Consciousness: Sleep, Dreams, and Psychoactive Drugs – Study Notes

Consciousness

Definition and States

Consciousness refers to our subjective experience of the world, our bodies, and our mental perspectives. It encompasses both waking consciousness and altered states.

• Waking consciousness: Awareness of self and environment.

• Altered states: Sleep paralysis, locked-in syndrome, out-of-body experiences, near-death experiences, mystical experiences, hypnosis, meditation, and effects of psychoactive drugs.

Sleep and Circadian Rhythms

Circadian Rhythm

Circadian rhythms are biological cycles that occur over approximately 24 hours, regulating sleep, hunger, concentration, and other physiological processes.

• Regulation: Controlled by the suprachiasmatic nucleus (SCN) in the hypothalamus, which acts as the brain's clock mechanism.

• Synchronization: SCN receives light information from the retina, allowing alignment with the external environment.

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

What is Sleep?

Sleep is a state of low physical activity and reduced awareness, associated with the secretion of several hormones.

• Key hormones: Melatonin, follicle stimulating hormone, luteinizing hormone, growth hormone.

Stages of Sleep

Sleep occurs in 5 stages, cycling every 90 minutes. Stages 1-4 are NREM (non-rapid eye movement) sleep, and stage 5 is REM (rapid eye movement) sleep.

• Stages 1-4 (NREM): No eye movements, fewer dreams.

• Stage 5 (REM): Vivid dreams, quick eye movements.

Hypnagogic State

The transition from wakefulness to sleep, often accompanied by hypnagogic imagery (visual, somatic, auditory) and myoclonic/hypnic jerks.

Stage 1: Transition

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

• Brain waves slow down.

• Dreams may resemble photographs.

Stage 2: Falling Asleep

• Further slowing of brain waves.

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

• Accounts for 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 elderly.

• Suppressed by alcohol.

• Stage 4 is the hardest to awaken from.

Stage 5: REM Sleep

• Rapid eye movement; brain waves similar to wakefulness.

• Antonia (muscle paralysis); only eye and inner ear movements.

• REM rebound: increased REM after deprivation.

• Considered essential for health.

Why Do We Sleep?

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

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

• Essential: Necessary for growth and brain development, though the full reasons remain unclear.

Sleep Deprivation and Displacement

Sleep Deprivation

• Degeneration of neurons in the brainstem.

• ADHD-like symptoms.

• Increased risk of physical illness, family problems, substance abuse.

• Effects similar to blood alcohol concentration (BAC) of 0.07.

Sleep Displacement

• Prevented from sleeping at the normal time (e.g., jet lag).

• Consuming caffeine before bedtime delays the internal clock.

Disruptions of Normal Sleep

• Jet lag: Mismatch between internal circadian cycles and environment, causing fatigue and irritability.

• Rotating shift work: Changes in work schedule disrupt circadian rhythm, leading to exhaustion, agitation, sleep problems, depression, and anxiety.

• Bright light can help realign biological clock with external environment.

Effects of Shift Work

• Ages the brain by more than 6 years.

• Decline in memory, processing speed, and overall brain power.

• 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 and emotional reactivity.

• Lack of emotional regulation due to biological factors (amygdala activation without frontal cortex regulation).

Case Study: Peter Tripp

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

• Died at 73 of a stroke.

Sleep Hygiene for Students

• Regular sleep-wake schedule.

• Quiet sleep environment.

• Avoid caffeine after lunch and stimulating activities before bed.

• Don't stay in bed if not tired; don't use bed for non-sleep activities.

Sleep Disorders

Insomnia

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

• 9–20% of people experience insomnia; higher among students (~25%).

• Associated with ADHD, depression, employment stress.

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

Paradoxical Insomnia

• Sleep-state misperception: belief of sleep deprivation despite normal sleep cycle.

• Distress, anxiety, fatigue; cause unclear but linked to brain activity during sleep.

Night Terrors & Sleep Apnea

• Night terrors: Sudden waking episodes with screaming, sweating, confusion; most common in children (3–8), usually harmless.

