Cognitive deficits in children with Autism Spectrum Disorders (ASD) are well known. Still we question whether cognitive subgroups exist and whether cognition is associated with core autistic behaviours and/or psychopathology.
The aim of this study was to look at cognitive subgroups and examine how cognition may be associated with core autistic behaviours.
31 children diagnosed with an ASD together with 38 neurotypically developed (NTD) children were all tested with a comprehensive 4-hour neuropsychological battery covering the cognitive domains: Theory of Mind (ToM), Executive Functions (EF) and Central Coherence (CC). All children were aged between 8 and 12 years and had IQs between 75 and 145. Core ASD symptoms were assessed with the ADOS and ADI-R, and comorbid symptoms were rated by parents (CBCL) and teachers (TRF).
We found that the ASD and NTD groups differed significantly on the ToM-composite and EF-composite but not on the CC-composite. No correlations between these three composites were found. The ASD cases were divided into (relatively) good and poor performers on each of the 3 cognitive composites and these groups were compared. The poor ToM-group (N=20) showed greater parent-reported anxiety and internalizing behaviour but did not differ from the good ToM-group in terms of their ASD symptoms. The poor EF-group (N=9) displayed more severe verbal and non-verbal communication symptoms on the ADI-R, as well as greater difficulties using non-verbal means to regulate social interactions and more severe stereotyped and repetitive motor mannerisms. Surprisingly, this group also presented with fewer conduct problems according to both teacher and parent ratings.
ToM and EF alterations are characteristic of individuals with ASD and differentiate this population from NTD individuals. However, there also appears to be cognitive heterogeneity within the autism spectrum, with only a proportion of individuals displaying each cognitive abnormality. EF difficulties appear to predict ASD symptoms whilst ToM difficulties predict comorbid symptoms.
See more of: Cognition and Behavior
See more of: Symptoms, Diagnosis & Phenotype