Temporal features of individual and collective self-referential processing: an event-related potential study

Background: Individual and collective self are two fundamental self-representations and are important to human experience. The present study aimed to investigate whether individual and collective self have essential difference in neural mechanism. Methods: Event-related potentials were recorded to explore the electrophysiological correlates of individual and collective self in a self-referential task in which participants were asked to evaluate whether trait adjectives were suitable to describe themselves (individual self-referential processing), a famous person (individual non-self-referential processing), Chinese (collective self-referential processing) or American (collective non-self-referential processing). Results: At the early stages, results showed that larger P2 and smaller N2 amplitudes were elicited by individual self-referential than by individual non-self-referential processing whereas no significant differences were observed between collective self-referential and collective non-self-referential processing at these stages. In addition, at the late P3 stage (350-600 ms), larger P3 amplitudes were also elicited by individual self-referential than by individual non-self-referential processing during 350-600 ms interval. However, the collective self-reference effect, indicated by the differences between collective self-referential and collective non-self-referential processing, did not appear until 450 ms and extended to 600 ms. Moreover, individual self-reference effect was more pronounced than collective self-reference effect in the 350-500 ms interval, whereas individual and collective self-reference effect had no significant difference in the 500-600 ms interval. These findings indicated that the time courses of neural activities were different in processing individual and collective self.