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Consciousness Lecture 3 — Video Notes (Sleep, Dreams, Drugs & Effects)

Consciousness: Definitions and Core Concepts

  • Consciousness can be defined as: "our awareness of ourselves and our environment."
    • Source: Page 3 summary
  • Altered Consciousness includes states that are:
    • Spontaneously occurring: Daydreaming, Drowsiness, Dreaming
    • Physiologically induced: Food or oxygen deprivation leading to altered states
    • Psychologically induced: Sensory deprivation, Hypnosis, Meditation
    • Also includes experiences like hallucinations and orgasm (as listed in the transcript)
  • Conscious vs. Unconscious Activity: The Dual-Track Mind
    • Unconscious (low) track: automatic actions performed without conscious awareness
    • Conscious (high) track: deliberate actions we know we are doing
    • Automatic processing vs. conscious control example:
    • Conscious high track says, “I saw a bird!”
    • Unconsciously, we perceive color, motion, form, and depth
  • Example of Dual Processing: Sensation and Perception
  • Stroop Task: Demonstration of conscious vs. unconscious processing
    • Task: Say aloud the COLOR of the word, not the word itself
    • Examples and expected responses:
    • Word: RED printed in color RED → Correct response: Red
    • Word: RED printed in color GREEN → Correct response: Green
    • Word: PURPLE printed in color BLUE → Correct response: Blue
  • Parallel vs. Sequential Processing
    • Parallel processing: Processing multiple aspects of a stimulus/problem simultaneously
    • Sequential processing: Processing one aspect at a time
    • Paralell processing is efficient for familiar tasks; sequential processing used for new or difficult problems
  • Evidence for the Dual-Track Mind
    • Subliminal priming: processing stimuli not consciously perceived but influencing responses
    • Blindsight: residual visual processing in the absence of conscious visual perception
    • Supports the idea of separate visual perception (high road) and visual action (low road) tracks
  • Video References (demonstrations):
    • Hollow mask illusion video exploring high vs low road: https://www.youtube.com/watch?v=OHuStlT1RM8
    • “Count the number of times players in white shirts pass” video: http://www.youtube.com/watch?v=vJG698U2Mvo
    • Change blindness video: https://www.youtube.com/watch?v=v3iPrBrGSJM
  • Selective Attention
    • Definition: Focusing conscious awareness on a particular stimulus
    • Forms:
    • Inattentional blindness
    • Change blindness
  • Change Blindness illustration
    • Notable finding: Two-thirds of people didn’t notice when the person giving directions was replaced by a similar-looking person
    • The Switch example noted in the transcript
  • Quick Quiz Reference (MCQ 1):
    • Danae can talk on the phone, answer an email, and gesture to a colleague all at the same time. Which skill has Danae mastered?
    • Correct: Parallel processing

