Maturation of auditory neural processes in autism spectrum disorder – A longitudinal MEG study

Background: Individuals with autism spectrum disorder (ASD) show atypical brain activity, perhaps due to delayed maturation. Previous studies examining the maturation of auditory electrophysiological activity have been limited due to their use of cross-sectional designs. The present study took a first step in examining magnetoencephalography (MEG) evidence of abnormal auditory response maturation in ASD via the use of a longitudinal design.

Methods: Initially recruited for a previous study, 27 children with ASD and nine typically developing (TD) children, aged 6- to 11-years-old, were re-recruited two to five years later. At both timepoints, MEG data were obtained while participants passively listened to sinusoidal pure-tones. Bilateral primary/secondary auditory cortex time domain (100 ms evoked response latency (M100)) and spectrotemporal measures (gamma-band power and inter-trial coherence (ITC)) were examined. MEG measures were also qualitatively examined for five children who exhibited “optimal outcome”, participants who were initially on spectrum, but no longer met diagnostic criteria at follow-up.

Results: M100 latencies were delayed in ASD versus TD at the initial exam (~ 19 ms) and at follow-up (~ 18 ms). At both exams, M100 latencies were associated with clinical ASD severity. In addition, gamma-band evoked power and ITC were reduced in ASD versus TD. M100 latency and gamma-band maturation rates did not differ between ASD and TD. Of note, the cohort of five children that demonstrated “optimal outcome” additionally exhibited M100 latency and gamma-band activity mean values in-between TD and ASD at both timepoints. Though justifying only qualitative interpretation, these “optimal outcome” related data are presented here to motivate future studies.

Conclusions: Children with ASD showed perturbed auditory cortex neural activity, as evidenced by M100 latency delays as well as reduced transient gamma-band activity. Despite evidence for maturation of these responses in ASD, the neural abnormalities in ASD persisted across time. Of note, data from the five children whom demonstrated “optimal outcome” qualitatively suggest that such clinical improvements may be associated with auditory brain responses intermediate between TD and ASD. These “optimal outcome” related results are not statistically significant though, likely due to the low sample size of this cohort, and to be expected as a result of the relatively low proportion of “optimal outcome” in the ASD population. Thus, further investigations with larger cohorts are needed to determine if the above auditory response phenotypes have prognostic utility, predictive of clinical outcome.

Keywords: ASD; Gamma; M100; MEG; Maturation.

he phenotypic complexity of Autism Spectrum Disorder motivates the application of
modern computational methods to large collections of observational data, both for improved clinical diagnosis and for better scientific understanding. We have begun to create a
corpus of annotated language samples relevant to this research, and we plan to join with
other researchers in pooling and publishing
such resources on a large scale. The goal of
this paper is to present some initial explorations to illustrate the opportunities that such
datasets will afford

Two populations have been found to exhibit delays in theory of mind (ToM): deaf children of hearing parents and children with autism spectrum disorder (ASD). Deaf children exposed to sign from birth by their deaf parents, however, show no such delay, suggesting that early language exposure is key to ToM development. Sign languages also present frequent opportunities with visual perspective-taking (VPT), leading to the question of whether sign exposure could benefit children with ASD. We present the first study of children with ASD exposed to sign from birth by their deaf parents. Seventeen native-signing children with a confirmed ASD diagnosis and a chronological- and mental age-matched control group of 18 typically developing (TD) native-signing deaf children were tested on American Sign Language (ASL) comprehension, two minimally verbal social cognition tasks (ToM and VPT), and one spatial cognition task (mental rotation). The TD children outperformed the children with ASD on ASL comprehension (p < 0.0001), ToM (p = 0.02), and VPT (p < 0.01), but not mental rotation (p = 0.12). Language strongly correlated with ToM (p < 0.01) and VPT (p < 0.001), but not mental rotation (p = ns). Native exposure to sign is thus insufficient to overcome the language and social impairments implicated in ASD. Contrary to the hypothesis that sign could provide a scaffold for ToM skills, we find that signing children with ASD are unable to access language so as to gain any potential benefit sign might confer. Our results support a strong link between the development of social cognition and language, regardless of modality, for TD and ASD children. Autism Res 2016, 9: 1304-1315. © 2016 International Society for Autism Research, Wiley Periodicals, Inc.

Keywords: cognitive neuroscience; developmental psychology; social cognition; theory of mind.

Background: Autism spectrum disorder (ASD) encompasses a complex manifestation of symptoms that include deficits in social interaction and repetitive or stereotyped interests and behaviors. In keeping with the increasing recognition of the dimensional characteristics of ASD symptoms and the categorical nature of a diagnosis, we sought to delineate the neural mechanisms of ASD symptoms based on the functional connectivity of four known neural networks (i.e., default mode network, dorsal attention network, salience network, and executive control network).

Methods: We leveraged an open data resource (Autism Brain Imaging Data Exchange) providing resting-state functional magnetic resonance imaging data sets from 90 boys with ASD and 95 typically developing boys. This data set also included the Social Responsiveness Scale as a dimensional measure of ASD traits. Seed-based functional connectivity was paired with linear regression to identify functional connectivity abnormalities associated with categorical effects of ASD diagnosis, dimensional effects of ASD-like behaviors, and their interaction.

Results: Our results revealed the existence of dimensional mechanisms of ASD uniquely affecting each network based on the presence of connectivity-behavioral relationships; these were independent of diagnostic category. However, we also found evidence of categorical differences (i.e., diagnostic group differences) in connectivity strength for each network as well as categorical differences in connectivity-behavioral relationships (i.e., diagnosis-by-behavior interactions), supporting the coexistence of categorical mechanisms of ASD.

