Abstract
Objective: The aim of this study was to assess baseline EEG brain wave activity in
children with ADHD and to examine the effects of evoked attention and methylphenidate
on this activity.
Method: Children with ADHD (n=19) were tested while they were stimulant-free and
during a period in which they were on stimulant (methylphenidate) medication. Control
subjects (n = 18) were tested once. EEG brain wave activity was tested both at baseline
and during focussed attention. Attention was evoked and EEG brain wave activity was
determined by means of the BioGraph Infiniti biofeedback apparatus.
Results: The main finding of this study was that control subjects and stimulant-free
children with ADHD exhibited the expected reactivity in high alpha wave (11-12 Hz)
activity from baseline to focussed attention; however, methylphenidate appeared to
abolish this reactivity.
Conclusion: Methylphenidate attenuates the normal cortical response to a cognitive
challenge.