PSY 1101 Lecture Notes - Lecture 5: Circadian Rhythm, Rapid Eye Movement Sleep, Sleep Spindle

• School: University of Ottawa
• Department: Psychology
• Course: PSY 1101
• Professor: Mark Dallas

Document Summary

Relates to light; retina > suprachiasmatic nucleus (regulates clock by responding to light and triggering:) > pineal gland (increase/decrease melatonin) Evolutionary very old structures -- when we need to sleep, we need to! We are awake during the day, vs nocturnal. Light levels and day/night cycles -- changes body temp. too. Also affected by age, genes (nocturnal owls, larks up in morning), environment (shift work), culture (siesta) Circadian rhythm regulates alertness -- best 9-10am, worst by ~3pm -- explains why shift worker on call doesn"t enter rem sleep. Sleep occurs in 5 stages of 90m cycles, either rem or nrem. Different brainwaves at each stage (technology can detect -- eeg) Awake and alert > awake and drowsy > nrem1 > 2 > 3 > 4 > rem. Nrem1 falling asleep -- hypnagogic sleep, transition into full sleep (may feel like falling/gloating, hallucinatory sleep) Nrem2, real sleep begins with sleep spindles, waves become more slowed after k complex .