Abstract :
Emotional face encoding process was explored through electroencephalographic measures (event-related potentials [ERPs]).
Previous studies have demonstrated an emotion-specific cognitive process in face comprehension. However, the effect
of emotional significance of the stimuli (type of emotion) and task (direct or indirect task) on the ERP is uncertain.
In Experiment 1 (indirect task) ERP correlates of 21 subjects were recorded when they viewed emotional (anger, sadness and
happiness) or neutral facial stimuli. An emotion-specific cortical variation was found, a negative deflection at approximately
200 ms after simulus (N2 effect). This effect was sensitive to the emotional valence of faces, because it differentiated high
arousal emotions (i.e., anger) from low arousal emotions (i.e., sadness). Moreover, a specific cortical site (posterior) was
activated by emotional faces but not by neutral faces. In Experiment 2 (direct task), the authors investigated whether
encoding for emotional faces relies on a single neural system irrespective of the task, or whether it is supported by multiple,
task-specific systems. Differences in the cortical distribution (posterior for incidental task; central and posterior for direct
task) and lateralisation (right-distribution for the negative emotions in direct task) of N2 on the scalp were observed in the
different tasks. This indicates that distinct task-specific cortical responses to emotional focus can be detected with ERP
methodology.
