Consciousness and Sleep PDF

Consciousness Awareness What is Consciousness? Consciousness: The awareness of internal and external stimuli Our subjective awareness of ourselves and our environment! What is Consciousness? