||The cognitive construct of prospective memory (PM) refers to the capacity to encode,
retain and execute delayed intentions (e.g. to remember to buy milk on the way home).
Although previous research suggests that PM performance is enhanced by healthy
sleep, conclusions tend to be drawn based on designs featuring ecologically unnatural
manipulations (e.g. total sleep deprivation). This study investigates whether a more
common everyday experience (bedtime stress) affects next-day PM performance and,
in so doing, also contributes to the heretofore inconsistent literature on stress and PM.
Forty young adults received PM task instructions and were then assigned to either a
stress condition (exposure to a laboratory-based stress-induction manipulation; n = 20,
9 women) or a non-stress condition (exposure to a non-stressful control manipulation;
n = 20, 12 women). After completing the experimental manipulation, all participants had
their objective sleep quality measured over a full night of polysomnographic monitoring.
Upon awakening, they completed the PM task. Analyses detected significant betweengroup differences in terms of stress outcomes, sleep quality and PM performance:
Participants exposed to the manipulation experienced heightened signs of stress
(captured using a composite variable that included self-report, psychophysiological
and endocrinological measures), had longer sleep latencies and poorer sleep depth
and displayed significantly longer reaction times to PM cues. An interaction between
experimental condition (being exposed to the stressor) and disrupted sleep (longer sleep
latency) significantly predicted poorer next-day PM reaction time. We interpret these
findings as indicating that bedtime stress, which leads to heightened presleep arousal,
affects sleep processes and, consequently, the deployment of attentional resources
during next-day execution of a delayed intention.