Effects of the Effort to Fall Asleep on the Sleep Onset Process

Abstract

Difficulty in falling asleep could be caused by physiological and cognitive arousal, including anxiety and worry. However, it is unclear which part of the sleep onset process is affected by cognitive arousal. This study examined the effects of the effort to fall asleep on the sleep onset process represented by nine EEG stages. Healthy male university students (N=9, aged 21 to 23 years) without any sleep-related complaints participated in the study on two experimental nights. They were instructed to sleep when they felt sleepy (Neutral condition) or try to sleep as soon as possible (Effort condition). Results indicated the prolonged EEG Stage 1(the alpha wave train) and Stage 4(EEG flattening) in the Effort condition. These results suggest that the effort to fall asleep affects only the early part of the sleep onset process in which the arousal system has reduced activity.