Inhibition in children with attention-deficit/hyperactivity disorder: a psychophysiological study of the stop task.
BACKGROUND
The purpose of the study was to investigate and identify abnormal brain activity, as revealed by event-related potentials (ERPs) concurring with deficient inhibitory control in children with attention-deficit/hyperactivity disorder (ADHD).


METHODS
Performance and ERPs from 16 children with ADHD and 16 control subjects were compared in the stop-signal paradigm.


RESULTS
The ADHD children showed a lower inhibition percentage and their (estimated) response time to the stop signal was disproportionally longer compared to the slowing of reaction times to primary-task stimuli. In normal control subjects, fronto-central positivity (100-400 msec) after the onset of the stop-signal was larger in case of successful inhibition, relative to failed inhibition; this was less so in ADHD children. A late positive wave (500-700 msec), maximal at Oz on failed inhibition trials, and possibly related to error-detection, was smaller in ADHD children.


CONCLUSIONS
These results point to abnormalities in brain processes involved in motor inhibition and error-detection in ADHD children.
Overtoom
Carin C E
CC
Faculty of Pharmacy, Department of Psychopharmacology, Rudolf Magnus Institute for Neurosciences, Utrecht University, P.O. Box 80082, 3508 TB Utrecht, The Netherlands.
Kenemans
J Leon
JL
Verbaten
Marinus N
MN
Kemner
Chantal
C
van der Molen
Maurits W
MW
van Engeland
Herman
H
Buitelaar
Jan K
JK
Koelega
Harry S
HS
D001289:Attention Deficit Disorder with Hyperactivity / Q000175:diagnosis / Q000503:physiopathology* / Q000523:psychology*; D016022:Case-Control Studies; D002648:Child; D004569:Electroencephalography; D005071:Evoked Potentials; D005260:Female; D006801:Humans; D007266:Inhibition, Psychological; D008297:Male; D011930:Reaction Time; D013647:Task Performance and Analysis