Coarser event segmentation and impaired temporal order memory in subclinical ADHD.

We segment a naturalistic, narrative stimulus based on our perception of contextual boundaries. People differ in how they perceive event boundaries, affecting their segmentation and subsequent recall of the temporal structure of the events. Understanding individual difference factors that affect boundary processing will provide further insight in how individuals segment and memorize a naturalistic stimulus. Attention deficit/hyperactivity disorder (ADHD) is a condition that is characterized by altered or impaired temporal attentional allocation. It would follow that participants with a high ADHD predisposition are more likely to miss boundaries and thereby segment a narrative stimulus differently than participants with low ADHD scores. However, it is not known if temporal memory varies with ADHD scores. We report an online study (N = 71) in which we tested boundary reporting and temporal order memory performance of a 22-minute sitcom episode in a sample of healthy volunteers that individually varied in self-reported ADHD scores. Results showed a negative correlation between self-reported ADHD scores and number of reported event boundaries, i.e., participants with higher ADHD scores reported fewer boundaries. Further, participants with higher ADHD scores performed more poorly than lower scoring participants for the temporal order of scene frames crossing a boundary, but not for frames presented in the same scene. These findings can be explained by models of impaired dynamic attentional allocation in ADHD. We discuss our findings in light of current literature and suggest that segmentation of naturalistic stimuli is a potentially powerful way of studying cognition and memory in ADHD.