Sleep and Dreams

  • Activity: Sleep IQ Test (True/False) – overview of sleep concepts via True/False statements (11–12 items listed in transcript)
  • Sleep and Dreams: Biological rhythms and the purpose of sleep
  • Why we sleep and what we dream about
    • Sleep timing is influenced by light exposure; the suprachiasmatic nucleus (SCN) regulates melatonin production
  • Sleep Stages and Sleep Cycles: What is Measured
    • Measurements include:
    • Left and right eye movements
    • EMG (muscle tension)
    • EEG (brain waves)
  • Sleep Stages and Cycles
    • Four sleep stages: N1, N2, N3 (Deep sleep), REM (Dreaming)
    • Sleep cycles: progression through all sleep stages across the night; cycles repeat
  • Sleep Stages (part 1)
    • N1: Slow breathing and irregular brain waves
    • N2: More relaxed state
    • N3: Deep sleep; sleep spindles occur
    • REM: Dreaming occurs
  • Brain Waves and Sleep Stages
    • Wakeful beta waves vs relaxed alpha waves vs deep N3 delta waves
    • REM sleep waves resemble N1 (rapid eye movement) but body is internally aroused more than during NREM
  • Not yet asleep: Beta and Alpha waves (wakeful patterns transitioning into sleep)
  • Sleep Stages (part 2): Non-REM stages
    • N1: transition to sleep; slow pulse and breathing; irregular brain waves
    • N2: deeper relaxation; sleep spindles occur
    • N3: deep sleep (slow-wave sleep)
  • Sleep Stages: REM Sleep
    • Discovery: Aserinsky (1953) identified REM sleep with dreaming and rapid eye movements
    • REM characteristics: heart rate rises, breathing becomes rapid; sleep paralysis; genital arousal
  • Video: REM Sleep in Action (link provided in transcript)
  • 90 Minute Cycles and Sleep Duration
    • Across an 8-hour sleep period, REM duration increases the longer you sleep
    • With age: more awakenings and less deep sleep
  • Sleep Stage: Paradoxical Sleep
    • Question: Which stage is known as paradoxical sleep? Answer: REM
  • Why Do We Sleep? Part 1
    • Sleep differences by: age, genetic variation, culture
    • Light exposure regulates sleep; role of SCN and melatonin
  • Why Do We Sleep? Part 2
    • Functions of sleep: Protects, restores and repairs, strengthens memories, facilitates creative problem solving, supports growth hormone activity
  • Dreams
    • Dreams: the stream of images, actions, and feelings experienced during REM sleep
    • What we dream about:
    • Negative events or emotions (often related to failure)
    • Dreams do not often involve sexuality
    • Dreams incorporate real-world sounds and stimuli
    • Dreams reflect images from recent or frequent experiences
  • Why Do We Dream? Theoretical explanations
    • Wish fulfillment (Freud): Dreams express unacceptable feelings; contain manifest content and latent content
    • Information-processing: Dreams help sort/day’s events and consolidate memories
    • Physiological function: Dreams help develop and preserve neural pathways; REM triggers random visual memories woven into stories
    • Activation-synthesis: Dreams reflect brain’s attempt to synthesize random neural activity into stories
    • Cognitive-development theory: Dreams reflect dreamer’s knowledge and understanding
    • Open questions/criticisms: No definitive scientific consensus; dream interpretation can be subjective; neuroscience of dreaming remains incomplete

Consciousness: Sleep and Dreams – Open Questions and Connections

  • Sleep is linked to memory consolidation and creative problem solving; REM and non-REM play different roles in processing memories
  • Dreams may reflect ongoing cognitive development and emotional processing, but content interpretation varies across individuals

Drugs and Their Effects: Overview

  • The Brain and Consciousness intersects with Sleep and Dreams in terms of how psychoactive substances alter perception, mood, and awareness
  • Tolerance and Addiction: core concepts in psychoactive drug effects
  • Types of Psychoactive Drugs: broad categories include depressants, stimulants, hallucinogens, cannabis, and opioids

Substance Use Disorders and Addiction

  • Today’s psychiatric framework defines substance use disorders with multiple criteria rather than a single symptom
  • Psychoactive drug: a natural or synthetic chemical substance that alters brain function, causing changes in perceptions, thoughts, moods, and behaviors
  • Substance use disorder: a disorder characterized by continued substance use despite significant life disruption
  • Diagnostic thresholds involve patterns of use, control, social functioning, hazardous use, and physiological adaptations
  • When is Drug Use a Disorder? Diminished Control, Diminished Social Functioning, Hazardous Use, Drug Action
    • Diminished Control: uses more substance, longer than intended; difficulty regulating use; time spent obtaining/using; cravings
    • Diminished Social Functioning: work/school/home commitments disrupted; social activities reduced
    • Hazardous Use: continued use despite physical/psychological problems
    • Drug Action: tolerance and withdrawal symptoms on cessation

Tolerance, Addiction, and Withdrawal

  • Tolerance: repeated use leads to a need for larger doses to achieve the same effect
  • Addiction: compulsive craving despite harmful consequences
  • Withdrawal: unpleasant physical/mental effects when stopping

Types of Psychoactive Drugs

  • Depressants
    • Examples: Alcohol, Barbiturates, Opioids, Cannabis
    • General effect: depress neural activity and slow body functions; alcohol acts as a disinhibitor
  • Stimulants
    • Examples: Nicotine, Caffeine, Cocaine, Methamphetamine
    • General effect: excite neural activity and speed up body functions; often increase energy and alertness; can be highly addictive
  • Hallucinogens
    • Examples: LSD, MDMA (Ecstasy), Psilocybin, Ketamine, Ayahuasca
    • Effects: distort perceptions and evoke sensory images in absence of external input
  • Opioids
    • Examples: Opium derivatives (morphine, heroin), fentanyl, oxycodone, hydrocodone
    • Effects: depress neural activity, relieve pain and anxiety; extremely addictive
  • Cannabis
    • Active compound: THC (delta-9-tetrahydrocannabinol)
    • Effects: increases sensitivity to colors/sounds, relaxes, impairs motor and perceptual skills, slows reaction time; lingers in the body
    • Research notes (NAS/2023 updates):
    • Alleviates some kinds of pain and nausea; may help sleep temporarily
    • Does not necessarily increase tobacco-related disease risk; but predicts higher risk of traffic accidents and psychosis, anxiety, suicidal thoughts; may impair attention, learning, memory; potential impact on academic achievement