• Sleep apnea: Blockage of airway during sleep; associated with SIDS (Sudden Infant Death Syndrome).

Narcolepsy

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

• Cataplexy (sudden loss of muscle tone).

• Associated with lack of orexin (neuropeptide).

Other Sleep Disorders

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

• Somnambulism: Walking while fully asleep; vague consciousness; occurs in stage 3 sleep; safe to wake.

Dreams

Freud's Theory

• Dreams as unconscious wish fulfillment.

• Latent content: Hidden psychological meaning.

• Manifest content: Actual storyline of the dream.

• Symbolic interpretation (e.g., objects in dreams may represent unconscious desires).

Evolutionary Theory

• Problem-solving theory: Dreams help process stressful or survival-related information.

• Dreams reflect daily concerns and allow for continuous information processing.

• Cross-cultural differences in dream content (e.g., Kurdish vs. Finnish children).

Neuroscience Theory

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

• Dream scenarios reflect emotional and motivational centers active during REM (limbic system), with less activation of the prefrontal cortex.

Psychoactive Drugs

Definition

Psychoactive drugs are substances that contain chemicals similar to those found naturally in the brain, altering neurotransmission and affecting emotions, perceptions, and behaviors. They can create dependence (physiological or psychological).

Stimulants

• Speed up activities of the nervous system, enhancing wakefulness and alertness.

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

• Cocaine: Small doses increase well-being and energy; large doses cause irritability and aggression; blocks dopamine reabsorption.

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

• ADHD treatment: Drugs like Adderall and Vyvanse increase dopamine, serotonin, and norepinephrine; in non-ADHD users, can cause euphoria and increased wakefulness.

• MDMA: Also a hallucinogen; increases serotonin release, heightens sensations, and social bonding; chronic use alters 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: Alter serotonin, perception, and neural communication; LSD can cause vivid hallucinations and distortions in time.

Marijuana (THC)

• Effects: Mix of excitatory, depressive, and hallucinatory.

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

• Memory impairment due to cannabinoid receptors in the hippocampus.

• Prolonged use: Impaired cognitive function (reversible), reduced dopaminergic function.

• Cannabis-induced psychosis: Hallucinations, delusions, disorganized thinking; linked to high THC content and family history.

• Today's cannabis is much stronger than in the 1970s (10x more THC).

Depressants

• Reduce arousal and stimulation; decrease neurotransmission and electrical activity.

• Includes alcohol, opioids, benzodiazepines, barbiturates.

• Used to treat anxiety, panic, and sleep disorders.

Alcohol

• Most commonly used depressant.

• Stimulating at low doses (via dopamine), depressant effects at higher doses.

• Lowers inhibition, impairs judgment, magnifies emotions.

• Females experience stronger effects (higher BAC for same weight).

Balanced-Placebo Design

• Expectations influence social behavior more than physiological effects.

• Placebo drinkers behave similarly to alcohol drinkers.

Your Brain on Alcohol

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

Depressants: Sedatives

• Barbiturates: Induce sleep or relaxation; psychologically and physically addictive; deadly with alcohol.

• Benzodiazepines: Treat anxiety and panic; highly addictive; excessive use leads to tolerance and memory impairment; deadly with alcohol.

Quaaludes

• Methaqualone (Quaaludes): CNS depressant, sedative, and hypnotic (increases GABA).

• Popular in 1970s; banned due to recreational abuse.

Opioids

• Derived from poppy seeds; act on brain's opioid receptors.

• Produce euphoria and pleasure; highly addictive.

• Prescription drugs (oxycodone, morphine, fentanyl) and illegal drugs.

• Slows brain activity and respiration; overdose risk.

Sleep Paralysis and Cultural Influences

Sleep Paralysis

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

• Feeling of being conscious but unable to move; often accompanied by anxiety, terror, and hallucinations (intruder, vestibular-motor, chest pressure).

• Culture influences the content and interpretation of sleep paralysis (e.g., "Old hag" in Newfoundland, "Kanashibari" in Japan, "Top-hat man" in recent years, "Pandafeche" in Italy).