Circadian Rhythms and Psychology
Behavioral neuroscientists study circadian rhythms to understand the causes and consequences of temporal regulation at the molecular, systems, organismic and social levels of analysis. Circadian rhythms are relevent to the study of psychology in many ways.
- 1. Motivation: Circadian rhythms are a central concept for understanding why organisms do what they do when they do it. Circadian clocks modulate regulatory systems that control core motive states associated with basic needs for food, water and sleep.
- 2. Sensation: The circadian timekeeping system is a component of the visual system. In mammals, the master clock in the hypothalamus is innervated by the retina and contains neurons that code ambient light intensity. The retina itself contains a circadian clock, which modulates its own sensitivity to light across the day.
- 3. Perception: Circadian clocks affect the perception of hourly to daily intervals in animals and humans, and provide internal time cues that permit animals to discriminate, learn and remember times of day of optimal foraging, and to use the sun as a compass for navigation.
- 4. Cognition: Circadian rhythms modulate cognitive processes regulating attention and memory.
- 5. Human Performance and Ergonomics: Circadian constraints on sleep, arousal and cognition affect the performance and safety of humans working at non-optimal times of day, due to nightwork, rotating shiftwork, continuous operations, and transmeridian jet travel.
- 6. Behavioural Disorders: Circadian rhythms have been implicated in affective disorders, and alterations of circadian rhythms by genetic or environmental factors are a known cause of some sleep disorders.
- 7. Research Design: Circadian rhythms are a systematic, non-trivial source of variability in biology and behavior, and may represent a significant confound variable or source of statistical noise if not appropriately considered in research design.