The effect of prior sleep on retrieval

Abstract

Sleeping immediately prior to learning impaires subsequent retention. The purpose of this study was to ascertain if relatively short-term (0 to 20 mins) retention deficits are the result of impaired retrieval at the time of testing. 24 young women students were randomly allocated to two groups: prior sleep and awake. The prior sleep group was required to generate (retrieve) instances of specified categories immediately upon awakening from the first hour or so of nocturnal sleep and repeated the task again after a delay of 20 minutes. The awake control group performed the task at exactly the same times of night but without having had any prior sleep. The prior sleep group retrieved significantly fewer category instances immediately upon awakening and at delayed testing. However, retrieval had significantly improved during the 20 mins delay. It was concluded that the detrimental effects of prior sleep on retention over relatively short intervals may in part be due to retrieval difficulties at the time of testing but that longer-term retention deficits (<20 mins) are more likely to be due to impaired memory consolidation.