Circadian Periodicity in Primates under Various Light - Dark Ratios.
Abstract
The activity of four rhesus monkeys (Macaca mulatta) was recorded for the purpose of appraising the effects of different light-dark (L:D) ratios upon circadian periodicity. Light-dark cycle was automatically scheduled, and temperature was held constant. Three L:D ratios (12:12, 6:18, and 18:6) were used. Consistent differential effects upon shape and amplitude of the circadian period, associated with the different L:D ratios, were observed. A high degree of photoperiodic dependency was demonstrated under the L:D = 18:6 schedule. Activity onset and cessation closely followed the onset and termination of the light period. A lesser degree of photoperiodic dependency was manifested by the L:D = 6:18 schedule, with activity starting 3-4 hours before the onset of light. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Jun 01, 1968
- Accession Number
- AD0742881
Entities
People
- Absalom Yellin
Organizations
- University of Delaware