Effects of mind-wandering on cognitive and neural processes: Identifying specific impairments in adults with attention-deficit/hyperactivity disorder.

Attention-deficit/hyperactivity disorder (ADHD) is a common neurodevelopmental disorder characterized by symptoms of inattention and/or impulsivity/hyperactivity. Although not a core symptom, excessive mind-wandering (MW) is commonly associated with the disorder and may contribute to symptoms as well as performance deficits observed in these patients. The main aim of the present study is to better characterize MW and its impact on performance measures as well as on neural activity in adults with ADHD. Twenty-eight medication-naïve ADHD patients and 28 healthy controls-matched on sex, age, and level of education-completed a prolonged Go/No-Go sustained attention task including thought-probes to detect episodes of MW. Analysis of EEG data focused on P100, P3b, and CRN event-related potentials reflecting early visual, attention allocation, and performance monitoring processes, respectively. MW, particularly spontaneous MW, was more frequent in patients and linked to a more severe ADHD symptomatology. A differentiated negative impact of MW on performance was noted in both groups: variability of reaction times in patients and accuracy in controls were affected. While the same perceptual (P100) and attentional (P3b) impairments were evidenced in both groups during MW, the impairment of the performance monitoring (CRN) process was exclusively highlighted in ADHD patients (as revealed by a significant state × group interaction). Taken together, these results extend the understanding of the cognitive and neural processes associated with increased MW in patients and suggest performance monitoring as a potential key mechanism underlying specific MW-related impairments in ADHD.