Event-related potentials differentiates the processes involved in the effects of sleep on recognition memory

This study examined the role of sleep on event‐related potential (ERP) indicators of memory following sleep and wake. We expected a larger ERP effect due to a facilitory effect of sleep on memory. During the study session, subjects memorized a series of stimuli (faces). At test, after a retention interval characterized by either sleep or by normal waking activities, subjects were asked to recognize old items intermixed with new. Results revealed differences in the old/new effect whereby the amplitude between old/new items was larger after sleep versus wake, suggesting a role of sleep in consolidation. Retention over sleep versus wake was associated with modified early and late frontal and posterior components possibly manifesting reduced interference inhibition, increased contextual processing, and facilitation of episodic memory. These findings suggest that ERP indices are differentially affected by sleep, reflecting differences in memory processing.