Event‐ and Time‐Based Prospective Memory and Time Perception in Autistic Adults With and Without Intellectual Disabilities

The aim of this study was to examine time perception (i.e., the sense of the duration, order and passage of time) and event- and time-based prospective memory (PM; i.e., the ability to recall an intention to perform an action in the future) in adults across the wider autism spectrum including those with intellectual disabilities. Sixty-four adults, aged 18-65 years, took part in the study (32 autistic, 32 neurotypical controls). Participants were tested using computerized event- and time-based PM tasks and two different time perception tasks (naturalistic vs. comprehensive consisting of time estimation, time production and time reproduction). Results showed no differences between the groups in both PM tasks after controlling for verbal abilities. Moreover, both groups displayed comparable performance in event- versus time-based PM tasks. Autistic participants showed difficulties in time perception in comparison to neurotypical controls in the naturalistic, but not in the comprehensive time perception task. In both groups better performance in time perception was linked to better event- and time-based PM performance. Given the high relevance of PM in everyday life, further research is needed to support autistic individuals in their day-to-day lives. This is one of the first studies investigating PM in autistic adults, including those with intellectual disabilities, a part of the spectrum that is often overlooked.