Discrimination of emotional facial expressions in a visual oddball task: an ERP study.
Several ERP studies have shown an orienting complex, the N2/P3a, associated to the detection of stimulus novelty. Its role consists in preparing the organism to process and react to biologically prepotent stimuli. Whether this N2/P3a: (1) could be obtained with complex visual stimuli, such as with emotional facial expressions; and (2) could take part in a complex discrimination process has yet to be determined. To investigate this issue, event-related potentials were recorded in response to repetitions of a particular facial expression (e.g. sadness) and in response to two different deviant (rare) stimuli, one depicting the same emotion as the frequent stimulus, while the other depicted a different facial expression (e.g. fear). As expected, deviant stimuli evoked an N2/P3a complex of larger amplitude than frequent stimuli. But more interestingly, when the deviant stimulus depicted the same emotion as the frequent stimulus the N2/P3a was delayed compared to the response elicited by the different-emotion deviant. The N2/P3a was thus implicated in the detection of physical facial changes, with a higher sensitivity to changes related to a new different emotional content, perhaps leading to faster adaptive reactions.
Campanella
S
S
Unité de Neurosciences Cognitives (NESC), Faculte de Psychologie, Université Catholique de Louvain, Place du Cardinal Mercier 10, B-1348, Louvain-la-Neuve, Belgium. salvatore.campanella@psp.ucl.ac.be
Gaspard
C
C
Debatisse
D
D
Bruyer
R
R
Crommelinck
M
M
Guerit
J-M
JM
D000328:Adult; D001143:Arousal / Q000502:physiology*; D001288:Attention / Q000502:physiology*; D001931:Brain Mapping; D002540:Cerebral Cortex / Q000502:physiology; D004193:Discrimination Learning / Q000502:physiology*; D004292:Dominance, Cerebral / Q000502:physiology; D004569:Electroencephalography; D004644:Emotions / Q000502:physiology*; D005074:Evoked Potentials, Visual / Q000502:physiology; D005149:Facial Expression; D005260:Female; D006801:Humans; D008297:Male; D010364:Pattern Recognition, Visual / Q000502:physiology*; D012815:Signal Processing, Computer-Assisted