were recruited from Shanghai, Harbin, Guangzhou, and Changsha, China, and their parents and teachers were invited to complete the Chinese Parent version and the Teacher version of the ASRS. In both versions, boys had significantly higher sub-scale scores and total score (T-score) by 1–3 and 4–5 points respectively, than girls (both P < 0.001). Age had weak correlations with some sub-scores and the T-score (r ranged from −0.1859 to 0.0738), and some reached significance (P < 0.03). The correlations appeared stronger and were more common in females. The T-score based on Chinese norms ideally correlated with the score based on the United States norms in boys and girls for both versions. Norms for the Chinese version of the ASRS for children aged 6–12 years are proposed and may be helpful for screening individuals with autism spectrum disorders from the general population of children.

The Structural and Functional Organization of Cognition

This article proposes that what have been historically and contemporarily defined as different domains of human cognition are served by one of four functionally- and structurally-distinct areas of the prefrontal cortex (PFC). Their contributions to human intelligence are as follows: (a) BA9, enables our emotional intelligence, engaging the psychosocial domain; (b) BA47, enables our practical intelligence, engaging the material domain; (c) BA46 (or BA46-9/46), enables our abstract intelligence, engaging the hypothetical domain; and (d) BA10, enables our temporal intelligence, engaging in planning within any of the other three domains. Given their unique contribution to human cognition, it is proposed that these areas be called the, social (BA9), material (BA47), abstract (BA46-9/46) and temporal (BA10) mind. The evidence that BA47 participates strongly in verbal and gestural communication suggests that language evolved primarily as a consequence of the extreme selective pressure for practicality; an observation supported by the functional connectivity between BA47 and orbital areas that negatively reinforce lying. It is further proposed that the abstract mind (BA46-9/46) is the primary seat of metacognition charged with creating adaptive behavioral strategies by generating higher-order concepts (hypotheses) from lower-order concepts originating from the other three domains of cognition.

Effects of sex and DTNBP1 (dysbindin) null gene mutation on the developmental GluN2B-GluN2A switch in the mouse cortex and hippocampus

BACKGROUND

Neurodevelopmental disorders such as autism spectrum disorders and schizophrenia differentially impact males and females and are highly heritable. The ways in which sex and genetic vulnerability influence the pathogenesis of these disorders are not clearly understood. The n-methyl-d-aspartate (NMDA) receptor pathway has been implicated in schizophrenia and autism spectrum disorders and changes dramatically across postnatal development at the level of the GluN2B-GluN2A subunit "switch" (a shift from reliance on GluN2B-containing receptors to reliance on GluN2A-containing receptors). We investigated whether sex and genetic vulnerability (specifically, null mutation of DTNBP1 [dysbindin; a possible susceptibility gene for schizophrenia]) influence the developmental GluN2B-GluN2A switch.

METHODS

Subcellular fractionation to enrich for postsynaptic density (PSD), together with Western blotting and kinase assay, were used to investigate the GluN2B-GluN2A switch in the cortex and hippocampus of male and female DTNBP1 null mutant mice and their wild-type littermates. Main effects of sex and DTNBP1 genotype, and interactions with age, were assessed using factorial ANOVA.

RESULTS

Sex differences in the GluN2B-GluN2A switch emerged across development at the frontal cortical synapse, in parameters related to GluN2B. Males across genotypes displayed higher GluN2B:GluN2A and GluN2B:GluN1 ratios (p < 0.05 and p < 0.01, respectively), higher GluN2B phosphorylation at Y1472 (p < 0.01), and greater abundance of PLCγ (p < 0.01) and Fyn (p = 0.055) relative to females. In contrast, effects of DTNBP1 were evident exclusively in the hippocampus. The developmental trajectory of GluN2B was disrupted in DTNBP1 null mice (genotype × age interaction p < 0.05), which also displayed an increased synaptic GluN2A:GluN1 ratio (p < 0.05) and decreased PLCγ (p < 0.05) and Fyn (only in females; p < 0.0005) compared to wild-types.

CONCLUSIONS

Sex and DTNBP1 mutation influence the GluN2B-GluN2A switch at the synapse in a brain-region-specific fashion involving pY1472-GluN2B, Fyn, and PLCγ. This highlights the possible mechanisms through which risk factors may mediate their effects on vulnerability to disorders of NMDA receptor dysfunction.

A Spatiotemporal Profile of In Vivo Cerebral Blood Flow Changes Following Intranasal Oxytocin in Humans

BACKGROUND

Animal and human studies highlight the role of oxytocin in social cognition and behavior and the potential of intranasal oxytocin (IN-OT) to treat social impairment in individuals with neuropsychiatric disorders such as autism. However, extensive efforts to evaluate the central actions and therapeutic efficacy of IN-OT may be marred by the absence of data regarding its temporal dynamics and sites of action in the living human brain.

METHODS

In a placebo-controlled study, we used arterial spin labeling to measure IN-OT-induced changes in resting regional cerebral blood flow (rCBF) in 32 healthy men. Volunteers were blinded regarding the nature of the compound they received. The rCBF data were acquired 15 min before and up to 78 min after onset of treatment onset (40 IU of IN-OT or placebo). The data were analyzed using mass univariate and multivariate pattern recognition techniques.

