Reaction Time Distribution Analysis of Neuropsychological Performance in an ADHD Sample

Abstract

Differences in reaction time (RT) variability have been documented between children with and without Attention Deficit Hyperactivity Disorder (ADHD). Most previous research has utilized estimates of normal distributions to examine variability. Using a nontraditional approach, the present study evaluated RT distributions on the Conners' Continuous Performance Test in children and adolescents from the Multimodal Treatment Study of ADHD sample compared to a matched sample of normal controls (n = 65 pairs). The ex-Gaussian curve was used to model RT and RT variability. Children with ADHD demonstrated faster RT associated with the normal portion of the curve and a greater proportion of abnormally slow responses associated with the exponential portion of the curve. These results contradict previous interpretation that children with ADHD have slower than normal responding and demonstrate why slower RT is found when estimates of variability assume normal Gaussian distributions. Further, results of this study suggest that the greater number of abnormally long RTs of children with ADHD reflect attentional lapses on some but not all trials.

fMRI: blood oxygen level–dependent activation during a working memory–selective attention task in children born extremely preterm

“…4,5,7). Recent studies suggest that lack of attention in only Articles a few responses may be the cause of the overall prolonged RTs documented in children with attention-deficit hyperactivity disorder (31,32). This was a relevant possibility also for our preterm children, and a reason to add RT to our study design.…”

Understanding the Effects of Stimulant Medications on Cognition in Individuals with Attention-Deficit Hyperactivity Disorder: A Decade of Progress

“…The ADHD-control differences revealed by this 'Ex-Gaussian' analysis may depend on the task used. Hervey et al (2006) evaluated a group of stimulant-naïve ADHD children in the MTA follow-up study (n ¼ 65) and matched group classmates without ADHD (n ¼ 65) using a Go-NoGo task (the Conners' CPT). On the basis of standard analyses, the ADHD group had a longer MRT and greater SD and skewness.…”

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