Conclusions: Our findings support a hybrid model for ASD characterization that includes a combination of categorical and dimensional brain mechanisms and provide a novel understanding of the neural underpinnings of ASD.

Keywords: Autism spectrum disorder; Default mode network; Dimensional measures; Functional connectivity; Resting-state fMRI; Social cognition.

2016Emory UniversityTom CariveauLawrence Scahill

Little is known about the social behavior of children with and without autism spectrum disorder during recess. This study documented the naturally occurring recess engagement and peer interaction behaviors of children with and without autism spectrum disorder in inclusive school settings. Participants included 51 children with autism spectrum disorder and 51 classmates without autism spectrum disorder who served as peer models matched on gender, classroom, grade, age, and ethnicity. Using a timed-interval behavior-coding system, children with autism spectrum disorder spent approximately 30% of their recess time engaged in solitary activities, whereas their classmates only spent approximately 9% of recess unengaged. In addition, children with autism spectrum disorder spent about 40% of the recess period jointly engaged with peers in a reciprocal activity, conversation, or game as compared to 70% for matched classmates. These findings provide a context for which to interpret intervention outcomes and gains for children with autism spectrum disorder in inclusive settings.

Keywords: autism spectrum disorder; peers; playground engagement; social communication.

Although children with autism spectrum disorder are frequently included in mainstream classrooms, it is not known how their social networks change compared to typically developing children and whether the factors predictive of this change may be unique. This study identified and compared predictors of social connectivity of children with and without autism spectrum disorder using a social network analysis. Participants included 182 children with autism spectrum disorder and 152 children without autism spectrum disorder, aged 5-12 years in 152 general education K-5 classrooms. General linear models were used to compare how age, classroom size, gender, baseline connectivity, diagnosis, and intelligence quotient predicted changes in social connectivity (closeness). Gender and classroom size had a unique interaction in predicting final social connectivity and the change in connectivity for children with autism spectrum disorder; boys who were placed in larger classrooms showed increased social network fragmentation. This increased fragmentation for boys when placed in larger classrooms was not seen in typically developing boys. These results have implications regarding placement, intervention objectives, and ongoing school support that aimed to increase the social success of children with autism spectrum disorder in public schools.

Children with ASD show high frequency of restricted and repetitive behaviors (RRBs); however, higher-order RRBs, such as restricted interests, have remained largely resistant to treatment. This study evaluated change in severity of RRBs following a 16-weeks open trial of Pivotal Response Treatment (PRT). Participants included 15 children with ASD ages 4-7 years. RRBs, as measured by the repetitive behavioral scales-revised (RBS-R) and aberrant behaviors checklist, decreased significantly after treatment. These reductions remained significant after controlling for change in social communication skills. PRT shows promise in reducing RRBs; although PRT explicitly addresses pivotal social communication skills, there is a secondary and less direct effect on RRBs.

Keywords: Behavior therapy; Pivotal Response Treatment (PRT); Repetitive Behavior Scale-Revised (RBS-R); Restricted and repetitive behaviors.

Behavioral interventions for autism have gained prominence in recent years; however, the neural-systems-level targets of these interventions remain poorly understood. We use a novel Bayesian framework to extract network-based differences before and after a 16-week pivotal response treatment (PRT) regimen. Our results suggest that the functional changes induced by PRT localize to the posterior cingulate and are marked by a shift in connectivity from the orbitofrontal cortex to the occipital-temporal cortex. Our results illuminate a potential PRT-induced learning mechanism, whereby the neural circuits involved during social perception shift from sensory and attentional systems to higher-level object and face processing areas.

Many consensus guidelines encourage parents and teachers to openly communicate about their concerns regarding their children. These guidelines attest to the importance of achieving consensus about what issues are most critical and how to address them. The purpose of this study was to examine whether parents and teachers (1) agree about their concerns for their children with autism and (2) when given the opportunity, whether they discussed these concerns. Participants were 39 parent-teacher dyads of children with autism in kindergarten-through-fifth grade autism support classrooms. Each parent and teacher was interviewed separately about their concerns and then observed together in a discussion about the child. Parents and teachers generally agreed about their primary and secondary concerns. When given an opportunity to communicate their concerns, 49% of the parent-teacher dyads discussed problems that neither reported as their primary concern, and 31% discussed problems that neither reported as their primary or secondary concern. These findings suggest that interventions should target parent-teacher communication, rather than agreement, to facilitate home-school collaboration.

Keywords: autism; autism spectrum disorders; family–school partnerships; parent–teacher communication.

Effective parent-teacher communication involves problem-solving concerns about students. Few studies have examined problem solving interactions between parents and teachers of children with autism spectrum disorder (ASD), with a particular focus on identifying communication barriers and strategies for improving them. This study examined the problem-solving behaviors of parents and teachers of children with ASD. Participants included 18 teachers and 39 parents of children with ASD. Parent-teacher dyads were prompted to discuss and provide a solution for a problem that a student experienced at home and at school. Parents and teachers also reported on their problem-solving behaviors. Results showed that parents and teachers displayed limited use of the core elements of problem-solving. Teachers displayed more problem-solving behaviors than parents. Both groups reported engaging in more problem-solving behaviors than they were observed to display during their discussions. Our findings suggest that teacher and parent training programs should include collaborative approaches to problem-solving.

Keywords: autism; autism spectrum disorder; parent-teacher communication; problem-solving.