Uncovering the Social Deficits in the Autistic Brain. A Source-Based Morphometric Study

Autism is a neurodevelopmental disorder that mainly affects social interaction and communication. Evidence from behavioral and functional MRI studies supports the hypothesis that dysfunctional mechanisms involving social brain structures play a major role in autistic symptomatology. However, the investigation of anatomical abnormalities in the brain of people with autism has led to inconsistent results. We investigated whether specific brain regions, known to display functional abnormalities in autism, may exhibit mutual and peculiar patterns of covariance in their gray-matter concentrations. We analyzed structural MRI images of 32 young men affected by autistic disorder (AD) and 50 healthy controls. Controls were matched for sex, age, handedness. IQ scores were also monitored to avoid confounding. A multivariate Source-Based Morphometry (SBM) was applied for the first time on AD and controls to detect maximally independent networks of gray matter. Group comparison revealed a gray-matter source that showed differences in AD compared to controls. This network includes broad temporal regions involved in social cognition and high-level visual processing, but also motor and executive areas of the frontal lobe. Notably, we found that gray matter differences, as reflected by SBM, significantly correlated with social and behavioral deficits displayed by AD individuals and encoded via the Autism Diagnostic Observation Schedule scores. These findings provide support for current hypotheses about the neural basis of atypical social and mental states information processing in autism

Right Temporoparietal Gray Matter Predicts Accuracy of Social Perception in the Autism Spectrum

Individuals with an autism spectrum disorder (ASD) show hallmark deficits in social perception. These difficulties might also reflect fundamental deficits in integrating visual signals. We contrasted predictions of a social perception and a spatial–temporal integration deficit account. Participants with ASD and matched controls performed two tasks: the first required spatiotemporal integration of global motion signals without social meaning, the second required processing of socially relevant local motion. The ASD group only showed differences to controls in social motion evaluation. In addition, gray matter volume in the temporal–parietal junction correlated positively with accuracy in social motion perception in the ASD group. Our findings suggest that social–perceptual difficulties in ASD cannot be reduced to deficits in spatial–temporal integration

A Comparison between Schizophrenia and Autism

Autism spectrum disorder and schizophrenia share a substantial number of etiologic and phenotypic characteristics. Still, no direct comparison of both disorders has been performed to identify differences and commonalities in brain structure. In this voxel based morphometry study, 34 patients with autism spectrum disorder, 21 patients with schizophrenia and 26 typically developed control subjects were included to identify global and regional brain volume alterations. No global gray matter or white matter differences were found between groups. In regional data, patients with autism spectrum disorder compared to typically developed control subjects showed smaller gray matter volume in the amygdala, insula, and anterior medial prefrontal cortex. Compared to patients with schizophrenia, patients with autism spectrum disorder displayed smaller gray matter volume in the left insula. Disorder specific positive correlations were found between mentalizing ability and left amygdala volume in autism spectrum disorder, and hallucinatory behavior and insula volume in schizophrenia. Results suggest the involvement of social brain areas in both disorders. Further studies are needed to replicate these findings and to quantify the amount of distinct and overlapping neural correlates in autism spectrum disorder and schizophrenia

Developing an intricate social brain: functional and structural correlates of socioemotional skills and their association with mental well-being

