A Comparison of Nighttime Sleepiness, Performance, and Body Temperature between Morning-Type and Evening-Type Persons
아침형과 저녁형 사람에서 야간의 졸리움, 수행 및 체온의 비교
Yoon, Jin-Sang;Kook, Seung-Hee;Shin, Il-Seon;Shin, Man-Sik;Choi, Young;Lee, Mu-Suk;Lee, Hyung-Young;
Department of Neuropsychiatry, College of Medicine, Chonnam National University;Department of Neuropsychiatry, College of Medicine, Chonnam National University;Department of Neuropsychiatry, College of Medicine, Chonnam National University;Department of Neuropsychiatry, College of Medicine, Chonnam National University;Department of Neuropsychiatry, College of Medicine, Chonnam National University;Department of Neuropsychiatry, College of Medicine, Chonnam National University;Department of Neuropsychiatry, College of Medicine, Chonnam National University;
Objectives: The main purpose of this study was to investigate the possible differences in sleepiness, performance, and body temperature during the night between morning(M) and evening(E) type subjects. Methods: After a survey study, to verify the validity and reliability of the Korean translation of the Home'' and $ddot{O}stberg''s$ Morningness-Eveningness Questionnaire(1976), 8 extreme M-type subjects(3males, 5 females) and 8 extreme E-type subjects(3 males, 5 females) were selected from the university student population who had participated in the survey study. All subjects underwent sleep latency test and a battery of performance tests at intervals of 2 hours through the night, from 23:00 to 07:00. Oral temperature of each subject was taken every hour from 21 : 00 to 8 : 00. Between the testing times, the experimenters ensured that subjects remained awake. Results: More profound sleepiness was found in the M-type compared to the E-type throughout the night, with significant differences in sleepiness occuring at 23:00 and 01:00 hours. Overall performance efficiency tended to be lower through, the night in the M-type than in the E-type on all tests. A difference in time of temperature minimum between the two types was not noteworthy. Rather, there appeared to be a substantial difference in temperature level during the declining phase, with the temperature of the M-type being lower than that of the E-type. Conclusions: These results indicate the existance of a temporal relationship between sleepiness, perfonnance and body temperature during night work. Since the M-type exhibited greater sleepiness and lower performance efficiency overnight than the E-type, it may be assumed that the E-type is more suitable for and tolerable to night work. There was some discussion of the limitations in generalizing these results together with some suggestions for future studies.