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. It includes both waking consciousness and altered states of consciousness.

• Waking consciousness: Normal awareness of self and environment.

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

Sleep

Circadian Rhythm

The circadian rhythm is a biological rhythm that occurs over a 24-hour cycle, regulating sleep, hunger, concentration, and other physiological processes.

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

• SCN synchronizes with the external environment using light information from the retina.

• 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:

• Melatonin

• Follicle stimulating hormone

• Luteinizing hormone

• Growth hormone

Stages of Sleep

Sleep occurs in 5 stages, cycling every 90 minutes:

• Stages 1-4: NREM (Non-Rapid Eye Movement) Sleep

  • No eye movements, fewer dreams.

• Stage 5: 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 resemble photographs.

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 movements; brain waves similar to wakefulness.

• Antonia (muscle paralysis); only eyes and inner ear muscles move.

• REM rebound: increased REM after deprivation.

• Considered essential for health.

Hypnagogic State: Pre-Sleep Consciousness

• Occurs as one transitions into sleep.

• Features hypnagogic imagery (visual, somatic, auditory).

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

Sleep Paralysis

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

• Person is conscious but unable to move.

• Often accompanied by anxiety, terror, and hallucinations (intruder, vestibular-motor, 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).

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 & Displacement

• Sleep deprivation: Degeneration of neurons, ADHD-like symptoms, increased risk of illness and substance abuse, cognitive impairment similar to BAC of 0.07.

• Sleep displacement: Prevented from sleeping at normal time (e.g., jet lag, caffeine before bed).

Disruptions of Normal Sleep

• Jet lag: Mismatch between internal circadian cycles and environment.

• Rotating shift work: Alters circadian rhythm, leading to exhaustion, agitation, depression, and anxiety. Shift work can age the brain by over 6 years, but effects are reversible (~5 years).

• Daylight savings time: Associated with increased car accidents due to sleep disruption.

Sleep Deprivation & Mental Health

• Increased stress, emotional overreaction, and impaired emotional regulation (amygdala activation without frontal cortex regulation).

• Extreme cases (e.g., Peter Tripp's 200-hour wakeathon) can cause hallucinations, paranoia, and personality changes.

Sleep Hygiene

• Maintain regular sleep-wake schedule.

• Quiet sleep environment.

• Avoid caffeine after lunch and stimulating activities before bed.

• Use 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%).

• Risk factors: ADHD, depression, 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 during sleep and irrational beliefs.

Night Terrors & Sleep Apnea

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

• Sleep apnea: Blockage of airway during sleep, can lead to serious health risks (e.g., SIDS).

Narcolepsy

• Rapid, 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 asleep, vague awareness, 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.

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

Evolutionary Theory

• Problem-solving theory: Dreams help process stressful or threatening events, reconsider and reprocess critical information for survival.

• Example: Kurdish children had more intense, threatening dreams than Finnish children, reflecting daily life 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; less activation of prefrontal cortex.

Psychoactive Drugs

Definition

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

Stimulants

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

• Most common: Caffeine (blocks adenosine, which normally slows brain activity).

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

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

• ADHD Medications: (e.g., Adderall, Vyvanse) increase dopamine, serotonin, norepinephrine. In non-ADHD users, can cause euphoria and increased wakefulness.

• MDMA (Ecstasy): Both stimulant and hallucinogen; increases serotonin, heightens sensations, increases social bonding, but can lower mood post-use and alter brain structure with chronic 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 & LSD: Work on serotonin, alter perception, increase empathy, and can produce vivid hallucinations and altered sensory perception.

Marijuana (THC: Tetrahydrocannabinol)

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

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

• Impaired memory and "spaced out" feeling due to cannabinoid receptors in the hippocampus.

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

• High THC content, early use, and family history increase risk of cannabis-induced psychosis (hallucinations, delusions, disorganized thinking).

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

Depressants

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

• Includes alcohol, opioids, benzodiazepines, barbiturates, and Quaaludes.

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

Alcohol

• Most commonly used depressant.

• Stimulating at low doses (via dopamine), depressant effects at higher doses (0.05-0.10 BAC).

• Lowers inhibition, impairs judgment, magnifies emotions.

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

• Balanced-placebo design: Expectations can influence social behavior more than 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; 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): CNS depressant, sedative, and hypnotic (increases GABA); banned due to high abuse potential.

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.

*Additional info: The notes cover core concepts from Chapter 5 (Consciousness) and integrate material relevant to psychological disorders, biological psychology, and health/stress as they relate to sleep and drug use.*