Infrequent dream recall associated with low performance but high overnight improvement on mirror-tracing.

People who habitually recall few dreams performed worse on a visuomotor task (mirror tracing) before sleep but showed greater overnight improvement than those who recall many dreams. The improvement in low recallers was linked to Stage 2 sleep rather than rapid eye movement sleep. The findings suggest that dreaming relates to visuomotor processes and that different levels of visuomotor skill engage distinct sleep-related consolidation mechanisms.

Study at a glance

Abstract

Although sleep facilitates learning and memory, the roles of dreaming and habitual levels of recalling dreams remain unknown. This study examined if performance and overnight improvement on a rapid eye movement sleep-sensitive visuomotor task is associated differentially with habitually high or low dream recall frequency. As a relation between dream production and visuospatial skills has been demonstrated previously, one possibility is that frequency of dream recall will be linked to performance on visuomotor tasks such as the Mirror Tracing Task. We expected that habitually low dream recallers would perform more poorly on the Mirror Tracing Task than would high recallers and would show less task improvement following a night of sleep. Fifteen low and 20 high dream recallers slept one night each in the laboratory and performed the Mirror Tracing Task before and after sleep. Low recallers had overall worse baseline performance but a greater evening-to-morning improvement than did high recallers. Greater improvements in completion time in low recallers were associated with Stage 2 rather than rapid eye movement sleep. Findings support the separate notions that dreaming is related to visuomotor processes and that different levels of visuomotor skill engage different sleep- and dream-related consolidation mechanisms.