Psychology: Stages of Sleep & EMG

Sleep Stages

• Mnemonic: "BATS Drink Blood" represents sleep stages: Beta (awake), Alpha (drowsy), Theta (light sleep - stage 1), Spindles & K-complexes (stage 2), Delta (stages 3/4), and Beta (REM).
• A typical sleep cycle follows the order: stages 1, 2, 3, 4, then back through 4, 3, 2, and ending in REM. REM increases while deep sleep stages decrease over the cycle. Missing REM sleep leads to REM rebound.

Sleep States

• Awake State: Characterized by low-voltage, high-frequency beta waves.
• Relaxed/Drowsy State: Features low amplitude, high-frequency alpha waves ranging from 8-12 Hz.
• Stage 1 Sleep: Dominated by theta waves (4-7 Hz), EOG shows eye rolling, and EMG displays moderate activity.
• Stage 2 Sleep: Identified by K-Complex (large, slow waves) and sleep spindles (bursts of waves, 12-14 Hz). No eye movement and moderate EMG occur.
• Stage 3 Sleep: Characterized by slow delta waves, low frequency, decreased heart rate, reduced digestion, and secretion of growth hormone. Sleepwalking and night terrors can occur.
• REM Sleep: Presents beta-wave-like patterns; it’s a paradoxical sleep with no muscle movement and is where dreams and nightmares occur, thanks to the pons inhibiting motor function.

Sleep Regulation and Disorders

• Circadian Rhythm: Regulates the sleep-wake cycle through melatonin produced by the pineal gland.
• Dyssomnia: Refers to sleep disorders affecting sleep initiation, duration, or excessive sleepiness. Includes insomnia, narcolepsy, and sleep apnea.

Dream Analysis

• Manifest Content: The surface story of a dream, as per Freudian theory.
• Latent Content: The deeper underlying meaning of a dream, based on Freudian interpretation.

Hypnosis

• Overview: Hypnosis combines factual memories with fiction, can aid in healing certain conditions, but does not enhance memory.
• Theories:
  • Social Influence Theory: Hypnosis may involve participants acting out social roles.
  • Divided Consciousness Theory: Proposes hypnosis leads to a dissociated state of consciousness.

Psychoactive Substances

• Depressants: Substances like alcohol and barbiturates that reduce CNS activity.
• Opiates: Decrease CNS activity and interfere with REM sleep, leading to short-term memory loss.
• Stimulants: Includes caffeine, nicotine, and cocaine which all increase CNS activity.
• MDMA (Ecstasy): Elevates dopamine and serotonin levels and blocks serotonin re-uptake, which can lead to depressive states due to neuronal compensation.

Drug Addiction

• Involves heightened dopamine levels in the nucleus accumbens, promoting addictive behaviors.

Test your knowledge on the stages of sleep with the mnemonic 'BATS Drink Blood' and understand the importance of electromyography in evaluating skeletal muscle activity. This quiz covers essential concepts related to consciousness and physiological measurement techniques.