Mod 9 (part 1)

Introduction to Sleep and Dreams

• Sleep: A periodic loss of consciousness, distinct from other states like coma and anesthesia.

• Importance of Sleep: Vital for strengthening mind and body, memory retention, emotional regulation, and survival.

Biological Rhythms

• Circadian Rhythm: Internal biological clock linked to light and dark cycles.

• Effects of Circadian Rhythms:

  • Fluctuations in body temperature throughout the day:

    • Cooler at night, higher in the afternoon/evening.

  • Approximately 24-hour cycle with longer actual length based on studies.

Brain Activity During Sleep

• Sleep Researchers Measure:

  • Brainwave activity, eye movements, muscle tension using electrodes.

• Types of Brain Waves:

  • Beta Waves: Alert waking state.

  • Alpha Waves: Relaxed waking state.

  • N1 (Stage 1 Non-REM): Transition into sleep, characterized by quick brain waves.

  • N2 (Stage 2 Non-REM): Bursts of rapid rhythmic brainwave activity aiding memory processing.

  • N3 (Stage 3 Non-REM or Deep Sleep): Slow delta waves, essential for restorative processes.

  • REM Sleep: Paradoxical sleep with vivid dreams; body is typically relaxed with some twitching.

Sleep Cycles

• Sleep Patterns:

  • Younger adults typically experience a ~90-minute sleep cycle.

  • New parents might observe ~45-minute sleep cycles in infants.

• Typical Night Sleep Patterns:

  • Young Adults: Progression from awake to REM, through N1, N2, N3 stages multiple times.

  • Older Adults: More frequent awakenings; reduced time spent in REM sleep.

Microsleep and Hypnagogic Experiences

• Microsleep: Brief sleep episodes that can result in hallucinations without external stimuli.

• Hypnagogic Stage: Experiences occurring as one falls asleep; may include sensations such as floating or falling.

Importance of REM Sleep

• Functions of REM Sleep:

  • Associated with vivid dreaming and essential for memory consolidation.

  • If REM sleep is lost, subsequent cycles may result in increased REM periods.

Aging and Sleep Changes

• As individuals age, sleep becomes more fragmented with many awakenings and less REM time.

Factors Influencing Sleep Patterns

• Genetics and Culture: Can affect sleep requirements and habits.

• Exposure to Natural Light: Activates retinal proteins that influence SCN (suprachiasmatic nucleus) disrupting melatonin production.

  • Jet Lag: Affects the body’s biological clock when traveling across time zones, resulting in fatigue.

  • Social Jet Lag: Weekend schedule disruptions can lead to sluggishness.

Functions and Theories of Sleep

• Protective Function: Sleep evolutionarily kept humans safe during night hours.

• Recuperation: Neurological repair and restoration occur during sleep.

• Memory Formation: Sleep strengthens neural connections essential for memory.

• Stimulating Creativity: Sleep can enhance problem-solving and creative thought processes.

• Growth Hormone Release: Particularly during slow-wave sleep, promoting growth and muscle development.

Sleep Deprivation Consequences

• Effects:

  • Accumulation of sleep debt; cannot be corrected in one night.

  • Increased irritability, concentration issues, risk for mental health disorders, weight gain, and impaired immune response.

• College Students: Often report sleep deprivation and its associated impacts on energy and performance.

Sleep Improvement Strategies

• Create a Relaxing Environment:

  • Dark, cool room; minimize screen time before bed.

  • Develop a wind-down routine: warm baths, calming music, meditation, and deep breathing to reduce stress.

• Importance of Quality Sleep: Enhancing sleep quality can significantly impact overall health and well-being.