Parallel Cognitive Aging in Autism Spectrum Conditions (ASC): A Replication Study

Abstract

Findings on age-related effects on cognition in autism spectrum conditions (ASC) in adulthood are ambiguous across studies. As these studies substantially differ in their methodology, replication studies are needed. In this replication study we used frequentist and Bayesian analyses to investigate the hypothesis that in autistic adults compared to non-autistic adults we see mostly parallel, but also protective age-related cognitive effects. Participants were 88 autistic adults, and 88 non-autistic matched comparisons (age range: 30-89 years). Cognitive measures were administered on the following six domains: verbal memory, visual memory, working memory, Theory of Mind (ToM), verbal fluency, and processing speed, and self-reported cognitive failures. We observed that non-autistic adults outperformed autistic adults on ToM, verbal fluency, and verbal memory, but only the first two were confirmed with Bayesian replication analyses. Also, more cognitive failures were reported by autistic adults. No interactions between group and age were observed, suggesting a parallel age-related effect on all cognitive domains. In sum, we replicated earlier observed difficulties in ToM and verbal fluency which seem to persist at older age. Also, we replicate the previously reported parallel age-related cognitive patterns, but found no evidence for protective age-related patterns.