The atypical social brain network in autism: Advances in structural and functional MRI studies

Purpose of review: To review advances in structural and functional MRI studies regarding the neural underpinnings of social atypicalities in autism spectrum disorder (ASD). Recent findings: According to the hypothesis that the social brain network, which includes brain regions, such as the amygdala and superior temporal sulcus, may be atypical in ASD, recent structural MRI studies have identified regional gray matter volume abnormalities in the social brain regions in ASD groups compared with the typically developing groups. Studies evaluating gray matter volume covariance and white matter volume/integrity suggested network-level abnormalities associated with the social brain regions. Recent functional MRI studies assessing resting-state neural activity showed reduced functional connectivity among the social brain regions in individuals with ASD compared with typically developing groups. Similarly, task-based functional MRI studies recently revealed a reduction in regional activity and intraregional functional coupling in the social brain regions during the processing of social stimuli in individuals with ASD. Summary: These structural and functional MRI studies provide supportive evidence for the hypothesis that an atypical social brain network underlies behavioral social problems in ASD

Changes in Electroencephalogram Coherence in Adolescents with Autism Spectrum Disorder after a Social Skills Intervention

Autism spectrum disorder (ASD) is a developmental disorder that affects social communication and behavior. There is a consensus that neurological differences present in individuals with ASD. Further, theories emphasize the mixture of hypo- and hyper-connectivity as a neuropathology in ASD (O’Reilly, Lewis, & Elsabbagh, 2017), however, there is a paucity of studies specifically testing neurological underpinnings as predictors of success on social skills interventions. This study examined functional neural connectivity (electroencephalogram, EEG, coherence) of adolescents with ASD before and after the Program for the Education and Enrichment of Relational Skills (PEERS®) intervention. Two groups were utilized in this randomized controlled trial (RCT): an Experimental ASD Group (EXP ASD; n = 74) and a Waitlist Control ASD Group (WL ASD; n = 74). The study had 2 purposes. Aim 1 was to determine whether changes in EEG coherence differed in adolescents with ASD receiving PEERS® compared to a waitlist control group of ASD adolescents that did not receive the intervention. Results revealed a statistically significant difference between groups in EEG coherence in the occipital left to temporal left pair; indicating an increase of connectivity between the occipital left and temporal left regions after intervention. Aim 2 was to determine if changes in EEG coherence related to changes in behavior, friendships, and social skills via the Social Skills Improvement System (SSIS: Gresham, 2009), Social Responsiveness Scale (SRS: Constantino, 2005), Quality of Socialization Questionnaire-Adolescent (QSQ-A: Laugeson, 2010), and Test of Adolescent Social Skills (TASSK: Laugeson, 2010). Results indicated a positive change in frontal right to parietal right coherence was linked to an increase in SSIS Social Skills scores at post-test. Positive changes in occipital right to temporal right coherence and occipital left to parietal left coherence were linked to an increase in the total number of get-togethers via the QSQ-A. Results of this study have implications for the importance of assessing response to treatment in ASD using neurobehavioral domains

The Environment and Child Development: A Multivariate Approach

The environment that a child grows up in has a profound effect on their child development. For example, key outcomes such as academic ability or behaviour, cognitive ability and the neurobiology of the brain have been found to be associated to a child’s environment. However, the factors that make up a child’s environment are highly complex and yet the majority of research treats SES as a single number. In addition, the environment is related to several aspects of a child’s development, yet there is very little research considering how these multiple levels of development relate to each other and interact. This thesis builds on the current literature by investigating how multiple aspects of a child’s environment combine to create an environmental profile that is associated with positive child development. We endeavour to address three questions: 1) Which environmental factors most strongly relate to a child’s academic ability, behaviour, cognitive ability and neural development? 2) Does the wider environment mediate the relationship between standard measures of SES and child development? 3) How might the environment impact academic and behaviour outcomes? In particular, is this relationship mediated by a child’s cognition or the structural and functional connectivity of their brain? 7-11 year-old children (N=97) and their caregivers took part in this study. Several environmental domains and child behaviour were assessed through caregiver and child questionnaires. Academic and cognitive ability were measured using behavioural assessments. Resting state functional connectivity was measured using a magnetoencephalography (MEG) scan and structural connectivity was measured in an optional MRI scan on a separate visit (N=87). Partial Least Squares (PLS) methods identified significant relationships between the environment and child development. Multiple environmental domains were found to be reliably related to each aspect of child development. Furthermore, the wider environmental domains mediated the association between SES measures and each aspect of child development. Finally, cognition and the structural connectivity of a child’s brain mediated the association between the environment and academic outcomes. This was not found for the behavioural outcomes. This thesis provides key advances towards addressing the considerable methodological challenge presented in the investigation of the complex relationships between a child’s environment and multiple aspects of their development. We believe that this work will complement the available research to date and provide important detail to enable practitioners and policymakers to better support children at risk from disadvantaged environments.Funded by the Medical Research Counci