Effect of Seat Angle when Sleeping in a Car on Quality of Sleep and Its Impact on Calculation Performance the Following Day

Hitomi Ogata; Tomohiro Nishikawa; Momoko Kayaba; Miki Kaneko; Keiko Ogawa; Ken Kiyono

doi:10.3390/ijerph191912270

Effect of Seat Angle when Sleeping in a Car on Quality of Sleep and Its Impact on Calculation Performance the Following Day

Int J Environ Res Public Health. 2022 Sep 27;19(19):12270. doi: 10.3390/ijerph191912270.

Authors

Hitomi Ogata¹, Tomohiro Nishikawa¹, Momoko Kayaba², Miki Kaneko³, Keiko Ogawa¹, Ken Kiyono³

Affiliations

¹ Graduate School of Humanities and Social Sciences, Hiroshima University, Hiroshima 739-8521, Japan.
² Department of Somnology, Tokyo Medical University, Tokyo 160-0023, Japan.
³ Graduate School of Engineering Science, Osaka University, Osaka 565-8531, Japan.

Abstract

The number of occasions to stay in a car overnight is increasing during disasters; however, the effects on sleep and the impact on daytime functioning are not well understood. We investigated the effect of seat angle when sleeping in a car and its impact on calculation performance the following day. Fifteen healthy males participated in three trials (sleeping in a car with the front seat angled at 45° and 60° in a laboratory and sleeping at home); sleep and calculation performance the following day were compared. Increased wake after sleep onset and decreased slow-wave sleep were observed in the 60° trial, that is, near-vertical, compared with the others. Subjective sleep quality and calculation performance in the 45° and 60° trials were poorer than those in the home trial. The effect of seat angle on sleep was confirmed objectively, but not subjectively, suggesting that a large seat angle might cause sleep impairment.

Keywords: calculation performance; seat angle; sleep architecture; sleeping in a car; subjective sleep quality.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Automobiles*
Humans
Male
Polysomnography
Sleep
Sleep Quality*

Grants and funding

This research was funded by the Ministry of Education, Culture, Sports, Science, and Technology (MEXT) Program Initiative for the Implementation of the Diversity Research Environment (Collaboration Type), Career Advancement Project for Women Researchers (CAPWR), Hiroshima University (2019).