(Visit: www.uctv.tv/) Cognitive and behavioral consistent inconsistency has come to be a hallmark of attention-deficit/hyperactivity disorder (ADHD). These fluctuations in task performance can be distressing as it is a challenge to understand why persons with ADHD can sometimes present with good attentional focus, yet other times, impaired attention. Typically, researchers tap into these inconsistencies by measuring the degree of variability in response times on a behavioral task. Neuroimaging research is examining patterns of brain activity and connectivity that may underlie these inconsistencies in behavior in ADHD. The increased intra-individual variability in response times in ADHD seems to reflect rhythmicity that is coincident with spontaneous fluctuations in large-scale neural networks. Converging, albeit incomplete, lines of evidence support the overarching hypothesis that dysregulation among such large-scale networks underlies increased variability in ADHD. Series: "MIND Institute Lecture Series on Neurodevelopmental Disorders" [Health and Medicine] [Show ID: 24423]