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.

Circadian Rhythms

Biological Clock and Regulation

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

• Suprachiasmatic nucleus (SCN): The brain's clock mechanism, located in the hypothalamus.

• SCN synchronizes with external light via retinal projections.

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

What is Sleep?

Characteristics and Hormonal Changes

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 Cycle and Brain Activity

Sleep occurs in 90-minute cycles, consisting of five stages. Stages 1-4 are NREM (non-rapid eye movement), and stage 5 is REM (rapid eye movement).

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

• REM (Stage 5): 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.

• Sleep spindles and K-complexes appear (may help maintain sleep and memory storage).

• Comprises up to 65% of total sleep; lasts ~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 movement; brain waves similar to wakefulness.

• Antonia (muscle paralysis).

• REM rebound: increased REM after deprivation.

• Essential for cognitive and emotional health.

Hypnagogic State

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

• Myoclonic/hypnic jerk: sudden muscle contractions.

Why Do We Sleep?

Adaptive and Restorative Functions

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

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

• Essential for growth and brain development.

Sleep Deprivation & Displacement

Effects and Risks

• Sleep deprivation: Degeneration of neurons in the brainstem, ADHD-like symptoms, increased risk of illness and substance abuse.

• Every hour of deprivation increases risk of physical and mental health problems.

• Effects similar to 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 and Shift Work

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

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

• Bright light can help realign biological clock.

Shift Work and Cognitive Decline

• 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.

Sleep Deprivation & Mental Health

Emotional and Biological Effects

• Increased stress and emotional reactivity.

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

Case Study: Peter Tripp

• Staged a 200-hour "wakeathon"; 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% prevalence; higher among 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; 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; risk of 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: Sleepwalking during stage 3 sleep; vague consciousness, safe to wake.

Dreams

Function and Meaning

Dreams are a universal aspect of sleep, with various theories explaining their function and meaning.

Freud's Theory

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

• Symbolic interpretation: objects and scenarios in dreams represent unconscious thoughts.

Evolutionary Theory

• Problem-solving theory: Dreams help process stressful or threatening information relevant to survival.

• 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 and Effects

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

• Speed up nervous system activity, 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 (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, social bonding, and can alter brain structure with chronic use.

Hallucinogens (Psychedelics)

• Produce hallucinations or changes in perception (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 hallucinogenic.

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

• Memory impairment due to cannabinoid receptors in hippocampus.

• Prolonged use can impair cognitive function (reversible) and reduce 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 higher than 1970s).

Depressants

• Reduce arousal and stimulation; decrease 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, depressant at higher doses.

• Lowers inhibition, impairs judgment, magnifies emotions.

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

• Balanced-placebo design shows expectations influence social behavior more than physiological effects.

Your Brain on Alcohol

BAC Range	Effects
0.01–0.05	Behavior and judgment slightly altered; 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 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).

• Highly addictive; surge of dopamine leads to intense pleasure.

• Cycle of addiction: drug 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 major public health concern, sometimes exceeding COVID-19 deaths in certain regions.

Additional info: These notes expand on brief points with definitions, examples, and context suitable for college-level psychology students, following a mini-textbook style.