Effects of a short midday nap on habitual nappers’ alertness, mood and mental performance across cognitive domains

Abstract

This study examines whether the benefits of a short midday nap on habitual nappers' mental performance depend on the cognitive domain and the task difficulty. Eighteen healthy college students with the long-term habit of a midday nap (13:00-14:00 hours) participated in a nap-deprivation study. On two separate days with at least 3 days in between, participants either took a nap or remained awake, and were subsequently tested on a simple sustained attention task (Psychomotor Vigilance Test), two more complex attention tasks (Go/No-Go and Flanker task) and one working memory task (2-back). For each task, an easy and a difficult version were administered. The time course of subjective sleepiness and mood were also measured in both napping conditions. The results revealed that short midday nap deprivation significantly impaired participants' performance on both the easy and difficult versions of the Psychomotor Vigilance Test task, as well as accuracy but not reaction speed in the Go/No-Go task. Accuracy in the difficult version of the Flanker task and the 2-back task was also lower in the no-nap condition, while reaction speed in the 2-back task but not the Flanker task was reduced without a nap in both the easy and difficult versions. Moreover, subjective sleepiness was significantly increased after nap deprivation, but moods remained unaffected in the no-nap condition. These findings contribute to current research suggesting that effects of a midday nap on task performance depend on the cognitive domain as well as task difficulty. Our study highlights the importance of considering task characteristics to evaluate the benefits of a regular midday nap in practical working life.

Does Bright Light Counteract the Post-lunch Dip in Subjective States and Cognitive Performance Among Undergraduate Students?

“…Regarding the task performance, the previous studies had revealed no consistent pattern of a post-lunch nap on task performance varied in different cognitive domains (5,9,10,23,59). The current findings even revealed an indicator and type of task-dependent impairment of nap deprivation on cognitive performance.…”

“…In some countries, such as in China, most university students are used to take a short post-lunch nap during working days. Multiple empirical studies have demonstrated that people taking a brief nap (20-40 min) would promote afternoon function including vigilance, sustained attention, executive functions, logic reasoning, memory, and learning performance (5,(7)(8)(9)(10)(11)(12), whereas a lost opportunity of midday nap would lead to various impaired effects on alertness, mood, and performance ability, especially for those who habitually takes a nap (7,(9)(10)(11).…”

Effects of Afternoon Nap Deprivation on Adult Habitual Nappers’ Inhibition Functions

“…Most of the current studies have restricted their tasks to a limited range of task difficulty levels. Hence, this may lead to an open question on whether the effect of a short nap or sleep on cognitive functions would be mediated simultaneously by the type of task and the task difficulty, which was preliminarily answered by one of our follow-up studies [ 49 ]. In this follow-up study, we mainly focus on the beneficial effects of habitual daytime nap on alertness, mood, and cognitive performance, while we put more emphasis on the undesirable influences of habitual daytime nap deprivation on alertness and inhibition functions in the current investigation.…”

Effects of bright light and an afternoon nap on task performance depend on the cognitive domain

“…Studies on how an afternoon nap affects alertness and task performance have revealed both positive (Brooks & Lack, 2006; Mantua & Spencer, 2017; Ru, Chen et al., 2019) and few (Chen et al., 2018; Zhang et al., 2009) effects. Several factors may explain these contradictory findings, such as manipulation of a nap (i.e., duration or timing) (Milner & Cote, 2009) and different tasks employed.…”