Abstract:

The ERP components related to facial expression processing include P1 (80~120 ms), N170 (120~200 ms), EPN (Early Posterior Negativity, 200~300 ms) and LPP (Late Positive Potential, after 300 ms). These components represent different stage of facial expression process and thus have different mental meaning. P1 is sensitive to threaten-related face, such as fear, disgust and anger, reflects a quick and automatic detection to threatened stimuli. N170 implicates the automatic process to code the structure of expression. EPN reflects the selective attention to emotion information. This competent is also automatic in some conditions and can be modulated by emotional expression of different kinds and emotional scene. LPP that is affected by attention control represents the higher cognitive process. Future research should extend the understanding of these ERP components by exploring: (1) Whether P1 is affected by the extent of threat. (2) The impact of top-down factors on N170. (3) Whether the facial expression stimulus that can elicit EPN, but not N170 be treated as general emotional stimulus. (4) Whether the LPP also reflects certain level of automaticity. (5) Whether processing different type of expression (e.g. fear and disgust) is dissociative in ERPs?

Key words: facial expression process, P1, N170, EPN, LPP