1 / 13

PSYC 1000

PSYC 1000. Lecture 23. Sleep and Dreams. Circadian Rhythm Biological clock Regular bodily rhythms that occur on 24 hour (approximately) cycle wakefulness, body temperature, … “Peak” period: Evening to Morning shift with age Jet lag: bright light helps to reset biological clock Sleep

khoi
Download Presentation

PSYC 1000

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript


  1. PSYC 1000 Lecture 23

  2. Sleep and Dreams • Circadian Rhythm • Biological clock • Regular bodily rhythms that occur on 24 hour (approximately) cycle • wakefulness, body temperature, … • “Peak” period: Evening to Morning shift with age • Jet lag: bright light helps to reset biological clock • Sleep • Periodic, natural, reversible loss of consciousness • Stages of Sleep • Different forms of brain activity • REM (Rapid Eye Movement) Sleep • Recurring sleep stage, Vivid dreams • “Paradoxical sleep”: Muscles are generally relaxed, but other body systems are active

  3. Sleep and Dreams • Measuring sleep activity

  4. Brain Waves and Sleep Stages • Alpha Waves • Slow waves of a relaxed, awake brain • Delta Waves • Large, slow waves of deep sleep • Hallucinations • False sensory experiences • Hypnogogic

  5. The Sleep Cycle • Rapid eye movement (REM) • Occur at periodic intervals during sleep cycle (after stages 1-4), lasts ~ 10 minutes • Associated with dream-like mental activity • Originally called paradoxical sleep • Non-REM (NREM) • Lower levels of activity • First 4 stages of sleep cycle (~ 90 minutes) • Go through entire cycle 4-6 times, where NREM decreases and REM increases throughout night

  6. Typical Nightly Sleep Stages

  7. Why do we Sleep? • Considerable variation in duration of sleep across individuals and species • Sleep debt accumulates across 2 weeks or more of deprivation • Sleep Deprivation • Dement (1997): 80% of students sleep deprived • Many negative effects of Sleep Loss • Fatigue • Impaired Concentration • Immune Suppression • Irritability • Slowed Performance • Accidents: planes, cars and trucks, …

  8. Species Variation in Sleep

  9. Sleep Deprivation

  10. Why Do We Sleep? • There are two main functions associated with why we need sleep: • Conservation • Sleep evolved because it allowed animals to conserve energy • Restoration • NREM occurs to provide an opportunity to repair and restore brain cells • REM is necessary for normal functioning and involved in the consolidation of learning and memory

  11. Sleep Disorders • Insomnia • Chronic failure to get adequate sleep • Includes inability to fall asleep, frequent arousals during sleep, or early-morning awakening • Canadian prevalence of ~ 13% • Narcolepsy • Irresistible compulsion to sleep during daytime • Associated with cataplexy & automatic REM states • Canadian prevalence of ~ 1/2000

  12. Sleep Disorders • Night Terrors • Experience of terror and increased arousal during transition from stage 3 to 4 of sleep • Appearance of being awake but non-responsive • Most common in children • Sleep Apnea • Disorder where person stops breathing during sleep & awakes to catch their breath • Hormonal response in body kicks in when oxygen deprived • Prevalence ~ 2% of adults

  13. Sleep Disorders • Somnambulism • Sleepwalking in which people leave their beds and wander while still remaining asleep • More frequent in children (7%) than adults (2%) • Associated with NREM sleep

More Related