title: Changes of the brain electrical fields during the continuous performance test in attention-deficit hyperactivity disorder-boys depending on methylphenidate medication.
abstract: OBJECTIVE
  The continuous performance test (CPT) is successfully applied to evaluate attentional performance in attention-deficit hyperactivity disorder (ADHD)-children. The aim of the present study was to investigate the changes of the topographic P300-features in relation to methylphenidate-medication and to different attentional processes in primer- and distractor-conditions.
  
  
  METHODS
  Twenty-one-channel-ERPs of 17 ADHD-boys were analyzed with reference-independent methods. Four quasi stable microstates within the time frames of conventional P100, P200, P3a and P3b components were identified by means of a data-driven segmentation procedure.
  
  
  RESULTS
  In segment 3 topographical assessment yielded a significant occipital and right-shift of the positive centroid, longer centroid distance and higher amplitudes in primer- than in distractor conditions. MPH increased the amplitude and distance in primer and distractor-condition, without changing the topography. In segment 4 the electric field strength of distractor-conditions collapsed, whereas the primer condition showed a strong fronto-parietally oriented potential-field. There was a tendency to higher amplitudes due to MPH-medication.
  
  
  CONCLUSIONS
  These results indicate a robust neurophysiologic differentiation of cognitive processes. MPH activates an early (P3a) covert attention process indicated by increased amplitudes and centroid. No effects were seen in later processes. Based on these effects, we propose to use the amplitude- and distance-increase in microstate 3 as an indicator of MPH efficacy in ADHD-boys.
authors.affiliation: EEG-Ep-Mapping Laboratory, Department of Child and Adolescent Psychiatry, University Hospital of Würzburg, Fuechsleinstrasse 15, 97080 Wuerzburg, Germany.
authors.forename: K E
authors.initials: KE
authors.lastname: Zillessen
authors.forename: P
authors.initials: P
authors.lastname: Scheuerpflug
authors.forename: A J
authors.initials: AJ
authors.lastname: Fallgatter
authors.forename: W K
authors.initials: WK
authors.lastname: Strik
authors.forename: A
authors.initials: A
authors.lastname: Warnke
mesh_terms: D000328:Adult; D001289:Attention Deficit Disorder with Hyperactivity / Q000188:drug therapy* / Q000523:psychology*; D001921:Brain / Q000502:physiology*; D000697:Central Nervous System Stimulants / Q000627:therapeutic use*; D004569:Electroencephalography; D018913:Event-Related Potentials, P300 / Q000187:drug effects / Q000502:physiology; D006801:Humans; D008297:Male; D008774:Methylphenidate / Q000627:therapeutic use*; D009483:Neuropsychological Tests; D011597:Psychomotor Performance / Q000502:physiology*
chemical_list: D000697:Central Nervous System Stimulants; D008774:Methylphenidate