Patterns of altered neural synchrony in the default mode network in autism spectrum disorder revealed with magnetoencephalography (MEG): Relationship to clinical symptomatology

Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/142922/1/aur1908.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/142922/2/aur1908_am.pd

Atypical processing of gaze cues and faces explains comorbidity between autism spectrum disorder (ASD) and attention deficit/hyperactivity disorder (ADHD)

This study investigated the neurobiological basis of comorbidity between autism spectrum disorder (ASD) and attention deficit/hyperactivity disorder (ADHD). We compared children with ASD, ADHD or ADHD+ASD and typically developing controls (CTRL) on behavioural and electrophysiological correlates of gaze cue and face processing. We measured effects of ASD, ADHD and their interaction on the EDAN, an ERP marker of orienting visual attention towards a spatially cued location and the N170, a right-hemisphere lateralised ERP linked to face processing. We identified atypical gaze cue and face processing in children with ASD and ADHD+ASD compared with the ADHD and CTRL groups. The findings indicate a neurobiological basis for the presence of comorbid ASD symptoms in ADHD. Further research using larger samples is needed

Predictive processing during a naturalistic statistical learning task in ASD

© 2020 Wagley et al. Children’s sensitivity to regularities within the linguistic stream, such as the likelihood that syllables co-occur, is foundational to speech segmentation and language acquisition. Yet, little is known about the neurocognitive mechanisms underlying speech segmentation in typical development and in neurodevelopmental disorders that impact language acquisition such as autism spectrum disorder (ASD). Here, we investigate the neural signals of statistical learning in 15 human participants (children ages 8–12) with a clinical diagnosis of ASD and 14 age-matched and gender-matched typically developing peers. We tracked the evoked neural responses to syllable sequences in a naturalistic statistical learning corpus using magnetoencephalography (MEG) in the left primary auditory cortex, posterior superior temporal gyrus (pSTG), and inferior frontal gyrus (IFG), across three repetitions of the passage. In typically developing children, we observed a neural index of learning in all three regions of interest (ROIs), measured by the change in evoked response amplitude as a function of syllable surprisal across passage repetitions. As surprisal increased, the amplitude of the neural response increased; this sensitivity emerged after repeated exposure to the corpus. Children with ASD did not show this pattern of learning in all three regions. We discuss two possible hypotheses related to children’s sensitivity to bottom-up sensory deficits and difficulty with top-down incremental processing

Is theory of mind related to social dysfunction and emotional problems in 22q11.2 deletion syndrome (velo-cardio-facial syndrome)?

Social dysfunction is intrinsically involved in severe psychiatric disorders such as depression and psychosis and linked with poor theory of mind. Children with 22q11.2 deletion syndrome (22q11DS, or velo-cardio-facial syndrome) have poor social competence and are also at a particularly high risk of developing mood (40%) and psychotic (up to 30%) disorders in adolescence and young adulthood. However, it is unknown if these problems are associated with theory of mind skills, including underlying social-cognitive and social-perceptual mechanisms. The present cross-sectional study included classic social-cognitive false-belief and mentalising tasks and social-perceptual face processing tasks. The performance of 50 children with 22q11DS was compared with 31 age-matched typically developing sibling controls. Key findings indicated that, while younger children with 22q11DS showed impaired acquisition of social-cognitive skills, older children with 22q11DS were not significantly impaired compared with sibling controls. However, children with 22q11DS were found to have social-perceptual deficits, as demonstrated by difficulties in matching faces on the basis of identity, emotion, facial speech and gaze compared with sibling controls. Furthermore, performance on the tasks was associated with age, language ability and parentally rated social competence and emotional problems. These results are discussed in relation to the importance of a better delineation of social competence in this population

Presurgical localization of language regions and their networks

MEG language-evoked fields (LEFs) are reliably used for detecting the dominant hemisphere of language processing. This laterality measure is based on the accurate localization of Broca’s and Wernicke’s activated areas during language processing. There are several tasks ranging from semantic decision-making, verb generation, and picture naming to auditory word presentation that have been used with success. These tasks can be expressive (where Broca’s activity is strongly activated) or receptive (where Wernicke’s is strongly activated). In the general population, most right-handed individuals are left hemispheric dominant for language. Patients requiring surgical resection will have language mapping performed, so the surgeon can be aware that there may be displacement of either or both Broca’s and Wernicke’s language processing areas near the planned resection site. Since epilepsy may disrupt only Broca’s or only Wernicke’s networks, it is wise to map both expressive and receptive language processing. The use of MEG neuroimaging techniques is needed to reliably predict altered language networks in patients and to provide definitive identification of language eloquent cortices for localization and lateralization necessary for clinical care