自己覚醒が夜間睡眠と起床後の覚醒度に及ぼす影響 <学位論文要旨>

This doctoral dissertation aimed to assess the effects of self-awakening on arousal levels immediately after awakening and during the day, and to clarify the mechanisms underlying these effects. Chapter 1 includes the aims of this doctoral dissertation and a review of previous studies on self-awakening. Chapter 2 shows how self-awakening barely disturbs nocturnal sleep but reduces sleep inertia immediately after awakening. The data included in chapter 3 show that sigma band power gradually decreased during sleep stage 2 before self-awakening. The sigma band power reflects sleep spindle activity, which plays a role in maintaining sleep. These findings suggest that sleep maintenance gradually decreases before self-awakening and that this phenomenon decreases sleep inertia. Chapter 4 describes how self-awakening decreases daytime sleepiness and fatigue. Chapter 5 shows that the accuracy of time assessment during sleep increases when attempting self-awakening. This accurate time assessment during sleep may cause awakening from sleep at a predetermined time. Chapter 6 includes the conclusion, i.e., self-awakening is useful for preventing sleepiness in daily life and that attempting self-awakening, which enables accurate time estimation during sleep and reduces sleep maintenance before awakening, also enables the individual to accurately awaken at a predetermined time.