Consciousness: Sleep, Dreams, and Psychoactive Drugs

Consciousness

Definition and States

• Consciousness refers to our subjective experience of the world, our bodies, and our mental perspectives (waking consciousness).

• Altered states of consciousness include sleep paralysis, locked-in syndrome, out-of-body experiences, near-death experiences, mystical experiences, hypnosis, meditation, and the effects of psychoactive drugs.

Sleep and Circadian Rhythms

Circadian Rhythm

• A circadian rhythm is a biological rhythm that occurs over a 24-hour cycle (e.g., sleep, hunger, concentration).

• Regulated by the suprachiasmatic nucleus (SCN) of the hypothalamus, also known as the biological clock.

• The sleep-wake cycle is linked to the natural light-dark cycle of the environment.

• Body temperature, hormone production, and blood pressure follow circadian rhythms.

The Suprachiasmatic Nucleus (SCN)

• The SCN is the brain's clock mechanism.

• It synchronizes with the outside world using light information received from the retina.

What is Sleep?

• Characterized by low physical activity and reduced awareness.

• Associated with the secretion of hormones such as melatonin, follicle stimulating hormone, luteinizing hormone, and growth hormone.

Stages of Sleep

• Sleep occurs in 5 stages, cycling every 90 minutes.

• Stages 1-4: Non-REM (NREM) sleep; no eye movements, fewer dreams.

• Stage 5: REM sleep; vivid dreams and rapid eye movements.

Stage 1: Transition

• Transition from wakefulness to sleep (10-15 minutes).

• Brain waves slow down; dreams are like photos.

Stage 2: Falling Asleep

• Further slowing of brain waves.

• Presence of sleep spindles and K-complexes (may help maintain sleep and memory storage).

• Comprises up to 65% of total sleep; lasts around 20 minutes.

Stages 3 and 4: Deep Sleep

• Characterized by delta waves.

• Crucial for feeling rested; growth hormone production increases.

• Children spend more time in these stages than the elderly.

• Suppressed by alcohol; stage 4 is the hardest to awaken from.

Stage 5: REM Sleep

• Rapid eye movement; brain waves resemble wakefulness.

• Muscle atonia (paralysis); only eyes and inner ear muscles move.

• REM rebound occurs after deprivation; likely essential for health.

Hypnagogic State: Pre-Sleep Consciousness

• Occurs as one transitions into sleep.

• Features hypnagogic imagery (visual, somatic, auditory) and myoclonic/hypnic jerks.

Functions of Sleep

Why Do We Sleep?

• Adaptive (Preserve & Protect Hypothesis): Sleep restores resources and protects from predatory risks, but increases vulnerability.

• Restorative (Restore & Repair Hypothesis): Sleep restores and replenishes the body, consolidates memory, supports learning, and cognitive function (especially during slow-wave sleep).

• Essential for growth and brain development.

Sleep Deprivation and Displacement

Sleep Deprivation

• Degeneration of neurons in the brainstem; ADHD-like symptoms.

• Increases risk of physical illness, family problems, and substance abuse.

• Lack of sleep can impair performance similar to a blood alcohol concentration (BAC) of 0.07.

Sleep Displacement

• Occurs when sleep is prevented at the normal time (e.g., jet lag, caffeine before bed).

• Can delay the internal clock and disrupt sleep quality.

Disruptions of Normal Sleep

• Jet lag: Mismatch between internal circadian cycles and environment (fatigue, sluggishness, irritability).

• Rotating shift work: Difficult to maintain circadian rhythm; leads to exhaustion, agitation, sleep problems, depression, and anxiety.

• Bright light can help realign the biological clock.

Effects of Shift Work

• Shift work can age the brain by more than 6 years and reduce cognitive function.

• Lower scores on memory, processing speed, and overall brain power.

• Effects are reversible (~5 years to recover).

Daylight Savings Time & Car Accidents

• Changes in sleep patterns due to daylight savings time are associated with increased car accidents.

Sleep Deprivation & Mental Health

• Increased stress, emotional overreaction, and impaired emotional regulation.

• Biological basis: amygdala activation without frontal cortex regulation.

Case Study: Peter Tripp

• Stayed awake for 200 hours; experienced hallucinations, paranoia, and personality changes.

• Demonstrates severe effects of sleep deprivation.

Sleep Hygiene for Students

• Maintain a regular sleep-wake schedule.

• Ensure a quiet sleep environment.

• Avoid caffeine after lunch and stimulating activities before bed.

• Use the bed only for sleep; get up if not tired.

Sleep Disorders

Insomnia

• Difficulty falling or staying asleep for at least 3 nights a week for at least 1 month.

• Affects 9-20% of people; higher among students (~25%).

• Associated with ADHD, depression, and employment stress.

• Treatment: psychotherapy and/or hypnotics (e.g., Lunesta, Ambien); concerns about tolerance and side effects.

Paradoxical Insomnia

• Sleep-state misperception: belief of being sleep deprived despite normal sleep cycles.

• Causes distress, anxiety, and fatigue; linked to brain activity during sleep.

Night Terrors & Sleep Apnea

• Night terrors: Sudden waking episodes with screaming, sweating, and confusion; most common in children (ages 3-8), generally harmless.

