EEG markers of mind wandering as predictors of sustained attention in pediatric ADHD.

Mind wandering (MW) refers to a shift from task-related, stimulus-driven thoughts to internally generated thoughts. While commonly experienced, particularly among individuals with attention deficit/hyperactivity disorder (ADHD), it remains understudied in children, especially through objective measures such as neural markers. This study aimed, first, to examine differences in neural activation and functional connectivity related to MW between typically developing children and those diagnosed with ADHD. Second, it explored how these neural markers relate to sustained attention in children with ADHD, with the goal of identifying objective indicators for diagnosis. Electroencephalography (EEG) was used to assess current source density and lagged functional connectivity across 13 brain regions associated with MW. Participants completed the Integrated Visual and Auditory Continuous Performance Test (IVA), which measures auditory and visual sustained attention. Children with ADHD showed distinct patterns of neural activation and connectivity, including increased delta and decreased beta connectivity. These changes were accompanied by increased activity in the default mode network (DMN) and impaired regulation by the executive control network (ECN). In addition to the DMN (commonly linked to MW), several non-DMN regions and their connectivity were also associated with various aspects of sustained attention, including focus, vigilance, comprehension, and persistence. These findings highlight the contribution of MW to attentional deficits in ADHD and underscore its potential as a measurable and clinically meaningful feature of ADHD psychopathology, with important implications for both diagnosis and intervention.