Fluctuations of Attention During Self-paced Naturalistic Goal-Directed Behavior in Attention-Deficit/Hyperactivity Disorder.

Objective: Temporal fluctuations of attention detected with strictly controlled neuropsychological tests is an important objective behavioral marker for attention-deficit/hyperactivity disorder (ADHD). This study examined whether intraindividual variability in response latencies is also detectable in more realistic open-ended virtual contexts where the participants can freely interact with the surroundings when performing instructed everyday tasks from memory. Method: Three ex-Gaussian parameters, μ, σ, and τ, were derived from response latencies in 2 tasks obtained from 2 datasets comprising 9- to 13-year-old children (72 with ADHD and 71 typically developing controls). In the Executive Performance in Everyday LIving (EPELI) task, participants performed instructed household chores in a virtual apartment. In the other task, a continuous performance test (CPT), was used to examine whether previous findings were replicated in this sample. Results: Children with ADHD had shorter response latencies than controls in the EPELI task, while group differences in τ reflecting occasional sluggish responses depended on whether the trials were task-relevant (smaller τ in children with ADHD) or task-irrelevant (larger τ in children with ADHD). CPT results replicated previous observations of longer response latencies and larger τ in children with ADHD compared with control children. Intraindividual variability in the naturalistic EPELI task, however, explained more of the symptom variability than the CPT. Conclusion: This study demonstrates that task context and stimulus relevance considerably influence how intraindividual variability in attention is manifested in children with ADHD. Virtual reality tasks provide a promising avenue for ecologically relevant quantification of this common cognitive deficit in neuropsychiatric disorders.