Alcohol: Details and Statistics

  • What is a Standard Drink?
    • One standard drink = 0.6\,\text{oz of ethanol (ethyl alcohol)}
    • Beer typically contains 3–9% alcohol; not required to reveal exact % on label; average around 5% commonly assumed for calculations
    • One drink = 12\,\text{oz beer}
  • Alcohol Use Statistics (2019 NCHS data, young adults 18–25):
    • 54.3% drink alcohol
    • 34.3% binge drank (5+ drinks in one outing) in the past month
    • 8.4% are heavy drinkers (5+ drinks on 5+ days in the past 30 days)
    • 9.3% have an alcohol use disorder
  • Long Island Iced Tea composition (example):
    • \text{Long Island Iced Tea} = 2.2\ \text{standard drinks} = \tfrac{1}{2}\text{ oz triple sec} + \tfrac{1}{2}\text{ oz light rum} + \tfrac{1}{2}\text{ oz gin} + \tfrac{1}{2}\text{ oz vodka} + \tfrac{1}{2}\text{ oz tequila} + 1\text{ oz sour mix} + \text{ cola}
  • Recommended Daily Alcohol Limits:
    • Men: Not more than 2 per day (and not every day)
    • Women: Not more than 1 per day (and not every day)
    • Most longer-term risks increase around 3 drinks/day
  • Depressants: Alcohol as a disinhibitor
  • Consequences of Alcohol Use
    • Slowed neural processing: slower sympathetic activity; slurred speech; slower reaction times
    • Memory disruption: impaired memory formation; possible long-term effects on synaptic growth; blackouts
    • Reduced self-awareness: lower inhibitions; increased risk-taking or unconscious behavior
  • Alcohol Use Disorder (AUD)
    • Contributes to more than 200 diseases; potential brain shrinkage and premature death
  • MC Review (MC3): Which is NOT a potential consequence of alcohol use? Options include lowered inhibitions, increased heart rate, zoning out, slower reaction times, memory impairment

Barbiturates

  • Barbiturates (tranquilizers, including some sleeping pills)
    • Depress CNS activity; reduce anxiety but impair memory and judgment
    • Suppress REM sleep
    • Potentially lethal when combined with alcohol
    • Examples: Nembutal, Seconal, Amytal

Stimulants

  • Nicotine
    • Highly addictive psychoactive drug in tobacco
    • Stimulates CNS to release a flood of neurotransmitters; diminishes appetite; boosts alertness and mental efficiency; calms anxiety; reduces pain sensitivity
    • Produces strong acute cravings and withdrawal symptoms leading to relapse
  • Cocaine
    • Can be snorted, injected, or smoked
    • Powerfully stimulates brain reward pathways; rapid euphoria and heightened arousal followed by a crash
    • Can cause emotional disturbances and agitated depression as neurotransmitter levels drop within 15–30 minutes
    • Mechanism (cocaine euphoria/crash):
    • Cocaine blocks reuptake of dopamine, norepinephrine, and serotonin, intensifying their effects in the synapse
    • When levels fall, a crash occurs
    • Conceptual diagram elements (synaptic process):
    • Normal: reuptake of neurotransmitters from synapse back into sending neuron
    • Cocaine presence: blockade of reuptake increases neurotransmitter presence in synapse
  • Methamphetamine
    • Powerfully addictive; stimulates CNS; increases energy and mood
    • Over time, reduces baseline dopamine levels

Hallucinogens

  • Hallucinogens induce psychedelic experiences and distort perception
  • Examples: LSD, MDMA (Ecstasy), psilocybin, ketamine, ayahuasca
  • Effects: vivid imagery, altered sensory perception, and sometimes spiritual or introspective experiences

Opioids

  • Opioids includes opium derivatives (morphine, heroin), and synthetic substitutes (methadone, fentanyl)
  • Effects: depress neural activity, relieve pain and anxiety; high risk of addiction and fatal overdose

