Scientific Article
previous document  unige:11840  next document
add to browser collection

Arousal and valence effects on event-related P3a and P3b during emotional categorization

Silvert, Laetitia
Hot, Pascal
Rigoulot, Simon
Sequeira, Henrique
Published in International Journal of Psychophysiology. 2006, vol. 60, no. 3, p. 315-322
Abstract Due to the adaptive value of emotional situations, categorizing along the valence dimension may be supported by critical brain functions. The present study examined emotion-cognition relationships by focusing on the influence of an emotional categorization task on the cognitive processing induced by an oddball-like paradigm. Event-related potentials (ERPs) were recorded from subjects explicitly asked to categorize along the valence dimension (unpleasant, neutral or pleasant) deviant target pictures embedded in a train of standard stimuli. Late positivities evoked in response to the target pictures were decomposed into a P3a and a P3b and topographical differences were observed according to the valence content of the stimuli. P3a showed enhanced amplitudes at posterior sites in response to unpleasant pictures as compared to both neutral and pleasant pictures. This effect is interpreted as a negativity bias related to attentional processing. The P3b component was sensitive to the arousal value of the stimulation, with higher amplitudes at several posterior sites for both types of emotional pictures. Moreover, unpleasant pictures evoked smaller amplitudes than pleasant ones at fronto-central sites. Thus, the context updating process may be differentially modulated by the affective arousal and valence of the stimulus. The present study supports the assumption that, during an emotional categorization, the emotional content of the stimulus may modulate the reorientation of attention and the subsequent updating process in a specific way.
Keywords AdultAnalysis of VarianceArousal/physiologyBrain MappingCognition/physiologyElectroencephalography/methodsEmotions/physiologyEvoked Potentials/physiologyFemaleHumansPhotic Stimulation/methodsReaction Time/physiology
Stable URL
Full text
Article (Published version) (314 Kb) - document accessible for UNIGE members only Limited access to UNIGE
PMID: 16226819
151 hits and 1 download since 2010-09-13
Export document
Format :
Citation style :