PSYO 1021 Lecture Notes - Lecture 14: Circadian Rhythm, Glacier Cave, Pineal Gland
24 Dec 2015
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Document Summary
Our state of consciousness varies throughout the day due to circadian rhythms. In 1963, michael siffre spent 63 days underground inside a glacier cave without a watch, alone. He called a few teammates every time he woke up, ate, or went to sleep. Without light, we drift towards a free-running circadian rhythm of 24. 2-24. 8 hours: but as long as 48 hours! Circadian rhythms regulated by suprchiasmatic nuclei (scn: part of the hypothalamus. Scn neurons link to pineal gland, which secretes melatonin. Melatonin is a hormone that plays a role in relaxation and drowsiness. Neurons in scn are active during daytime: inhibits melatonin secretion, raises body temperature and alertness. Neurons in scn become inactive at night: allows melatonin secretion to increase, melatonin promotes relaxation and sleepiness. Habitual conflict between activity schedule and normal human circadian rhythms. Even daylight savings time increases risk, albeit slightly (coren, Changing patterns of brain-wave activity (eeg) help define the various stages of sleep.
