The ERP correlates of self-knowledge: Are assessments of one’s past, present, and future traits closer to semantic or episodic memory?
Louis Renoult1, Annick N. Tanguay2, Lauren Benton3, Lorenza Romio1, Carolin Sievers1, Patrick S. R. Davidson2; 1School of Psychology, University of East Anglia, Norfolk, UK, 2School of Psychology, University of Ottawa, Ontario, Canada, 3Department of Neuroscience, Dickinson College, Pennsylvania, USA
Self-knowledge entails evaluative judgments of oneself, and includes knowledge of one’s own traits and preferences. Self-knowledge is a type of personal semantics, yet it is unclear how it relates to semantic and episodic memory. Here, we compared the event-related potential (ERP) correlates of self-knowledge to those of semantic and episodic memory, using N400 and Late Positive Component (LPC) as proxies for semantic and episodic processing, respectively. We considered an additional factor: time perspective. Temporally distant selves may be more semantic compared to the present self, but thinking about one’s past and future selves may also engage episodic memory. Twenty-eight adults answered whether traits (e.g., persistent) were true of most people holding an occupation (e.g. soldiers; semantic memory condition), or true of themselves 5 years ago, in the present, or 5 years from now (past, present, and future self-knowledge conditions). The study ended with an episodic recognition memory task for previously seen traits. Mean N400 amplitudes for the 3 self-knowledge conditions were smaller than for semantic memory at sagittal sites. Present self-knowledge produced mean LPC amplitudes at posterior parietal sites that fell between semantic and episodic memory. Crucially, mean LPC amplitudes for past and future self-knowledge were greater than for semantic memory, and not significantly different from episodic memory. Overall, our findings are consistent with a distinction between knowledge of others and self-knowledge, but the closeness of self-knowledge’s neural correlates to either semantic or episodic memory appears to depend to some extent on time perspective.
Topic Area: LONG-TERM MEMORY: Episodic