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

Circadian Rhythm

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

• Regulation: Controlled by the suprachiasmatic nucleus (SCN) in the hypothalamus, which synchronizes with light information from the retina.

• Functions: Influences sleep-wake cycle, body temperature, hormone production, and blood pressure.

What is Sleep?

Sleep is 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

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 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 about 65% of total sleep; lasts around 20 minutes.

Stages 3 and 4: Deep Sleep

• Delta waves dominate.

• Crucial for feeling rested.

• Growth hormone production increases.

• Children spend more time in these stages than elderly.

• Suppressed by alcohol.

• Stage 4 is hardest to awaken from.

Stage 5: REM Sleep

• Rapid eye movements; brain waves similar to wakefulness.

• Antonia (muscle paralysis).

• REM rebound: increased REM after deprivation.

• Essential for cognitive function.

Hypnagogic State

The hypnagogic state is the transitional phase between wakefulness and sleep, characterized by vivid imagery:

• Visual, somatic, and auditory hypnagogic imagery

• Myoclonic/hypnic jerk: Sudden muscle contractions.

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 the body, consolidates memory, and supports learning and cognitive function (especially slow-wave sleep).

• Essential: Necessary for growth and brain development, though the full reason is still unknown.

Sleep Deprivation & Displacement

• Sleep deprivation: Degeneration of neurons, ADHD-like symptoms, increased risk of illness and substance abuse. Effects comparable to a blood alcohol concentration (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, sleep problems, depression, and anxiety.

• Bright light therapy: Can help realign biological clock.

Effects of Shift Work

• Shift work can age the brain by more than 6 years.

• Decline in 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, especially after the spring shift.

Sleep Deprivation & Mental Health

• Increased stress and emotional reactivity.

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

Extreme Case: Peter Tripp

• Stayed awake for 200 hours, leading to incoherent speech, hallucinations, paranoia, and personality changes.

• Died at 73 of a stroke.

Sleep Hygiene for Students

• Maintain regular sleep-wake schedule.

• Quiet sleep environment.

• Avoid caffeine after lunch and stimulating activities before bed.

• Use bed only for sleep.

Sleep Disorders

Insomnia

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

• 9-20% prevalence; higher among students (~25%).

• Associated with ADHD, depression, employment issues.

• 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 arousal 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.

Narcolepsy

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

• Cataplexy (sudden muscle weakness).

• Associated with lack of orexin.

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

• Unconscious wish fulfillment: Dreams express latent (hidden) desires through manifest (surface) content.

• Symbolic interpretation: Objects in dreams may represent unconscious thoughts or desires.

Evolutionary Theory

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

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

• Kurdish vs. Finnish children study: Kurdish children had more intense, threatening dreams.

Neuroscience Theory

• Activation-synthesis theory: Dreams result from 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 are substances that 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

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

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

• Cocaine: Small doses increase well-being; large doses cause irritability and violence. Blocks dopamine reabsorption.

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

• ADHD medications: Adderall, Vyvanse increase dopamine, serotonin, norepinephrine; improve wakefulness and coping with stress.

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

Marijuana (THC)

• Effects are excitatory, depressive, and mildly hallucinatory.

• 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; risks include high THC content, early use, family history.

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

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 commonly used depressant.

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

• Lowers inhibition, impairs judgment, magnifies emotions.

• Females experience effects more heavily (same weight, higher BAC).

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; dopamine release, euphoria, relaxation.
0.03-0.12	Blurred vision, slurred speech, impaired coordination, increased risk-taking.
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: CNS depressant, sedative, and hypnotic (increases GABA).

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

Opioids

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

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

• Slows brain activity, depresses respiration; highly addictive due to dopamine surge.

• Cycle of addiction: Used to avoid withdrawal rather than to feel good.

Three Waves of Opioid Overdose Deaths

Wave	Description
1	Prescription opioid overdose
2	Heroin overdose
3	Synthetic opioid overdose (e.g., fentanyl)

Overdose vs. COVID-19 Deaths (2020)

Opioid overdose deaths have become a significant public health concern, with rates comparable to or exceeding COVID-19 deaths in some regions.