Difficulties of children with symptoms of attention-deficit/hyperactivity disorder in processing temporal information...

It has been hypothesized that children with attention-deficit/hyperactivity disorder (ADHD) present difficulties in processing time durations. However, so far evidence on this difficulty and its related mechanisms has been unclear and collected only with rating scales or laboratory experimental tasks. The current study examined whether this difficulty can be seen in children carrying out everyday actions (e.g., telephone calls, cooking activities) and to what extent it is influenced by working memory (WM) abilities. In total, 182 children aged 7 to 10 years were included in the study: 91 children with ADHD symptoms and 91 typically developing (TD) children matched for gender and other characteristics. We administered sequence reordering, time reproduction, and duration comparison tasks, and as stimuli we used six movies lasting 10 to 60 s showing three women completing six different actions. We also collected measures of verbal and visuospatial WM tests (digit span and Corsi task). Children with ADHD symptoms tended to underestimate the long durations and were less accurate than TD children in remembering the exact order of events and in comparing the duration of two different events. These difficulties appeared to be related to WM abilities.