PSYCH 100 Lecture Notes - Lecture 22: Theta Wave, Hypnic Jerk, Sleep Spindle
Adeline Mahoney
Lecture 22- Psychology 100- Sleep
Biological Rhythms and Sleep
● Circadian Rhythms is another term for our biological clock
○ It occurs on a 24 hour cycle
○ It can be altered by artificial light
● Sleep Stages
○ Measuring sleep- can be measured by and EEG
■ About every 90 minutes we pass through a cycle of distinct sleep stages
● Awake
○ When you are alert and awake, we see fast beta waves (BAT D)
○ When an individual closes his eyes but remains awake
○ Brain activity slows down- alpha waves appear
● Sleep stage N1 (theta waves)
○ Transition from alpha to theta waves
○ Light sleep, hypnic jerk (twitching in sleep), hypnagogic images (visual dreams,
vivid images)
● Stage N2 (sleep spindles)
○ Temperature, breathing and heart rate decrease
● Sleep stage N3
○ Growth hormones released
○ Hard to wake up
● REM sleep
○ After reaching the deepest sleep stage (N3)
○ Starts moving backwards towards stage 1
Document Summary
Circadian rhythms is another term for our biological clock. It occurs on a 24 hour cycle. It can be altered by artificial light. Measuring sleep- can be measured by and eeg. About every 90 minutes we pass through a cycle of distinct sleep stages. When you are alert and awake, we see fast beta waves (bat d) When an individual closes his eyes but remains awake. Brain activity slows down- alpha waves appear. Light sleep, hypnic jerk (twitching in sleep), hypnagogic images (visual dreams, vivid images) After reaching the deepest sleep stage (n3) Although, still asleep, the brain engages in low- amplitude, fast and regular beta waves. Exhibits rapid eye movements (rem) and reports vivid dreams. Increase amount of rem sleep if deprived of rem sleep on earlier nights. With each 90-minute cycle, stage 4 sleep decreases and the duration of rem sleep increases. We spend one-third of our lives sleeping.
