The Association Between Theory of Mind, Executive Function and the Symptoms of Autism Spectrum Disorder

Background:

Many dominant theories of autism spectrum disorder (ASD) assert that atypical cognitive processes contribute to the expression of observed autistic symptoms. In particular, it is proposed that theory of mind (ToM) impairments relate to the expression of social and communication difficulties, and that poor executive functions associate with the presence of restricted and repetitive behaviours (RRBs). However, experimental evidence is mixed and comprehensive investigation has been limited by small and unrepresentative sample sizes and the absence of wide-ranging task batteries. Further, most previous research has focussed on a cognitive domain in isolation, meaning broader conclusions about the pattern of cognition-behaviour associations cannot be drawn.

Objectives:

We used structural equation modelling (SEM) as a parsimonious and statistically robust way of exploring the associations between ToM and executive function and parent-reported measures of social communication and RRBs.

Methods:

Participants were 100 adolescents (mean age = 15 years 6 months; SD = 6 months) with ASD from the Special Needs and Autism Project (SNAP). The mean full-scale IQ was 84 (SD = 18). Four tasks were used to measure ToM (False belief, Strange stories, Frith-Happé animations, Reading the Mind in the Eyes) and six tasks were used to measure executive functions (Opposite worlds, Card sort, Category fluency, Design fluency, Digit span, Planning drawing). Symptoms of ASD were obtained via parent-report, with the Social Responsiveness Scale (Constantino & Gruber, 2005) used to measure social communication behaviours and the Repetitive Behavior Scale-Revised (Bodfish et al., 2000) used to measure RRBs. SEM enabled different theoretical models of the interrelationships between the multiple measures to be tested and compared.

Results:

Our final model had acceptable model fit (CFI = .89; RMSEA = .05). ToM ability was associated with both social communication symptoms (standardized coefficient = -.41) and RRBs (standardized coefficient = -.42). In contrast, EF was a correlate of ToM but had no direct association with parent-reported symptom expression.

Conclusions:

Our data suggest ToM ability, but not EF, is related to autistic symptom expression in adolescents with ASD. This suggests that the previously held theoretical position that ToM is not relevant to RRBs needs reconsidering.