Electrophysiological correlates of attention, inhibition, sensitivity and bias in a continuous performance task.
OBJECTIVE
The aim was to verify the occurrence of proposed electrophysiological correlates of attention, inhibition, sensitivity and bias in a continuous performance task and to support their functional interpretation by using a manipulation intended to enhance subjects' response bias.


METHODS
Electroencephalographic activity was recorded during administration of a transformed version of the AX continuous performance task in which cues signaled response alternatives.


RESULTS
The previously reported parietal P3, NoGo-N2, NoGo-P3 and contingent negative variation were replicated. Besides, the frontal selection positivity and the lateralized readiness potential were demonstrated. With increasing Go-probability, the parietal P3 to the cue increased without changes in other cue-related correlates. In addition, reaction times decreased, non-parametric measures of sensitivity and bias decreased, the NoGo-N2 increased, and the parietal Go-P3 decreased.


CONCLUSIONS
The proposed electrophysiological correlates were identified. Sub-threshold LRPs suggested a central inhibition mechanism. Cue-related correlates revealed that anticipation of a high-probability Go-stimulus involves attention rather than bias. This implies that the increased NoGo-N2 reflected an increase in conflict rather than an increase in inhibition.


CONCLUSIONS
Electrophysiological measures can greatly enhance our understanding of normal and abnormal information processing during continuous performance and related tasks.
Department of Psychopharmacology, Utrecht University, Sorbonnelaan 16, P.O. Box 80082, 3508 TB Utrecht, The Netherlands. e.m.bekker@pharm.uu.nl
E M
EM
Bekker
J L
JL
Kenemans
M N
MN
Verbaten
D000328:Adult; D001288:Attention / Q000502:physiology*; D003265:Contingent Negative Variation / Q000502:physiology*; D004576:Electromyography; D005074:Evoked Potentials, Visual / Q000502:physiology*; D006801:Humans; D009433:Neural Inhibition / Q000502:physiology*; D011336:Probability; D011597:Psychomotor Performance / Q000502:physiology*; D011930:Reaction Time / Q000502:physiology