ps1009 - 7 states of consciousness

Lecture 7: States of Consciousness

  • Instructor: Brett Cochrane (prett.cochrane@abdn.ac.uk)

Agenda

  • Sleep

    • Phases and purpose it serves.

    • Brain activities during sleep.

  • Drugs

    • Various types of drugs and their effects.

  • Other Related Issues

    • Meditation, sleep disorders, etc.

Introduction to Sleep

Definition

  • Sleep is a naturally recurring state of altered consciousness characterized by:

    • Reduced sensory activity.

    • Total paralysis or suppression of voluntary muscle activity.

    • Distinct phases that serve various restorative and cognitive functions.

Why We Sleep

  • Physical Restoration: Includes tissue growth/repair, immune function, and waste removal.

  • Survival Advantage: Energy conservation, predator avoidance, and optimizing the environment.

  • Cognition Function: Memory reinforcement, decision-making, and problem-solving contributions.

Electrical Activity in the Brain

  • Neuronal firing generates electrical activity.

  • Measured using EEG, global electrical activity at different frequencies reflects activation of brain networks:

    • Focused States: Beta-waves (13-30 Hz)

    • Relaxed States: Alpha-waves (8-12 Hz)

Stages of Sleep

Stage 1 (Transition to Sleep)

  • Waves: Alpha to theta (4-8 Hz)

  • Attributes:

    • Some muscle tone maintained; occasional hypnic jerks.

    • Slow, rolling eye movements.

  • Functions: Transitional stage between wakefulness and sleep.

  • Duration: 1 to 7 minutes.

Stage 2 (Light Sleep)

  • Waves: Theta waves

  • Attributes:

    • Further muscle tone loss; eye movements stop.

    • Slower heart rate, breathing, body temperature drops.

  • Functions:

    • Sleep Spindle: Bursts of rapid brain activity that reinforce motor skills practiced while awake.

    • K-Complex: Large slow-wave bursts in response to external stimuli aiding in sleep retention.

  • Duration: 10-25 minutes.

Stages 3 and 4 (Deep Sleep)

  • Attributes:

    • Reduced muscle tone (but not absent).

    • Lowest heart rate, breathing, and blood pressure.

    • Delta waves (0.4-4 Hz).

  • Primary Functions:

    • Tissue repair/growth and hormone regulation.

    • Declarative memory consolidation: Reinforces knowledge.

    • Immune activation: Defense against illness/cancer.

    • Brain detoxification: Clear waste (like beta-amyloid), restore astrocyte energy.

  • Duration: 20-40 minutes.

REM Sleep

  • Attributes:

    • Rapid eye movements; muscle paralysis.

    • Brain activity resembles wakefulness (beta waves) combined with theta waves.

    • Incidence of vivid dreams with detailed narratives and emotional content.

  • Primary Functions:

    • Mental Simulation: Problem-solving, new association formation, and pattern recognition.

    • Emotional Regulation: Processing emotional memories, particularly negatives.

    • Integration: Combines memories, emotions, and contexts for adaptive responses.

  • Duration: 10-60 minutes.

Sleep Cycles

  • Sleep progresses through different stages cyclically throughout the night.

  • Cycle Stages: Wake, REM, N1, N2, N3.

Circadian Rhythm

Definition

  • Circadian rhythm: An internal clock regulating sleep/wake cycles.

Mechanism

  1. CLK Proteins: Promote wakefulness.

  2. PER Proteins: Promote sleep; inhibit CLK proteins as they accumulate.

  3. Cycle Influence: External cues (zeitgebers) like light, hunger, and noise affect CLK and PER dynamics.

Sleep Deprivation

REM Sleep Deprivation

  • Impairs problem-solving abilities and creativity.

  • Leads to emotional dysregulation and increased risk-taking.

Deep Sleep Deprivation

  • Causes severe health risks (brain/muscle deterioration, weakened immunity, impaired brain detoxification).

  • Results in memory deficits and learning difficulties.

