Evidence Against Sleep’s Preferential Consolidation of Declarative Memory Associated With Future Retrieval: a Batchelor Degree Dissertation

This study compared whether expectancy for a future retrieval results in memory improvements after sleep. Participants learned declarative memories (word pairs) which was tested before and after a 12-hour retention interval that included a nocturnal sleep or daytime wake. Manipulation of retrieval expectancy was carried out prior to the retention, once the encoding and the immediate baseline test was completed, in which half of the groups were informed of the delayed retest. Retest results showed superior performance among participants who underwent sleep than wakefulness; however, the awareness for the delayed retest did not influence this outcome. The findings challenge the supposed role of future relevance and the active consolidation hypotheses of sleep.