topic 5. 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: Includes sleep paralysis, locked-in syndrome, out-of-body experiences, near-death experiences, mystical experiences, hypnosis, meditation, and effects of psychoactive drugs.

Sleep

What is Sleep?

Sleep is a state characterized by low physical activity and reduced awareness. It is associated with the secretion of several hormones:

• Melatonin

• Follicle stimulating hormone

• Luteinizing hormone

• Growth hormone

Circadian Rhythm

Circadian rhythms are biological cycles that occur over approximately 24 hours, regulating sleep, hunger, and other bodily functions.

• Regulated by the suprachiasmatic nucleus (SCN) in the hypothalamus.

• SCN synchronizes with light information from the retina.

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

Stages of Sleep

Sleep occurs in 5 stages, cycling every 90 minutes:

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

  • No eye movements, fewer dreams.

  • Stage 1: Transition from wakefulness (10-15 min), brain waves slow, dream-like images.

  • Stage 2: Further slowing, sleep spindles and K-complexes (may aid memory storage), ~65% of sleep, lasts ~20 min.

  • Stages 3 & 4: Deep sleep, delta waves, crucial for feeling rested, growth hormone production, more time spent by children, suppressed by alcohol, hardest to awaken in stage 4.

• Stage 5: REM (Rapid Eye Movement) Sleep

  • Vivid dreams, quick eye movements.

  • Brain waves similar to wakefulness.

  • Antonia (muscle paralysis), active brain, inactive body.

  • REM rebound: increased REM after deprivation.

Hypnagogic State

The hypnagogic state is the transitional phase between wakefulness and sleep, often accompanied by vivid imagery and myoclonic (hypnic) jerks.

• Imagery can be visual, somatic, or auditory.

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, aids memory consolidation, learning, and cognitive function, especially during slow-wave sleep.

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

Sleep Deprivation & Displacement

• Sleep deprivation: Degeneration of neurons, ADHD-like symptoms, increased risk of illness and substance abuse, emotional dysregulation.

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

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

Disruptions of Normal Sleep

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

• Rotating shift work: Alters circadian rhythm, causes exhaustion, agitation, sleep problems, depression, and anxiety. Bright light therapy can help realign biological clock.

• Shift work can age the brain by over 6 years, but effects are reversible (~5 years).

• Daylight savings time increases car accidents due to sleep disruption.

Sleep Deprivation & Mental Health

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

• Example: Peter Tripp's "wakeathon" led to hallucinations, paranoia, and personality changes.

Sleep Hygiene

• Regular sleep-wake schedule

• Quiet sleep environment

• Avoid caffeine after lunch

• Avoid 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% prevalence; higher in students (~25%)

• Associated with ADHD, depression, employment stress

• Treatment: psychotherapy, 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

• Brain activity shows arousal during sleep

• Irrational beliefs and excessive worry

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, unexpected onset of sleep, directly into REM

• 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 during stage 3 sleep; vague consciousness; safe to wake.

Dreams

Function & Meaning of Dreams

• Freud's Theory: Dreams as unconscious wish fulfillment; latent (hidden) vs. manifest (surface) content.

• Symbolic interpretation: objects in dreams may represent unconscious desires.

• Sexual dreams are less common than Freud proposed (~10%).

Evolutionary Theory

• Problem-solving theory: Dreams help process daily concerns and stressful events, aiding survival by allowing information to be reconsidered and reprocessed.

• Example: Kurdish children have more intense, threatening dreams than Finnish children.

Neuroscience Theory

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

• Dream content reflects emotional and motivational centers (limbic system) active during REM, with less prefrontal cortex involvement.

Psychoactive Drugs

Definition

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

Stimulants

Stimulants speed up nervous system activity, enhancing wakefulness and alertness.

• Caffeine: Most common stimulant; blocks adenosine, increasing alertness.

• Cocaine: Small doses increase well-being and energy; large doses 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; improve wakefulness and coping in ADHD.

• MDMA: Also a hallucinogen; increases serotonin, heightens sensations, increases social bonding; chronic use alters brain structure.

Hallucinogens (Psychedelics)

Hallucinogens produce perceptual changes and hallucinations.

• Examples: LSD, psilocybin, ayahuasca, marijuana, ecstasy, salvia.

• Therapeutic interest: mystical experiences, treatment-resistant conditions.

• MDMA & LSD: Alter serotonin, perception, and neural communication; LSD can cause vivid, sometimes terrifying hallucinations.

Marijuana (THC)

• Effects: Excitatory, depressive, and hallucinogenic; triggers spontaneous ideas, distorted perceptions, increased sensitivity to stimuli.

• Memory impairment due to cannabinoid receptors in hippocampus.

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

• Cannabis-induced psychosis: Hallucinations, delusions, disorganized thinking; risk factors include high THC, early use, family history.

• THC content in cannabis has increased over time (10x since 1970s).

Depressants

Depressants reduce arousal and stimulation by decreasing neurotransmission and electrical activity.

• Includes alcohol, opioids, benzodiazepines, barbiturates.

• Used to treat anxiety, panic, sleep disorders.

Alcohol

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

• Lowers inhibition, impairs judgment, magnifies emotions.

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

• Balanced-placebo design: Expectations 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

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, hypnotic (increases GABA).

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

Opioids

• Derived from poppy seeds; act on 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 used to avoid withdrawal rather than to feel good.

Sleep Paralysis & Culture

Sleep paralysis is a state of consciousness where one is awake but unable to move, often accompanied by anxiety, terror, and hallucinations. Cultural beliefs shape the experience:

• Old hag (Newfoundland, English speakers)

• Kanashibari (Japan, bound up with metal)

• Top-hat man (since late 2000s)

• Pandafeche (cat-like creature, Italians)