<b>Neural Correlates of Working Memory Subprocesses in Children with and without ADHD</b>

<p dir="ltr">The current study utilized a well-characterized sample of school-aged children with and without ADHD to examine differences in behavioral working memory performance and to characterize differences in patterns of neural activity associated with different subprocesses in working memory. Behavioral analyses revealed children with ADHD demonstrated worse task accuracy and more variable RT compared to typically developing (TD) children. Differences in accuracy were pronounced on set size five trials, a pattern which aligns with controlled attention models of working memory rather than attentional lapse models, the latter of which have often been used as the framework via which poor working memory performance in ADHD is understood. The ADHD group also demonstrated consistently more variable RT than the TD group, a pattern which was also observed across capacity groups even when task accuracy was high. These results suggest a large degree of heterogeneity within both the ADHD and TD groups and indicate that a defining characteristic of the ADHD group is higher RT variability rather than low task accuracy. In contrast to these behavioral results, no differences in neural activity based on diagnosis were identified, and most capacity groups did not significantly differ from each other in patterns of neural activity as well. Multiple reasons are proposed, including the use of cluster-based permutation to investigate between-group differences and collapsing across factors in neural analyses, such as not examining load or block of task. The two significant clusters identified when comparing the ADHD Normative Capacity group and TD group may suggest different ways that successful working memory performance is achieved, but much further examination is required to support that interpretation.</p>