Sleep to implement an intention

Abstract

Study objectives: Sleep supports the consolidation of new memories. However, this effect has mainly been shown for memories of past events. Here we investigated the role of sleep for the implementation of intentions for the future.

Design: Subjects were instructed on a plan that had to be executed after a delay of 2 days. After plan instruction, subjects were either allowed to sleep or stayed awake for one night (Exp. 1) or had a 3-h sleep period either during the early night (SWS-rich sleep) or late night (REM-rich sleep; Exp. 2). In both experiments, retesting took place 2 days later after one recovery night.

Setting: Sleep laboratory.

Patients or participants: A total of 56 healthy young adults participated in the study.

Interventions: N/A.

Measurements and results: All of the subjects who were allowed to sleep after plan instruction executed the intention 2 days later, whereas only 61% of wake subjects did so (P = 0.004; Exp. 1). Also after early SWS-rich sleep all of the subjects remembered to execute the intention, but only 55% did so after late REM-rich sleep (P = 0.015; Exp. 2).

Conclusions: Sleep, especially SWS, plays an important role for the successful implementation of delayed intentions.

Figure 1

Illustration of the experimental setup and results. (A) Experimental task. In the initial plan induction session, subjects performed on the vigilance task first, before the experimental plan was induced. At retesting after 2 days, it was recorded whether or not subjects executed the plan (i.e., to inform the experimenter about the wrong version). (B) Experimental design of Exp. 1 (sleep vs. wakefulness, upper panel) and Exp. 2 (SWS-rich early nocturnal sleep vs. REM-rich late nocturnal sleep, lower panel). PI (Plan induction), R (Retest). (C-D) Percentage of subjects executing the plan in Exp. 1 and Exp. 2. (E) Time spent in SWS and REM sleep in Exp. 2. Means ± SEM are shown. *P < 0.05, **P < 0.01, ***P < 0.001.