INTEREST in the problem of sleep and waking activity patterns of temperate zone man living in the polar regions stems from four principle considerations.

1. Persistent anecdotal reports of unusually frequent and persistent disturbances of sleep, primarily insomnia—dubbed "The Big Eye"—in polar living men from Europe and America.

2. Possible effects of seasonal, instead of diurnal, cycles of light and darkness upon the sleeping-waking cycle and the normal circadian rhythms.

3. Possible opportunity to learn what is the natural, biological requirement of man for sleep under conditions where he may sleep any part of the 24-hour cycle and as long as he likes, free from the usual social pressures limiting sleep, during a considerable part of the year.

4. Possible influence of a unique set of allegedly stressful environmental factors upon sleep patterns, duration, and quality, reflecting the adaptational methods and capacity of a given individual.

Scientific