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.