• Sleep apnea: Blockage of the airway during sleep; associated with risks such as SIDS (sudden infant death syndrome).

Narcolepsy

• Rapid and unexpected onset of sleep, directly into REM sleep.

• Includes cataplexy (sudden loss of muscle tone).

• Associated with lack of orexin (a neurotransmitter).

Other Sleep Disorders

• REM behaviour disorder: Not paralyzed during REM; can act out dreams.

• Somnambulism (sleepwalking): Walking while fully asleep, occurs during stage 3 sleep; safe to wake the person.

Dreams: Function and Meaning

Freud's Theory

• Dreams as unconscious wish fulfillment.

• Latent content: Hidden psychological meaning.

• Manifest content: Actual storyline of the dream.

• Freud believed dreams symbolically represent unconscious desires, but only about 10% are sexual in nature.

Evolutionary Theory

• Problem-solving theory: Dreams help process daily concerns and stressful events, allowing for continuous information processing.

• Example: Kurdish children had more intense and frequent threatening dreams than Finnish children, reflecting environmental stressors.

Neuroscience Theory

• Activation-synthesis theory: Dreams are the brain's attempt to make sense of random neural activity during sleep.

• Dream content reflects the dreamer's fears, emotions, and concerns.

• Motivational and emotional centers (e.g., limbic system) are active during REM, with less activation of the prefrontal cortex.

Psychoactive Drugs

Definition and Effects

• Psychoactive drugs contain chemicals similar to those found naturally in the brain, altering neurotransmission.

• They influence emotions, perceptions, and behaviors, and can create physiological or psychological dependence.

Stimulants

• Speed up nervous system activity, enhancing wakefulness and alertness.

• Caffeine: Most commonly used; blocks adenosine, increasing alertness.

• Cocaine: Small doses produce euphoria and energy; large doses can cause irritability and aggression. Blocks dopamine reuptake, flooding the brain with dopamine.

• Amphetamines: Strong stimulants (e.g., Dexedrine, Benzedrine, methamphetamine); stimulate dopamine release, can cause neurological and physical problems, and alter brain structure.

• ADHD Medications: Drugs like Adderall and Vyvanse increase dopamine, serotonin, and norepinephrine; improve wakefulness and coping in ADHD, but can cause euphoria in non-ADHD users.

• MDMA (Ecstasy): Both a stimulant and hallucinogen; increases serotonin, heightens sensations, and social bonding. Chronic use can alter brain structure.

Hallucinogens (Psychedelics)

• Produce hallucinations or changes in perception (e.g., LSD, psilocybin, ayahuasca, marijuana, ecstasy, salvia).

• Interest in therapeutic value for mystical experiences and treatment-resistant conditions.

• MDMA & LSD: MDMA increases empathy and connection; LSD produces vivid hallucinations and alters sensory perception and time.

Marijuana (THC: Tetrahydrocannabinol)

• Effects are a mix of excitatory, depressive, and hallucinogenic.

• Triggers spontaneous, unrelated ideas, distorted perceptions, and increased sensitivity to stimuli.

• Impaired memory and cognitive function; can induce psychosis in vulnerable individuals.

• Modern cannabis contains much higher THC levels than in the past.

Depressants

• Reduce arousal and stimulation by decreasing neurotransmission and electrical activity.

• Includes alcohol, opioids, benzodiazepines; used to treat anxiety, panic, and sleep disorders.

Alcohol

• Most commonly used depressant; stimulating at low doses, depressant at higher doses.

• Lowers inhibition, impairs judgment, and magnifies emotions.

• Females experience stronger effects due to body composition.

• Balanced-placebo design: Expectations can influence social behavior as much as physiological effects.

BAC (%)	Effects
0.01-0.05	Behavior and judgment slightly affected, not intoxicated
0.03-0.12	Blurred vision, slurred speech, impaired coordination
0.09-0.25	Alcohol poisoning, senses severely impaired
0.25-0.35	Coma risk, compromised respiration and circulation
0.45+	Alcohol poisoning may cause death

Sedatives

• Barbiturates: Induce sleep or relaxation; addictive and dangerous with alcohol.

• Benzodiazepines: Treat anxiety and panic; highly addictive, can cause tolerance and memory impairment, deadly with alcohol.

• Quaaludes (Methaqualone): CNS depressant, increases GABA; banned due to high abuse potential.

Opioids

• Derived from poppy seeds; bind to opioid receptors, producing euphoria and pain relief.

• Includes prescription drugs (oxycodone, morphine, fentanyl) and illegal drugs (heroin).

• Highly addictive; can cause respiratory depression and overdose.

• Cycle of addiction: drug use shifts from seeking pleasure to avoiding withdrawal.

Sleep Paralysis and Culture

Sleep Paralysis

• Occurs when waking up or going into/out of REM sleep.

• Characterized by being conscious but unable to move, often accompanied by anxiety, terror, and hallucinations (e.g., intruder, chest pressure).

• Cultural interpretations influence the experience (e.g., "Old Hag" in Newfoundland, "Kanashibari" in Japan, "Top-hat man" in recent years, "Pandafeche" in Italy).