Chapter 4

Chapter 4: Consciousness

Learning Objectives

• LO 4.1: Definition and levels of consciousness

• LO 4.2: Importance of sleep and its mechanisms

• LO 4.3: Stages of sleep and the dreaming process

• LO 4.4: Impact of sleep disorders on normal sleep

• LO 4.5: The purpose of dreams and dream content

• LO 4.6: Effects of hypnosis on consciousness

• LO 4.7: Differences between physical and psychological drug dependence

• LO 4.8: Effects and dangers of stimulants and depressants

• LO 4.9: Effects and dangers of hallucinogens

• LO 4.10: Consciousness and perceptions of supernatural events

Consciousness

• Definition: Awareness of everything happening around an individual at a given moment.

• Waking consciousness: Clear and organized state with alert thoughts, feelings, and sensations.

Altered States of Consciousness

• Altered state of consciousness: Changes in the quality or pattern of mental activity compared to waking consciousness.

Necessity of Sleep

• Circadian Rhythm: 24-hour cycle regulating bodily functions—"circa" (about) + "diem" (day).

• Hypothalamus: Brain area influencing sleep patterns via the suprachiasmatic nucleus, setting the internal clock for sleep.

  • Melatonin: Hormone secreted by the pineal gland, inducing sleepiness.

• Microsleeps: Brief episodes of sleep lasting seconds.

• Sleep deprivation: Leads to irritability and concentration issues.

Sleep Theories

• Adaptive Theory: Sleep evolved to avoid predation by aligning with predator activity.

• Restorative Theory: Sleep is vital for physical health, restoring chemicals and repairing cellular damage.

Stages of Sleep

• REM Sleep: Rapid eye movement sleep associated with dreaming; paradoxical sleep with high brain activity.

• NREM Sleep: Non-REM stages not characterized by rapid eye movement.

Brain Wave Patterns

• EEG: Monitors brain wave activity, which varies by sleep stage:

  • Alpha Waves: Indicate relaxation/light sleep.

  • Theta Waves: Early stages of sleep.

  • Delta Waves: Deepest sleep.

Sleep Stages Overview

• N1 (R&K Stage 1): Light sleep; may include hypnagogic images and hypnic jerks.

• N2 (R&K Stage 2): Characterized by sleep spindles.

• N3 (R&K Stages 3 and 4): Deep sleep marked by 50%+ delta waves; body functions at its lowest level.

• REM Sleep: High brain activity, where dreaming occurs; REM rebound leads to increased REM sleep after deprivation.

Sleep Disorders

• Nightmares: Disturbing dreams during REM.

• REM Behavior Disorder: Loss of muscle control allows acting out of dreams.

• Sleepwalking (somnambulism): Moving during deep sleep, prevalent in children.

• Night terrors: Severe fear episodes in deep sleep, with no full awakening.

• Insomnia: Difficulty falling or staying asleep.

• Sleep Apnea: Pauses in breathing, often treated with CPAP.

• Narcolepsy: Sudden onset of REM sleep during wakefulness; can include cataplexy.

Dreams

• Freud's Dream Theory: Dreams serve as wish fulfillment, distinguishing between manifest (story) and latent (underlying meaning) content.

• Activation-Synthesis Hypothesis: Dreams result from the brain interpreting random signals during REM sleep.

• Activation-Information-Mode Model (AIM): Dreams assimilate experiences and information accessed while awake.

Hypnosis

• Definition: A heightened state of suggestibility and focused attention.

• Four Elements of Hypnosis:

  1. Focus on the hypnotist’s voice.

  2. Relaxation and tiredness.

  3. Acceptance of suggestions.

  4. Use of vivid imagination.

• Hypnotic Susceptibility: Tendency to become easily hypnotized.

Theories of Hypnosis

• Dissociation Theory: One part of consciousness remains aware while another part is hypnotized.

• Social-Cognitive Theory: Hypnotized individuals are acting out expected roles.

Psychoactive Drugs

• Definition: Drugs affecting thought, perception, and memory.

• Physical Dependence: Characterized by tolerance (need for increased dosage) and withdrawal symptoms (nausea, pain, etc.).

• Psychological Dependence: Emotional need for drug to maintain well-being.

Stimulants and Depressants

• Stimulants: Increase nervous system activity (e.g., amphetamines, cocaine, nicotine, caffeine).

• Depressants: Decrease nervous system functioning (e.g., barbiturates, benzodiazepines, alcohol).

Hallucinogens and Marijuana

• Hallucinogens: Change perception and produce hallucinations (e.g., LSD, PCP, MDMA).

• Marijuana: Mild hallucinogen causing relaxation and altered perception; derived from hemp.

Hallucinations

• Hypnagogic Hallucination: Occurs when entering N1 sleep.

• Hypnopompic Hallucination: Occurs when transitioning from REM to wakefulness.