E M Bekker1, J L Kenemans, M N Verbaten. 1. Department of Psychopharmacology, Utrecht University, Sorbonnelaan 16, P.O. Box 80082, 3508 TB Utrecht, The Netherlands. e.m.bekker@pharm.uu.nl
Abstract
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. SIGNIFICANCE: Electrophysiological measures can greatly enhance our understanding of normal and abnormal information processing during continuous performance and related tasks.
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. SIGNIFICANCE: Electrophysiological measures can greatly enhance our understanding of normal and abnormal information processing during continuous performance and related tasks.
Authors: Connie Lamm; Olga L Walker; Kathryn A Degnan; Heather A Henderson; Daniel S Pine; Jennifer Martin McDermott; Nathan A Fox Journal: Dev Sci Date: 2014-04-22