Recognition of sleep paralysis among normal adults in Canada and in Japan.

There were no differences between Canada and Japan in the prevalence and symptoms of sleep paralysis (SP), but many more Canadians considered SP to be a dream. The difference was considered to be derived from the fact that there is a common expression for SP in Japan but there is not one in Canada. Then, we investigated why there are individuals who consider SP to be a dream and others who do not, and found that many Japanese who regarded it as a dream did not report the symptom of 'unable to move', while in Canada, self-evaluation of spirituality was different between the two groups.