Event-related potential and looking-time analysis of infants' responses to familiar and novel events: Implications for visual recognition memory.

Event-related potentials (ERPs) and fixation duration were used to examine 6-mo-old infants' responses to frequently and infrequently presented familiar and novel events. ERPs, but not looking time, were found to distinguish between familiar events presented frequently vs infrequently and between familiar and novel events presented infrequently. It is proposed that the ERPs invoked by an infrequently presented familiar stimulus reflect the updating of working memory, whereas the ERPs invoked by a frequently presented familiar stimulus reflect stimulus encoding. Finally, because infants were unlikely to have formed a template for the novel events (each of which was presented only one time), the ERPs invoked by these stimuli probably reflected a nonspecific and possibly automatic process of novelty detection.