- Circadian rhythms,
Cave study: Michel Siffre (1972) He spent
6 months living in a cave with no natural light.
- He was wired up so that some of his body functions could be recorded (EEG,EMG,EOG); he had a telephone and was monitored.
- Circadian rhythms
- Other rhythms: core body temp which dips just after lunch. Hormones like melatonin peaks during the hours of darkness and encourages feelings of sleep
- Circadian rhythms are a pattern of behaviour that occurs and recurs about every 24hrs, which is set and reset by environmental light levels
- Our circadian rhythms are driven by our internal body clock which is controlled by the suprachiasmatic nuclei (SCN) which is part of the hypothalamus
- Light provides the main input to the SCN which then coordinates the circadian system setting the body clock to the correct time
- The SCN acts as an ‘internal clock’ to keep the body in a 24hr sleep-wake cycle. The SCN sends messages to the pineal gland which produces melatonin
- The Cave study: Michel Siffre (1972) He spent 6 months living in a cave with no natural light.