Incorporation of fragmented visuo-olfactory episodic memory into dreams and its association with memory performance
Jane Plailly, Manon Villalba, Raphael Vallat, Alain Nicolas, Perrine Ruby
Scientific Reports October 30, 2019 DOI: 10.1038/s41598-019-51497-y (opens in new tab)
Study at a glance
AI-extracted from the abstract| Characteristics | Experimental study Peer reviewed |
|---|---|
| Sample size | 32 |
| Population | High dream recallers |
| Duration | 3 consecutive days of exploration, with dream recording during subsequent nights and memory testing on the 4th day |
| Keywords | Dream Episodic memory Association psychology Memory consolidation Perception Odor Cognitive psychology Audiology Cognition Hippocampus |
| Citations | 42 |
| Key findings | Participants with learning-related dreams had significantly better visuo-spatial memory of the episodes compared to other participants, while odor recognition and odor-evoked episodic memory were similar. |
Abstract
Abstract The question of a possible link between dream content and memory consolidation remains open. After a comprehensive review of the literature, we present novel findings from an experiment testing whether the incorporation of recently learned stimuli into dream reports is associated with improved post-sleep memory performance. Thirty-two high dream recallers freely explored new visuo-olfactory episodes for 3 consecutive days. During the nights following each non-explicit encoding, participants wore a wrist actimeter, and woke up at 5am and their usual waking time to record their dreams (intensity of all oneiric sensory perception was assessed using scales). A total of 120 dreams were reported and elements related to the encoding phase were identified in 37 of them, either learning-related (mainly visual- and rarely olfactory-related elements), or experiment-related (lab- or experimenters-related elements). On the 4 th day, we found that participants with learning-related (n = 16) and participants with learning-related and/or experiment-related dreams (n = 21) had similar odor recognition and odor-evoked episodic memory with the other participants. However, they had significantly better visuo-spatial memory of the episodes in comparison to the other participants. Our results support the hypothesis that the learning phase is loosely incorporated into dreams and that this incorporation is associated with sleep related memory consolidation.