Afternoon naps can improve prospective memory performance by strengthening cue monitoring

Afternoon naps can alleviate drowsiness, enhance alertness, and restore attentional resources. Prospective memory (PM) involves memory to perform future actions. Although numerous studies have found that nighttime sleep benefits PM, the question of whether afternoon naps improve PM remains unclear. This study uses the multinomial process tree (MPT) model to investigate the effect of afternoon naps on PM and its components. This study included 55 participants, who were randomly assigned to two groups: the experimental group (n = 28) and the control group (n = 27). The experimental group was required to take a 30-minute nap, while the control group performed filler tasks for 30 min. The pre-test was conducted 10 min after waking up from the nap, while the post-test was 3 h after waking up. The results revealed that afternoon nap only facilitated PM performance on the post-test. Participants in the experimental group had slower responses to ongoing tasks and PM tasks, reflecting the enhancement of control processing and supporting the preparatory attention processing and memory processing theory. Finally, the results of MPT model revealed that afternoon nap promoted the prospective component of PM but had no effect on its retrospective component. These suggest that afternoon naps mainly boost cue monitoring in PM rather than intention retrieval.