Cannabis

  • Active compound: THC (delta-9-tetrahydrocannabinol)
  • Effects: increases sensitivity to colors, sounds, tastes, and smells; can relax and disinhibit, but may impair motor and perceptual skills and reaction time
  • Duration: lingers in the body; impairment of motor coordination, attention, learning, and memory; can affect driving and safety
  • Research notes (NAS/2023):
    • May alleviate chronic pain, chemotherapy-related nausea, and MS-related muscle soreness
    • May improve short-term sleep in some cases
    • Does not clearly increase risk for some tobacco-related diseases but is linked to higher risk of traffic accidents and potential association with psychosis, social anxiety, and suicidal thoughts; possible impairment in attention, learning, memory, and academic performance

Key Concepts, Formulas, and Numerics to Remember

  • Standard drink and ethanol content
    • 1\ \text{standard drink} = 0.6\ \text{oz of ethanol (ethyl alcohol)}
    • 1\ \text{drink} = 12\ \text{oz beer}
    • Beer % range: roughly 3\% - 9\%, commonly approximated as 5\% for calculations
  • Alcohol proportions in mixed drinks (example)
    • Long Island Iced Tea: \text{LIIT} = 2.2\ \text{standard drinks} = \tfrac{1}{2}\text{ oz triple sec} + \tfrac{1}{2}\text{ oz light rum} + \tfrac{1}{2}\text{ oz gin} + \tfrac{1}{2}\text{ oz vodka} + \tfrac{1}{2}\text{ oz tequila} + 1\text{ oz sour mix} + \text{ cola}
  • Sleep cycle timing
    • Typical human sleep consists of cycles every \approx 90\text{ minutes}, with REM increasing as the night progresses and age-related changes increasing awakenings and reducing deep sleep
  • REM sleep characteristics
    • REM is also called paradoxical sleep due to brain activity similar to wakefulness while the body experiences atonia (sleep paralysis) and autonomic arousal
  • Dream theories (summary):
    • Freud’s wish fulfillment: manifest content vs latent content
    • Information-processing: consolidating day’s memories
    • Physiological function: neural pathway maintenance during REM
    • Activation-synthesis: random neural activity interpreted by the brain to form dreams
    • Cognitive-development: dreams reflect developmental knowledge and thinking
  • Sleep functions (summary):
    • Protection, restoration, memory consolidation, problem-solving facilitation, growth hormone activity
  • Major sleep-stage identifiers (quick reference):
    • N1: light sleep, slow breathing
    • N2: relaxed, sleep spindles
    • N3: deep sleep, delta activity
    • REM: rapid eye movements, dreaming, heightened autonomic activity

Connections and Practical Implications

  • Dual-Track Mind implications for everyday tasks: multitasking can rely on parallel processing for familiar tasks but may require sequential processing for learning new skills
  • Attention and perception: selective attention can lead to inattentional or change blindness, impacting everyday tasks like driving or monitoring information streams
  • Sleep’s practical relevance: adequate sleep supports learning, memory consolidation, and creative problem solving; sleep deprivation impairs attention and decision-making
  • Drugs and health: understanding tolerance, withdrawal, and differences among drug classes informs health education, prevention, and treatment approaches

Open Questions and Critical Reflections

  • Dream content and meaning: while theories offer explanations, there is no single consensus; interpretation remains subjective and influenced by current neuroscience
  • The neuroscience of sleep: ongoing research into the exact roles of REM and NREM in memory consolidation and emotional regulation
  • Substance use guidelines: cultural and individual variation in sleep/wake cycles and alcohol tolerance; public health recommendations emphasize moderation and awareness of risks

Quick Reference (Key Takeaways)

  • Consciousness involves both automatic and deliberate processing; the brain uses parallel and sequential strategies depending on familiarity and difficulty
  • Sleep occurs in 4 stages (N1, N2, N3, REM) and cycles roughly every 90 minutes; REM is associated with dreaming and physiological arousal
  • Dreams can be interpreted through multiple theoretical lenses; there is no single, universally accepted explanation
  • Psychoactive drugs alter perception, mood, and behavior through various mechanisms; tolerance and withdrawal contribute to ongoing use; substance use disorders involve multiple diagnostic criteria
  • Alcohol has well-defined standard drink metrics and clear health risks, with widely used public health limits to reduce long-term harm

End of notes