The Neural Correlates of Response Inhibition With and Without Conflict in ADHD: An Activation Likelihood Estimation...

Attention-deficit/hyperactivity disorder (ADHD) is a prevalent neurodevelopmental disorder marked-among other features-by impairments in response inhibition, a complex cognitive process assessable through tasks that either involve conflict suppression (C tasks) or do not (no-C tasks). Previous research has linked impaired response inhibition in ADHD primarily to structural and functional abnormalities in fronto-striatal and fronto-parietal networks. However, it remains unclear how these neural circuits differentially support performance on C and no-C tasks in individuals with ADHD. To address this question, we conducted a meta-analysis using the activation likelihood estimation (ALE) method. We included the available functional magnetic resonance imaging (fMRI) studies (N = 30) examining children and adolescents with ADHD during C and no-C response inhibition tasks. Across both task types, ADHD participants consistently engaged a fronto-striatal circuit comprising the inferior frontal gyrus (IFG), anterior cingulate cortex (ACC), and caudate nuclei. When the analysis was restricted on C tasks, activation was primarily observed in the right IFG. In contrast, no-C tasks elicited activation in the left caudate nucleus, with the additional involvement of the right caudate and ACC during successful response inhibition (i.e., correct performance). These findings reveal a functional dissociation within frontal-striatal circuits during response inhibition in children and adolescents with ADHD, with the IFG specifically supporting conflict suppression, and the ACC and caudate nuclei contributing more to successful inhibition in tasks without conflict.