Socioemotional skills encompass a large set of abilities, which develop from early on and continue to being fine-tuned until late adulthood. The mastery of socioemotional abilities is associated with better social bonds and general psychological well-being in everyday life. Furthermore, it may also play an important role during challenging life circumstances. The fundamentals of mentalizing, the ability of perspective-taking, are acquired in early childhood laying the foundation for the development of more complex social skills across life. The ability to infer mental states aids interpersonal relations and is commonly considered beneficial. However, overly high, or low levels of mentalizing might lead to disturbances in social interactions or elevated stress. The neurobiological foundation for mentalizing has been well studied in adults, however evidence in developmental groups is still lagging behind, despite considerable advances in pediatric neuroimaging over recent years. The main aim of this thesis was to summarize existing knowledge and generate new evidence on the development of the neural correlates for mentalizing. Furthermore, links between the neural correlates of socioemotional processing (i.e., mentalizing or emotion regulation) and psychosocial functioning are investigated. To achieve these goals, we first conducted a meta-analysis synthesizing theory of mind-related neural findings in children and adolescents comparing them to adult findings. Furthermore, we developed and validated a novel cartoon story-based theory of mind functional magnetic resonance imaging task feasible for young children. Finally, the onset of Covid-19 was recognized as a possibly impactful adverse global experience, allowing for the investigation of socioemotional and psychological well-being during challenging life circumstances. Neural correlates of mentalizing and emotion regulation skills were investigated in relation to mental health outcomes during the Covid-19 pandemic. Within this thesis I first present meta-analytic evidence for an early development of the mentalizing network. Large correspondence of child, adolescent, and adult neural findings exist (as reflected by activation in temporoparietal junction, precuneus and middle medial prefrontal cortex across all age groups) but continuous change is observed across age, including more extensive activation pattern with increased age. Secondly, we developed a novel cognitive and affective theory of mind cartoon task (CAToon), which was evaluated behaviorally as well as through fMRI in children and adults. Our findings warrant future use of the task in developmental neuroimaging studies of mentalizing. Third, during stressful life circumstances, here associated with the Covid-19 pandemic, variations in adults’ and children’s mental health are observed. And finally, brain structure (i.e., emotion regulatory areas) and function (i.e., neural activation elicited during mentalizing) measured prior to the pandemic was linked to variables of psychosocial functioning in children and adults (e.g., fears about contamination or caregiving burden, anxiety, or depression). In summary, my thesis I provides novel neuroimaging evidence that describes the development of socioemotional skills across childhood and adulthood and present selected examples of the association of socioemotional processes with mental well-being. In the future, neurodevelopmental studies assessing socioemotional skills and psychosocial functioning could profit from longitudinal approaches and the inclusion of a combination of neurophysiological and behavioral measures from an early age

Valuation of socially relevant facial expressions and gestures: fMRI and clinical investigations

Prochnow D. Valuation of socially relevant facial expressions and gestures: fMRI and clinical investigations. Bielefeld: Universitätsbibliothek Bielefeld; 2013.As people are social beings, they are inclined to infer the emotions and intentions of their counterpart in order to adapt their behavior. This capacity, which is often referred to as forming a cognitive and emotional theory of mind (ToM), can consolidate social relations and also helps protecting people’s well-being. In this process, body language, such as facial expressions and gestures, is an important source of information, in particular, since it develops beyond voluntary control. Based on current research, this dissertation aimed at exploring the brain activation patterns related to different aspects of nonverbal body language used as a source of empathic evaluation such as dynamics, ambiguity, subjective relevance and accessibility to conscious evaluation. Based on reports of a ToM deficit associated with older age, empathic reasoning based on affective states seen in photographs was compared in young and old adults. Taken together, our experiments highlight the role of the inferior frontal cortex, the adjacent anterior insula cortex and the dorsomedial frontal cortex in empathic evaluation based on facial expressions and gestures. Brain areas associated with the putative human mirror neuron system were recruited regardless whether the seen emotional expression was ambiguous due to its dynamics or its low degree of emotional expressiveness, not consciously accessible or of varying degree of social impact. Within correspondence to previous research on emotional contagion, empathy and ToM, this finding highlights the relevance of perception-action-coupling in social life. In addition, parts of the DMFC became activated either with or without an explicit instruction to empathize. The DMFC has been implicated in affective ToM, primarily with a self-referential component. Areas in the DMFC, as well as parts of the hMNS were shown to be recruited in young, as well as in old adults but at different time points. In contrast to the young adults who accurately inferred the origin of an emotional state seen in a face, the old adults’ deficit in efficiently forming a ToM was related to a too early engagement of anterior prefrontal higher order control areas. This was likely to bind cognitive resources due to upregulation of other top-down modulated ToM associated areas at a time point when not all relevant information for efficient reasoning was available. Finally, we consistently found activation within the DLFC supporting the notion that it is not only crucially involved in social decision-making but that there is some degree of functional specialization within this large frontal area. While activation in posterior parts of the DLFC became activated during the preparatory stage of the decision when some but not all decision-relevant information were present, the actual decision was reflected by activation of a more anterior portion of the DLFC being interconnected with premotor, and dorsomedial frontal areas

Language and thought are not the same thing: evidence from neuroimaging and neurological patients

Is thought possible without language? Individuals with global aphasia, who have almost no ability to understand or produce language, provide a powerful opportunity to find out. Surprisingly, despite their near-total loss of language, these individuals are nonetheless able to add and subtract, solve logic problems, think about another person's thoughts, appreciate music, and successfully navigate their environments. Further, neuroimaging studies show that healthy adults strongly engage the brain's language areas when they understand a sentence, but not when they perform other nonlinguistic tasks such as arithmetic, storing information in working memory, inhibiting prepotent responses, or listening to music. Together, these two complementary lines of evidence provide a clear answer: many aspects of thought engage distinct brain regions from, and do not depend on, language