Circadian rhythm

Consciousness: Some occur spontaneously: Daydreaming, drowsiness, dreaming. Some are physiologically: Hallucination, orgasm, food or oxygen, starvation. Some are psychologically induced: Sensory deprivation, hypnosis, meditation. Bodily Rhythms Biological Rhythms: periodic physiological fluctuations Grizzly bears hibernating Sleep length Female menstrual cycle 24-hour day cycle (alertness) 90-minute sleep cycle Circadian Rhythms: biological clock that regulates bodily rhythms on a 24-hour cycle. Influenced by LIGHT -> causes our pineal gland to increase or decrease production of melatonin. With age, we shift from night owls to morning birds. What would happen if a person was put into a cave for a long period of time without any light? The body works on a natural 25-hour clock.