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

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