Event-related wave activity in the EEG provides new marker of ADHD.
OBJECTIVE
This study examines the utility of new measures of event-related spatio-temporal waves in the EEG as a marker of ADHD, previously shown to be closely related to the P3 ERP in an adult sample.


METHODS
Wave activity in the EEG was assessed during both an auditory Oddball and a visual continuous performance task (CPT) for an ADHD group ranging in age from 6 to 18 years and comprising mostly Combined and Inattentive subtypes, and for an age and gender matched control group.


RESULTS
The ADHD subjects had less wave activity at low frequencies ( approximately 1 Hz) during both tasks. For auditory Oddball targets, this effect was shown to be related to smaller P3 ERP amplitudes. During CPT, the approximately 1 Hz wave activity in the ADHD subjects was inversely related to clinical and behavioral measures of hyperactivity and impulsivity. CPT wave activity at approximately 1 Hz was seen to "normalise" following treatment with stimulant medication.


CONCLUSIONS
The results identify a deficit in low frequency wave activity as a new marker for ADHD associated with levels of hyperactivity and impulsivity.


CONCLUSIONS
The marker is evident across a range of tasks and may be specific to ADHD. While lower approximately 1 Hz activity partly accounts for reduced P3 ERPs in ADHD, the effect also arises for tasks that do not elicit a P3. Deficits in behavioral inhibition are hypothesized to arise from underlying dysregulation of cortical inhibition.
Alexander
David M
DM
The Brain Resource International Database, Brain Resource Company, Sydney, Australia. dalex@brain.riken.jp
Hermens
Daniel F
DF
Keage
Hannah A D
HA
Clark
C Richard
CR
Williams
Leanne M
LM
Kohn
Michael R
MR
Clarke
Simon D
SD
Lamb
Chris
C
Gordon
Evian
E
D000161:Acoustic Stimulation / Q000379:methods; D000293:Adolescent; D000704:Analysis of Variance; D001289:Attention Deficit Disorder with Hyperactivity / Q000175:diagnosis* / Q000188:drug therapy / Q000503:physiopathology*; D001931:Brain Mapping; D000697:Central Nervous System Stimulants / Q000627:therapeutic use; D002648:Child; D003913:Dextroamphetamine / Q000627:therapeutic use; D004307:Dose-Response Relationship, Radiation; D004569:Electroencephalography; D018913:Event-Related Potentials, P300 / Q000187:drug effects / Q000502:physiology*; D005260:Female; D006801:Humans; D008297:Male; D008774:Methylphenidate / Q000627:therapeutic use; D009483:Neuropsychological Tests; D010775:Photic Stimulation / Q000379:methods; D013057:Spectrum Analysis
D000697:Central Nervous System Stimulants; D008774:Methylphenidate; D003913:Dextroamphetamine