A new US study has found that good quality sleep promotes more effective ‘prospective memory’, that is, the capacity to remember to do something in the future. Sleep’s role in memory formation and consolidation has been the target of various previous scientific investigations, but the Washington University St Louis study is one of the first to distinguish the type of memory that specific phases of sleep support. Earlier studies also focused primarily on ‘learned’ memories and how ingrained they were after sleep, rather than ‘future’ memory in this case.
Prospective memory works largely via a series of associations that are formed between things in daily life, and these connections allow for sights, sounds and thoughts to ‘trigger’ related memories when required. Associations can be ‘strong’, for instance obviously linked, or ‘weak’, in which they would be loosely connected. A person’s ability to reliably call on weak associations would mean that they had a better prospective memory compared to someone who could only use strong associations.
“We found that sleep benefits prospective memory by strengthening the weak associations in the brain, and that hasn’t been shown before,” said Dr. Mark McDaniel.
“We think that during slow-wave sleep, the hippocampus is reactivating these recently learned memories, taking them up and placing them in long-term storage in the brain,” added researcher Michael Scullin.
The results of the study were published in the journal Psychological Science.