Journal of the International Neuropsychological Society

Research Articles

Examining predictors of reaction times in children with ADHD and normal controls

JEFFERY N. EPSTEINa1 c1, MICHELLE E. HWANGa2, TANYA ANTONINIa2, JOSHUA M. LANGBERGa1, MEKIBIB ALTAYEa1 and L. EUGENE ARNOLDa3

a1 Department of Pediatrics, Cincinnati Children’s Hospital Medical Center, Cincinnati, Ohio

a2 Department of Psychology, University of Cincinnati, Cincinnati, Ohio

a3 Department of Psychiatry, Ohio State University, Columbus, Ohio

Abstract

A microanalysis of task events in a common go/no-go task was completed to examine how task events impact individual reaction times. Predictors of long reaction times were analyzed to better understand increased intra-individual variability (IIV) among children with ADHD compared with normal controls. Sixty-five children with ADHD and 65 normal controls matched on gender, ethnicity, and age completed a go/no-go task. Children across both groups were slower before and after omission errors than all other trials. They were also slower on the trial before successfully inhibiting their response to no-go trials. Children with ADHD exhibited a pronounced slowing on trials prior to omission errors and trials prior to successful inhibitions compared with the normal control group. Pre-error slowing in children with ADHD may represent the beginning stages of attentional disengagement that subsequently results in the absence of responding (i.e., errors of omission or successful inhibition). While these event-related increases in reaction time explain some of the increased IIV observed in children with ADHD, the removal of these trials did not remove the pronounced between-group differences in IIV, suggesting that additional unmeasured processes are contributing to IIV in children with ADHD. (JINS, 2010, 16, 138–147.)

(Received July 14 2009)

(Reviewed September 22 2009)

(Accepted September 24 2009)

Correspondence:

c1 Correspondence and reprint requests to: Jeffery N. Epstein, Cincinnati Children’s Hospital Medical Center, Division of Behavioral Medicine and Clinical Psychology, 3333 Burnet Avenue, MLC 10006, Cincinnati, Ohio 45229-3039. E-mail: jeff.epstein@cchmc.org