Inhibitory motor control in children with attention-deficit/hyperactivity disorder: event-related potentials in the stop-signal paradigm.
BACKGROUND
The aim of the study was to investigate the inhibitory control of an ongoing motor response and to identify underlying neural deficiencies, manifested in event-related potentials, that cause poorer inhibitory performance in children with attention-deficit/hyperactivity disorder.


METHODS
A stop-signal paradigm with a primary visual task and auditory stop signal was used to compare performance in 13 children with attention-deficit/hyperactivity disorder and 13 control children, while event-related potentials were recorded simultaneously.


RESULTS
Children with attention-deficit/hyperactivity disorder showed poorer inhibitory performance through a slower inhibitory process. Inhibitory processing of auditory stop signals was marked by a frontal N2 component that was reduced in the attention-deficit/hyperactivity disorder group relative to controls. A central positive component (P3) was associated with the success of inhibiting a response, but there were no group differences in its amplitude or latency.


CONCLUSIONS
Findings support the hypothesis of deficient inhibitory control in children with attention-deficit/hyperactivity disorder. Slower inhibitory processing appears to be due to a specific neural deficiency that manifests in the processing of the stop signal as attenuated negativity in the N2 latency range.
Dimoska
Aneta
A
Department of Psychology, University of Wollongong, Wollongong, Australia.
Johnstone
Stuart J
SJ
Barry
Robert J
RJ
Clarke
Adam R
AR
D000161:Acoustic Stimulation; D000704:Analysis of Variance; D001289:Attention Deficit Disorder with Hyperactivity / Q000503:physiopathology*; D001921:Brain / Q000503:physiopathology; D001931:Brain Mapping; D016022:Case-Control Studies; D002648:Child; D004192:Discrimination, Psychological; D004569:Electroencephalography / Q000379:methods; D004585:Electrooculography; D005071:Evoked Potentials / Q000502:physiology*; D006801:Humans; D007266:Inhibition, Psychological; D008297:Male; D009043:Motor Activity / Q000502:physiology*; D009483:Neuropsychological Tests; D010775:Photic Stimulation; D011594:Psychometrics; D011897:Random Allocation; D011930:Reaction Time; D014888:Wechsler Scales