DL

Psych101-sleep

Sleep and Sleep Deprivation

  • Importance of Sleep:

    • Quote from Janis Joplin emphasizes misconception about sleep.

    • Quote from President Bill Clinton highlights the impact of sleep deprivation on politicians.

Consciousness

  • Definition: Awareness of ourselves and our environments.

  • Distinction from Unconsciousness:

    • Brain processes external and internal information during sleep.

    • Ability to wake up easily from sleep.

Theories on Why We Need Sleep

  • Protection: Evolutionarily, sleep helps avoid dangers in darkness.

  • Restoration: Repairs body tissues and aids memory consolidation.

  • Growth: Growth hormone released by the pituitary gland during sleep.

Sleep Research

  • Genetic Variability: Individual differences in sleep needs; average sleep is about 9 hours without clocks.

  • Health Correlation: Those sleeping 7-8 hours tend to outlive sleep-deprived individuals.

  • Naps: Not a sign of laziness; help focus and improve decision-making.

Circadian Rhythm

  • Definition: Biological clock regulating body rhythms every 24 hours.

  • Influencing Factors:

    • Melatonin production regulated by light exposure.

    • Bright light inhibits melatonin and resets the biological clock.

Morningness vs. Eveningness

  • Stable Preferences: Individual differences in early or late day activity.

  • Research Findings: Different biological rhythms can affect sleep/wake cycles.

Measuring Sleep

  • Key Components:

    • EEG (brain waves), EOG (eye movement), and EMG (muscle tone) used for differentiation of sleep stages.

Sleep Stages

  • Sleep Cycle: Lasts approximately 90 minutes and consists of 4 stages.

    • Awake States:

      • Beta waves (high frequency during wakefulness).

      • Alpha waves (relaxation before sleep).

    • Stage Descriptions:

      • N1: Transition stage; mixed theta waves; experiences like falling sensations.

      • N2: Light sleep; sleep talking may occur; presence of sleep spindles and K-complexes.

      • N3: Deep sleep; delta waves prominent; most restorative, parasomnias may occur.

      • REM: Dream state; resembles waking brain activity; increased heart rate and breathing.

Learning and Memory Consolidation

  • REM & SWS: Different types of learning related to respective sleep stages.

    • Non-declarative memories linked to REM.

    • Declarative/explicit memories linked to SWS.

Sleep Disorders

  • Insomnia: Affects 10-15% of adults, linked to stress, depression, and substance use.

  • Narcolepsy: Spontaneous episodes of REM sleep; absence of neurotransmitter hypocretin may link to autoimmune factors.

  • Sleep Apnea: Intermittent breathing stoppage during sleep; frequently observed in overweight individuals.

Unique Features of Human Sleep

  • Humans have shorter, efficient sleep compared to other primates, with a significant proportion in REM sleep.

  • Shorter sleep patterns may have evolved to accommodate cognitive advancements and social functions.

Lucid Dreaming

  • Definition: Awareness and control during dreaming.

  • Associated Brain Activity: Increased brainwave activity in REM correlating with lucid awareness.

Parasomnias

  • Types: Includes sleep walking, talking, and night terrors.

  • Occurs notably during deep sleep phases (N3).

REM Sleep Behavior Disorder (RBD)

  • Inability to inhibit normal muscle paralysis during REM, resulting in acting out dreams.

  • Factors influencing development include age, gender, and association with neurodegenerative diseases.

Sleep Paralysis

  • A phenomenon affecting 3-6% of the population, causing temporary paralysis upon waking.

  • Often accompanied by hallucinations and a sense of fear.

Conclusion

  • Understanding sleep is crucial for mental and physical health; disorders and sleep deprivation can have significant impacts.