PSY 1101 Lecture Notes - Lecture 4: Circadian Rhythm, Jet Lag, Pineal Gland

• School: University of Ottawa
• Department: Psychology
• Course: PSY 1101
• Professor: Laine John

Document Summary

Consciousness- the continuous stream of thoughts, feelings, sensations and perceptions of which we are aware from moment to moment. Altered state of consciousness- a mental state other than ordinary waking consciousness, such as sleep, meditation, hypnosis or a drug-induced state. Circadian rhythm- within each 24-hour period, the regular fluctuation from high to low points of a bodily function, such as sleep/wakefulness. Ultradian: more than once a day: hunger, alertness, body temperature, heart beats, eyeblinks. Infradian: over longer than a day: menstrual cycle. Suprachiasmatic nucleus (scn)- tiny structure in the hypothalamus that controls timing of circadian rythms. The scn reacts to the amount of light coming in through the eye. At low levels of light, the scn signals to the pineal gland to release melatonin, which induces sleep. Light seems to play a large role in inducing these rhythms. Disruption- it"s believed that without external cues such as clocks and calendars, we would naturally cycle through a 25-hour sleep/wake cycle.