2 research outputs found
The nature of delayed dream incorporation (âdream-lag effectâ): Personally significant events persist, but not major daily activities or concerns
Incorporation of details from waking life events into rapid eye movement (REM) sleep dreams has been found to be highest on the 2 nights after, and then 5â7 nights after, the event. These are termed, respectively, the dayâresidue and dreamâlag effects. This study is the first to categorize types of waking life experiences and compare their incorporation into dreams across multiple successive nights. Thirtyâeight participants completed a daily diary each evening and a dream diary each morning for 14 days. In the daily diary, three categories of experiences were reported: major daily activities (MDAs), personally significant events (PSEs) and major concerns (MCs). After the 14âday period each participant identified the correspondence between items in their daily diaries and subsequent dream reports. The dayâresidue and dreamâlag effects were found for the incorporation of PSEs into dreams (effect sizes of .33 and .27, respectively), but only for participants (n = 19) who had a belowâmedian total number of correspondences between daily diary items and dream reports (termed âlowâincorporatorsâ as opposed to âhighâincorporatorsâ). Neither the dayâresidue or dreamâlag effects were found for MDAs or MCs. This Uâshaped timescale of incorporation of events from daily life into dreams has been proposed to reflect REM sleepâdependent memory consolidation, possibly related to emotional memory processing. This study had a larger sample size of dreams than any dreamâlag study hitherto with trained participants. Coupled with previous successful replications, there is thus substantial evidence supporting the dreamâlag effect and further explorations of its mechanism, including its neural underpinnings, are warranted