|Budget Amount *help
¥5,500,000 (Direct Cost : ¥5,500,000)
Fiscal Year 1991 : ¥600,000 (Direct Cost : ¥600,000)
Fiscal Year 1990 : ¥800,000 (Direct Cost : ¥800,000)
Fiscal Year 1989 : ¥4,100,000 (Direct Cost : ¥4,100,000)
There have been few reports on the sleep structure of the blind and its general characteristics. Studies thus far have only focused on a few specific issues such as links between REM sleep and contents of a dream. One of the critical problems in these studies was that a somnogram was recorded from subjects sleeping in an unfamiliar experimental laboratory. These artificial surroundings set up for sleep research probably affected sleep processes, structures, and qualities in subjects studied. This has been called the "first night" effect.
In our present study, to minimize the disturbing effects of artificial settings on nocturnal sleep, our subjects could sleep in their home bed and-a telemetric somnographic system was used to measure EEGs and other physiological responses. The purpose of the present research was thus to make an overall analysis of nocturnal sleep structure in the blind under familiar and nonstressful conditions like sleeping in their home beds.
The research was conducted
from 1989 through 1992, and polysomnographic recordings were taken for three consecutive nights from visually handicapped subjects sleeping in their own home beds. A total of 21 subjects included 13 congenitally blind subjects(9 males and 4 females, mean age 28.1 years, range 18-61 years), 3 male non-congenital blind subjects(mean age 26.0 years, range 22-32 years), and 5 weak-sighted subjects(4 males and I female, mean age 39.0 years, range 20-53 years). Sleep stages were determined by visual reading of EEG, EMG, and EOG recordings. On each morning questionnaires were given to subjects to assess sleep qualities on a previous night. It was found that 1)slow wave sleep, i. e., stages 3 and 4, was significantly less, 2)intermittent awakenings during nocturnal sleep were observed significantly more often, and 3)wakefulness in the morning was significantly lower, in the visually handicapped than in normals. Finally, based on comparing the first night with the third night, the first night effect was not observed for any sleep parameters.
From the present findings it is suggested that further studies should be directed to the evaluation of factors such as duration and types of visual disturbance, aging, personality, and social aids. Less