Sleep Disorders

Definition

  • Sleep disorders disrupt normal sleep patterns, impacting sleep quality, timing, and duration.

Types of Sleep Disorders

  • Non-REM Parasomnia: Abnormal behaviors during non-REM sleep (e.g., sleepwalking, night terrors).

  • REM Parasomnia: Awareness during REM paralysis (e.g., sleep paralysis).

  • Dyssomnia: Affects the quality/timing of sleep (e.g., insomnia, narcolepsy).

Sleepwalking

Definition

  • Characterized by complex behaviors during deep sleep.

Observations in Sleepwalking

  • Increased cerebellum and PCC activity; reduced frontal/partietal activity relative to wakefulness.

Brian Thomas Night Terror Case Study

  • Incident: Brian acted out a nightmare and unintentionally strangled his wife during a night terror episode.

  • Result: He was acquitted due to involuntary actions linked to sleep disorder.

Altered States of Consciousness

Definition

  • Any condition of awareness significantly different from normal waking state.

Sources of Altered States

  • Achieved through sleep, drugs, meditation, and hypnosis.

Benefits of Altered States

  • Enhance creative problem-solving and emotional regulation.

  • Help break unproductive patterns and foster a sense of purpose.

Altered States and Religion

Practices Incorporating Altered States

  • Prayer, meditation, music, and dance contribute to religious ecstasy and existential exploration.

Historical Use

  • Psychedelics used in early societies for rites of passage and healing.

Meditation

  • Involves focusing on an object of concentration while maintaining physical stillness.

  • Regulates the brain's default mode network, enhancing awareness and cognitive control.

Drugs

Definition

  • Substances influencing motor, sensory, or cognitive experiences.

Categories of Drugs

  • Hallucinogens

  • Stimulants

  • Depressants

  • Common effects derived from neurotransmitters: dopamine, serotonin, endorphins, and oxytocin.

Drug Classifications

Drug Category

Effects

Examples

Depressants

Slows CNS, relaxation

Alcohol, Valium, Xanax

Stimulants

Increases brain activity, boosts energy

Caffeine, Nicotine, Cocaine

Hallucinogens

Alters perception, induces distortion

LSD, Magic mushrooms, PCP

Opioids

Pain relief, euphoria

Heroin, Morphine, Fentanyl

Cannabinoids

Alters mood and perception

Marijuana

Empathogens

Enhances empathy, social connection

MDMA

Stimulants

Definition

  • Substances accelerating brain processes, increasing alertness and energy.

  • Examples include caffeine, nicotine, and cocaine.

Risks

  • Can lead to anxiety, seizures, and tachycardia.

Depressants

Definition

  • Substances that slow brain and body processes, inducing relaxation.

  • Common options include alcohol, Xanax, and Valium.

Risks

  • Overdosing can lead to coma and respiratory depression.

Hallucinogens/Psychedelics

Definition

  • Substances causing perceptual changes and hallucinations.

  • Notable examples: LSD, magic mushrooms, and peyote.

Risks & Side Effects

  • Bad trips and hallucinogen-persisting perception disorder.

Psilocybin and Depression

  • Study findings show greater depression symptom reduction in psilocybin users versus SSRI group.

  • PSychedelic brain activity improved regulation of the default mode network.

State Dependent Memory

  • Phenomenon where recall is better in the same mental state as encoding.

  • Example: Participants learned material in states of intoxication or sobriety and were tested across the same states.

Anxiety and Performance

Yerkes-Dodson Law

  • Suggests an optimal anxiety level enhances performance.

  • Performance patterns indicate the need for a balance in anxiety levels for complex tasks.

Conclusions

  • Sleep is an essential altered state necessary for survival and cognitive function.

    • REM Sleep: Vital for learning and adaptation.

    • Deep Sleep: Essential for health, supporting cellular repair and immune function.

  • Humans have utilized drugs to modify consciousness for centuries, accessing new perspectives throughout history.

Next Week

  • Topic: Thinking and reasoning.