An Electrocortical Measure Associated with Metarepresentation Mediates the Relationship between Autism Symptoms and Theory of Mind.

Impairments in theory of mind (ToM) - long considered common among individuals with autism spectrum disorder (ASD) - are in fact highly heterogeneous across this population. While such heterogeneity should be reflected in differential recruitment of neural mechanisms during ToM reasoning, no research has yet uncovered a mechanism that explains these individual differences. In this study, 78 (48 ASD) adolescents viewed ToM vignettes and made mental state inferences about characters' behavior while participant electrophysiology was concurrently recorded. Two candidate event-related potentials (ERPs) - the Late Positive Complex (LPC) and the Late Slow Wave (LSW) - were successfully elicited. LPC scores correlated positively with ToM accuracy and negatively with ASD symptom severity. Notably, the LPC partially mediated the relationship between ASD symptoms and ToM accuracy, suggesting this ERP component, thought to represent cognitive metarepresentation, may help explain differences in ToM performance in some individuals with ASD.