Reactivation and Consolidation of Memory During Sleep

ABSTRACT— Recent research has shown compellingly that sleep supports the consolidation of declarative memories for events and facts. During consolidation, memories are stabilized against future interference and undergo qualitative changes with regard to their "explicitness" and underlying neural representation. In this article, we argue that declarative memory consolidation during sleep is based on covert reactivations of newly encoded memory traces in the hippocampus. During slow-wave sleep (SWS), the prominent slow oscillations act to synchronize the repeated reactivation of the newly encoded representations in hippocampal networks with the generation of spindle activity in the thalamus, supporting changes in neocortical networks that contribute to long-term memory storage. In this view, sleep plays an active role in the consolidation of memories, in which the neuronal reactivation of newly acquired memories is critical for the redistribution and integration of these memories into the network of pre-existing long-term memories.     

Targeted Memory Reactivation During Sleep,But Not Wake,Enhances Sensorimotor Skill Performance: A Pilot Study

The benefits of sleep on memory consolidation have been enhanced for declarative and motor sequence learning through replaying classically conditioned auditory stimuli during sleep, known as targeted memory reactivation (TMR). However, it is unknown if TMR can influence performance of a sensorimotor skill, in the absence of the cognitive requirements of sequence learning. Here, young adults performed a nondominant arm throwing task separated by a full night of sleep or a full day of wake, with half of all participants receiving TMR between sessions. Participants who received TMR during sleep demonstrated enhanced sensorimotor performance relative to all other groups. In conclusion, this pilot study indicates that it is feasible to influence sensorimotor skill performance through TMR during sleep and may serve as a future adjunct to physical rehabilitation. Future studies will aim to confirm the present results with a larger sample size as well as investigate the effects of TMR during sleep on older adults both with and without a history of stroke.