The Role of Brief Afternoon Nap in Autonomic Nervous System

• Main Authors: Ya-Chuan Hsu, 徐雅娟
• Other Authors: Cheryl C.H. Yang
• Format: Others
• Language: zh-TW
• Published: 2011
• Online Access: http://ndltd.ncl.edu.tw/handle/06014783740892743645

碩士 === 國立陽明大學 === 腦科學研究所 === 99 === Background: A brief afternoon nap has positive effects on restoring physical and mental state of healthy individuals. However, most previous studies used self-assessment questionnaires and short-term functional evaluation, in which long-term effects and objective physiological measurements were neglected. Autonomic activity is an objective physiological indicator that can reflect various physical and mental states of an individual. Parasympathetic and sympathetic activity can reflect intensity of sleepiness and alteration in vigilance respectively. The application of heart rate variability (HRV) analysis has recently gained popularity in quantifying autonomic nervous system (ANS) functions non-invasively. Hypothesis: We hypothesizes that autonomic nervous system response is different between habitual nappers (HNs) and non-habitual nappers (nHNs) in one nap condition. Materials and Methods: HNs and nHNs were undergoing nap and non-nap condition in random order. The subjective measurement was taking before and after the nap or non-nap condition. The physiological signals were recorded for 24 hours using TD1A (miniature polysomnography). Autonomic function was assess using spectral analysis of HRV, in which the high frequency power (HF 0.15-0.4 Hz) represents cardiac parasympathetic activity and the normalized low frequency power (LF%) represents sympathetic activity. Results: The daily rhythmic oscillation of the autonomic activity had suggested the same results of subjective assessments that napping had significant effect on the autonomic function. Although HF was significantly increased in both HNs and nHNs during napping, the magnitude of the increase was greater in nHNs. For HNs, HF component of HRV during the first hour after the experimental condition was higher in the non-nap condition than nap condition. Conclusions: Our results show that: (1) The autonomic effect of afternoon nap is difference between HNs and nHNs. (2) They can provide an objective autonomic nervous system indicator for the effects of afternoon napping.