RESULTS

We obtained robust evidence delineating an oxytocinergic network comprising regions expected to express oxytocin receptors, based on histologic evidence, and including core regions of the brain circuitry underpinning social cognition and emotion processing. Pattern recognition on rCBF maps indicated that IN-OT-induced changes were sustained over the entire posttreatment observation interval (25-78 min) and consistent with a pharmacodynamic profile showing a peak response at 39-51 min.

CONCLUSIONS

Our study provides the first visualization and quantification of IN-OT-induced changes in rCBF in the living human brain unaffected by cognitive, affective, or social manipulations. Our findings can inform theoretical and mechanistic models regarding IN-OT effects on typical and atypical social behavior and guide future experiments (e.g., regarding the timing of experimental manipulations).

Reduced cortical thickness and its association with social reactivity in children with autism spectrum disorder

Symptomatology and behavioral characteristics in autism spectrum disorders (ASD) have increasingly been linked to abnormalities in early brain growth patterns of affected children. Studies investigating specific components of gray matter structure, such as cortical thickness (CT), have produced conflicting results, and have rarely included additional measures of social impairment. In the present study, we applied a surface-based whole brain analysis to investigate CT in a sample of 36 pre-adolescent children [18 subjects with ASD (IQ mean: 111) and 18 healthy controls (IQ mean: 112.8), age range 6-12 years]. The CT analysis revealed widespread, but mostly left-hemispheric thinning in frontal, temporal, parietal and occipital brain areas related to the theory-of-mind network and the heteromodal association cortex. In an exploratory analysis, CT was observed to be differently associated with social impairment in children with ASD compared with typically developing children. The affected neuroanatomical regions are related to characteristic deficits in language, cognition and behavior that are often observed in the disorder. The relationship between social impairment and CT in children with ASD and controls seems to indicate aberrant developmental trajectories in ASD emerging early in life.

Neurobiological correlates in forensic assessment: a systematic review

BACKGROUND

With the increased knowledge of biological risk factors, interest in including this information in forensic assessments is growing. Currently, forensic assessments are predominantly focused on psychosocial factors. A better understanding of the neurobiology of violent criminal behaviour and biological risk factors could improve forensic assessments.

OBJECTIVE

To provide an overview of the current evidence about biological risk factors that predispose people to antisocial and violent behaviour, and determine its usefulness in forensic assessment.

METHODS

A systematic literature search was conducted using articles from PsycINFO, Embase and Pubmed published between 2000 and 2013.

RESULTS

This review shows that much research on the relationship between genetic predisposition and neurobiological alterations with aggression is performed on psychiatric patients or normal populations. However, the number of studies comparing offenders is limited. There is still a great need to understand how genetic and neurobiological alterations and/or deficits are related to violent behaviour, specifically criminality. Most studies focus on only one of the genetic or neurobiological fields related to antisocial and/or violent behaviour. To reliably correlate the findings of these fields, a standardization of methodology is urgently needed.

CONCLUSION

Findings from the current review suggest that violent aggression, like all forms of human behaviour, both develops under specific genetic and environmental conditions, and requires interplay between these conditions. Violence should be considered as the end product of a chain of life events, during which risks accumulate and potentially reinforce each other, displaying or triggering a specific situation. This systematic review did not find evidence of predispositions or neurobiological alterations that solely explain antisocial or violent behaviour. With better designed studies, more correlation between diverse fields, and more standardisation, it might be possible to elucidate underlying mechanisms. Thus, we advocate maintaining the current case-by-case differentiated approach to evidence-based forensic assessment.

Biological sex affects the neurobiology of autism

In autism, heterogeneity is the rule rather than the exception. One obvious source of heterogeneity is biological sex. Since autism was first recognized, males with autism have disproportionately skewed research. Females with autism have thus been relatively overlooked, and have generally been assumed to have the same underlying neurobiology as males with autism. Growing evidence, however, suggests that this is an oversimplification that risks obscuring the biological base of autism. This study seeks to answer two questions about how autism is modulated by biological sex at the level of the brain: (i) is the neuroanatomy of autism different in males and females? and (ii) does the neuroanatomy of autism fit predictions from the ‘extreme male brain’ theory of autism, in males and/or in females? Neuroanatomical features derived from voxel-based morphometry were compared in a sample of equal-sized high-functioning male and female adults with and without autism (n = 120, n = 30/group). The first question was investigated using a 2 × 2 factorial design, and by spatial overlap analyses of the neuroanatomy of autism in males and females. The second question was tested through spatial overlap analyses of specific patterns predicted by the extreme male brain theory. We found that the neuroanatomy of autism differed between adult males and females, evidenced by minimal spatial overlap (not different from that occurred under random condition) in both grey and white matter, and substantially large white matter regions showing significant sex × diagnosis interactions in the 2 × 2 factorial design. These suggest that autism manifests differently by biological sex. Furthermore, atypical brain areas in females with autism substantially and non-randomly (P < 0.001) overlapped with areas that were sexually dimorphic in neurotypical controls, in both grey and white matter, suggesting neural ‘masculinization’. This was not seen in males with autism. How differences in neuroanatomy relate to the similarities in cognition between males and females with autism remains to be understood. Future research should stratify by biological sex to reduce heterogeneity and to provide greater insight into the neurobiology of autism.