Q

AP PSYCH 2.9 Sleep and Dreaming

  • We sleep in cycles
  • Each sleep cycle involves transitions between four different stages of sleep
    • NREM (Non-Rapid Eye Movement) 1, 2, and 3
    • REM (Rapid Eye Movement)
  • Each stage involves different psychological and physical changes
  • Throughout the night we go through cycles approximately every 90-120 minutes

The Process

  • As we sleep, we transition to ‘deeper’ stages that are more internally active
  • NREM-3 gets shorter with every cycle
  • REM gets longer with every cycle
  • NREM-1 → NREM-2 → NREM-3 → NREM-2 → REM

NREM-1

  • 5-10 minutes
  • Light sleep
  • When in this stage, you may feel like you’re floating, falling, or tingling
  • Alpha waves

NREM-2

  • Stable transitional stage
  • 10-20 minutes
  • Harder to awaken
  • Theta waves

NREM-3

  • Deepest sleep
  • Hardest to awaken
  • Delta waves
  • Gets shorter throughout the night
  • The growth hormone is released during this phase
  • In this phase, the ‘body sleeps’
    • All NREM’s, to an extent, are sleep for the body
    • Sleepwalking and talking in one’s sleep also all occur in the NREM stages

REM

  • Rapid Eye Movement
  • Beta waves
  • Very internally active
  • Externally paralyzed
  • Dreams and nightmares occur in this phase
  • Memory synthesis
  • REM is like ‘sleep for the mind’

Sleep Theories

  • We spend roughly 1/3 of our lives asleep, but why?

Restoration Theory

  • Our bodies wear out during the day and use up resources
  • Sleep is necessary to restore these resources and reenergize the body
    • Sleep helps restore and repair muscles and brain tissue
    • Sleep supports growth

Adaptive Theory

  • Based on evolutionary approach
  • Sleep protects us
  • Sleep emerged first in animals who evolved to preserve energy
    • It protects us during times where movement is not valuable and removes us from considerable danger
  • Sleep helped animals adapt to their environments, helping them survive, meaning the trait/behavior was passed down

Cognitive and Information Processing Theories

  • Sleep helps us restore and rebuild our memories of the day’s experiences
    • Memory consolidation occurs during REM
  • Sleep deprives individuals struggle cognitively
    • REM deprivation studies show this
  • People from all ages remember prior day’s events better with a well-rested brain
    • Even rats remember how to get through a maze they learned the day before better when having slept well

Psychological Theory

  • Originated with psychoanalyst Sigmund Freud
    • He published “The Interpretation of Dreams” in 1900 on the subject
  • Proposed that dreams are the road to the unconscious mind
    • They’re filled with content we cannot face in conscious, waking life
  • Manifest and Latent content
    • The literal content of the dream and the implied meaning of it
  • Many modern psychological theories are similar to Freud’s original theory

Biological and Information Processing Theories

  • Dreams provide a way to sort out the day’s events and consolidate our memories for storage
  • Activation-Synthesis Model
    • REM helps preserve and develop neural connections
    • REM triggers neural activity in the cortex as memories are synthesized
    • Activation leads to synthesis

Sleep Disorders

  • We know that sleep restores, protects, rejuvenates, and helps us perform
  • But millions of people are sleep deprived, even knowing its value

Insomnia

  • The inability to fall or stay asleep, or both
  • Insomnia is the most common of all sleep disorders
  • Insomnia derives us not only of sleep, but of the many cognitive and physical benefits that sleep provides

Causes

  • Stress
  • Irregular sleep schedule
  • Pain/illness
  • Diet/medications

Treatment

  • Depends on the cause
  • Stress management
  • Medications/melatonin
  • Treatment of pain/illness
  • Changing habits

Sleep Apnea

  • Cessation of breathing while sleeping
  • Breathing stops repeatedly throughout the night
  • Snoring, gasping
  • Never feeling rested and restored even after a full night of sleep
  • There are three types
    • Obstructive
    • Central (CNS)
    • Complex

Causes

  • Risk factors include…
  • Weight
  • Smoking
  • Gender
  • Age
  • A thick neck
  • A narrow airway
  • Nasal obstruction

Treatment

  • Depends on the cause and type
  • Losing weight
  • A C-PAP machine

Narcolepsy

  • Falling into uncontrollable, deep sleep all throughout the day
  • Drowsiness
  • Muscles paralysis (cataplexy)
  • Immediately falling into REM sleep

Causes

  • Genetic
  • Damage to the reticular formation

Treatment

  • Medication
  • Support/accommodations