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.

Circadian Rhythms and Sleep Regulation

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 sets itself with light information received from the retina, allowing synchronization with the outside world.

What is Sleep?

• Characterized by low physical activity and reduced sense of awareness.

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

Stages of Sleep

Overview

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

• Stages 1-4 are NREM (Non-Rapid Eye Movement) sleep: no eye movements, fewer dreams.

• Stage 5 is REM (Rapid Eye Movement) sleep: vivid dreams, quick 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.

• First stage of deep sleep; 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 similar to wakefulness.

• Atonia: body is paralyzed, but brain is active (paradoxical sleep).

• REM rebound occurs after deprivation; REM sleep is probably essential.

Hypnagogic State

• Pre-sleep consciousness with hypnagogic imagery (visual, somatic, auditory).

• May experience myoclonic/hypnic jerk (sudden muscle contractions).

Why Do We Sleep?

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

• Restorative (Restore & Repair Hypothesis): Sleep restores and replenishes us, aids memory consolidation, learning, and cognitive function (especially slow-wave sleep).

• Essential for growth and brain development, but the full reason is still not completely understood.

Sleep Deprivation and Displacement

Sleep Deprivation

• Degeneration of neurons in the brainstem; can mimic ADHD 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 prevented from sleeping at the normal time (e.g., jet lag).

• Consuming caffeine before bedtime can delay the internal clock.

Disruptions of Normal Sleep

• Jet lag: Symptoms from mismatch between internal circadian cycles and environment (fatigue, sluggishness, 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 the biological clock with the external environment.

Effects of Shift Work

• Shift work can age the brain by more than 6 years and cause a substantial decline in brain function.

• Lower scores for memory, processing speed, and overall brain power; reversible after ~5 years.

Daylight Savings Time

• Associated with increased car accidents due to sleep disruption.

Sleep Deprivation and Mental Health

• Increased stress, emotional overreaction, and lack of emotional regulation.

• Biological basis: amygdala activation without frontal cortex regulation leads to reacting to neutral images as if they were emotional.

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 and a quiet sleep environment.

• Avoid caffeine after lunch and stimulating activities before bed.

• Use the bed only for sleep; do not stay in bed 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), but 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 indicative of arousal during sleep.

Night Terrors & Sleep Apnea

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

Other Sleep Disorders

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

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

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).

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

Dreams: Function and Meaning

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 represent unconscious desires).

Evolutionary Theory

• Problem-solving theory: Dreams help process stressful events and daily concerns, 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 dreamer's fears, emotions, and concerns; motivational and emotional centers (limbic system) are active during REM, with less activation of the prefrontal cortex.

Psychoactive Drugs

Definition and Effects

• Substances containing chemicals similar to those found naturally in the brain, altering neurotransmission.

• Influence emotions, perceptions, and behaviors; can create physiological or psychological dependence.

Stimulants

• Speed up nervous system activity, enhancing wakefulness and alertness (arousal effect on CNS).

• Most commonly used: caffeine (blocks adenosine, which normally slows brain activity).

• Other examples: cocaine (blocks dopamine reuptake), amphetamines (stimulate dopamine release), MDMA (also a hallucinogen, increases serotonin release).

Cocaine

• Small doses: increased well-being, energy, confidence; large doses: anger, violence, irritability.

• "Highs" due to dopamine flooding the brain.

Amphetamines

• Strong stimulants (e.g., Dexedrine, Benzedrine, methamphetamine).

• Chronic use can cause neurological and physical problems, changes to brain structure.

Amphetamines & ADHD

• ADHD associated with lower dopamine levels; drugs like Adderall increase dopamine, serotonin, norepinephrine.

• Non-ADHD users may experience euphoria and increased wakefulness.

MDMA (Ecstasy)

• Originally a blood-clotting agent; now used recreationally for emotional and sensual effects.

• Massive serotonin release, heightened sensations, increased social bonding.

• Chronic use can alter brain structure and lower mood post-use.

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 and LSD alter serotonin and perception; LSD can cause vivid hallucinations and increased neural communication.

Marijuana (THC)

• Effects are a mix of excitatory, depressive, and mildly hallucinatory.

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

• Memory impairment due to cannabinoid receptors in the hippocampus.

• Prolonged use can impair cognitive function (reversible) and reduce dopaminergic function.

• High THC content increases risk of cannabis-induced psychosis (hallucinations, delusions, disorganized thinking).

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

Depressants

• Reduce arousal and stimulation ("downers"); decrease neurotransmission and electrical activity.

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

Alcohol

• Most commonly used depressant; stimulating at low doses (via dopamine), depressant at higher doses.

• Lowers inhibition, impairs judgment, magnifies emotions.

• Females experience effects more heavily due to higher BAC at same weight.

Balanced-Placebo Design

• Expectations influence social behavior more than physiological effects.

• Placebo drinkers behave similarly to alcohol drinkers in social contexts.

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, euphoria
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; can be deadly with alcohol.

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

Quaaludes

• Methaqualone (brand name Quaaludes); CNS depressant, sedative, and hypnotic (increases GABA).

• Popular in the 1970s; banned due to widespread recreational use.

Opioids

• Derived from poppy seeds; act on brain's opioid receptors to produce 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 is used to avoid withdrawal rather than to feel good.

Summary Table: Sleep Stages

Stage	Key Features	Brain Waves
Stage 1	Transition from wakefulness, light sleep, hypnagogic imagery	Theta
Stage 2	Sleep spindles, K-complexes, light sleep	Theta with spindles/K-complexes
Stage 3	Deep sleep, difficult to awaken	Delta
Stage 4	Deepest sleep, growth hormone release	Delta
REM	Vivid dreams, muscle atonia, rapid eye movements	Similar to wakefulness (beta)

Additional info: This guide expands on the provided slides with definitions, examples, and context for key psychological concepts related to consciousness, sleep, dreams, and psychoactive drugs.