Assessment of performance impairment after short naps with and without sleep inertia

Introduction Naps can reduce performance deficits and sleepiness, and therefore increase safety. However, sleep inertia – reduced functioning ability after awakening – may reduce the benefits of an otherwise effective sleep. Prior research shows that sleep inertia effects appear minimally after short naps. The aim of the study was to learn about laypersons' assessment of performance capacity following a short nap and ensuing sleep inertia. Method Two hundred and fifteen university students were divided into four groups who responded to questionnaires assessing performance levels of a character after a 15-min or a 60-min nap in imaginary scenarios. Tasks were to be executed immediately or an hour after waking from the nap. Respondents rated the extent of fitness of the character to complete each scenario. Results The ability to perform immediately after a 15-min nap was rated as low as after no sleep at all, and worse than immediately following a longer nap. It was also rated as worse than an hour after waking from a 15-min and a one-hour nap. Conclusion Laypersons are aware of the fact that insufficient sleep leads to impaired performance and that longer naps produce better functional recovery but are not aware of the dynamics of changes in the capacity to perform immediately after a nap. Practical Applications It is recommended that the gap between the knowledge people hold and the knowledge that is reflected in sleep research be reduced both through education in workplaces and mass media.