Description
Autism spectrum disorder (ASD) is a neurodevelopmental disorder with hallmarks of heterogeneity in etiology and clinical presentation, including findings of increased interindividual variability, or ‘idiosyncrasy’. Studies of intrinsic functional connectivity (FC) and task-induced FC in ASD have produced inconsistent findings with respect to the type and extent of overconnectivity and underconnectivity. As FC patterns have been found to change across different cognitive demands, a relatively novel and more comprehensive approach to investigate network architecture in ASD is to examine the change in FC patterns between rest and task fMRI, referred to as reconfiguration. Examination of FC reconfiguration is, therefore, highly suitable to investigate inefficient network connectivity that may underlie impaired behavioral functioning in clinical disorders. We used functional magnetic resonance imaging (fMRI) to examine FC reconfiguration between rest and task, with additional focus on interindividual variability. Thirty adolescents with ASD and a matched group of typically developing (TD) controls (n=23) completed a lexical decision task that involved distinguishing words of different semantic categories during fMRI. FC and reconfiguration were calculated for regions of interest (ROIs) that showed task-related activation. The ASD group showed overall greater reconfiguration and increased interindividual variability compared to TD. An ASD subgroup with typical-performance accuracy (i.e., at the level of TD participants) showed reduced similarity and typicality of FC during the task. In this ASD subgroup, greater FC reconfiguration was associated with increased language skills. These findings suggest that intrinsic functional networks in ASD may be overall less efficiently organized and require greater reconfiguration during lexicosemantic processing, and that high levels of performance in a lexical decision task may be achieved through atypical or idiosyncratic mechanisms in some individuals with autism.
