Event-related slow-wave activity in two subtypes of attention-deficit/hyperactivity disorder.
OBJECTIVE
Previous time-frequency studies have indicated that event-related low-frequency activity has important effects on component topography and developmental effects in auditory event-related potentials (ERPs) of children and adolescents. This study investigated the influence of event-related slow-wave (SW) (0.01-2 Hz) activity in the group differences seen between children with and without attention-deficit/hyperactivity disorder (AD/HD) of different subtypes.


METHODS
Time-frequency analysis techniques were applied to auditory ERP data derived from children with AD/HD predominantly inattentive type (n = 30), AD/HD combined type (n = 30) and age-matched control subjects (n = 30).


RESULTS
Event-related early frontal negative and late posterior positive SW components were reduced in the AD/HD combined type group, but not AD/HD inattentive type group, relative to controls. The RESIDUAL ERPs, which represented event-related 2-12 Hz activity, showed clinical vs. control group differences in components that were similar in both AD/HD subtype groups.


CONCLUSIONS
The time-frequency results showed that event-related SW (0.1-2 Hz) activity contributes importantly to group differences between AD/HD and control children, and the pattern of group differences from controls for each of the AD/HD subtype groups, which are evident in raw ERPs. These results emphasise both the clinical and developmental importance of this form of analysis.


CONCLUSIONS
This novel approach revealed additional specific information about stimulus processing and regional inhibition/activation in two AD/HD subtypes, relative to control subjects.
Johnstone
Stuart J
SJ
Brain & Behaviour Research Institute, University of Wollongong, Wollongong 2522, Australia. sjohnsto@uow.edu.au
Barry
Robert J
RJ
Dimoska
Aneta
A
D000293:Adolescent; D001289:Attention Deficit Disorder with Hyperactivity / Q000145:classification / Q000175:diagnosis* / Q000503:physiopathology*; D002648:Child; D005072:Evoked Potentials, Auditory; D005260:Female; D006801:Humans; D008297:Male; D011930:Reaction Time / Q000502:physiology