Time-on-task analysis using wavelet networks in an event-related potential study on attention-deficit hyperactivity disorder.
OBJECTIVE
The aim of this event-related potential (ERP) study was to test time-on-task analysis at the level of single sweeps in a clinical trial. Since inattentiveness is one of the main symptoms of attention-deficit hyperactivity disorder (ADHD), this child psychiatric disorder was chosen as an exemplary application.


METHODS
Twenty-four healthy and 24 ADHD boys, aged 9--15 years, performed an auditory selective attention task for about 5 min. ERP single trials were analyzed using wavelet networks. Time-on-task analysis was applied to omission errors, reaction time and slow ERP components (frontal negativity, parietal positivity), represented by a low-frequency wavelet component.


RESULTS
Both performance and ERP measures showed distinct temporal dynamics. Time-on-task effects were not only linear, but also of higher order and started after less than 1 min. For ADHD children, earlier time-on-task effects, i.e. an earlier increase of omission errors and frontal negativity, resulted. Healthy children could allocate more attentional resources during the course of the experiment.


CONCLUSIONS
Time-on-task analysis at the level of single trials revealed phenomena probably reflecting ADHD children's attentional deficits. Thus, a more differentiated ERP analysis may provide a better understanding of the pathophysiological background in neuropsychiatric disorders.
Heinrich
H
H
Child and Adolescent Psychiatry, University of Göttingen, v. Siebold-Strasse 5, D-37075 Göttingen, Germany. hheinri@gwdg.de
Moll
G H
GH
Dickhaus
H
H
Kolev
V
V
Yordanova
J
J
Rothenberger
A
A
D000161:Acoustic Stimulation; D000465:Algorithms; D001289:Attention Deficit Disorder with Hyperactivity / Q000523:psychology*; D002648:Child; D005071:Evoked Potentials / Q000502:physiology*; D005625:Frontal Lobe / Q000502:physiology; D006801:Humans; D008297:Male; D008959:Models, Neurological; D016571:Neural Networks, Computer; D010296:Parietal Lobe / Q000502:physiology; D011569:Psychiatric Status Rating Scales; D011597:Psychomotor Performance / Q000502:physiology*; D012815:Signal Processing, Computer-Assisted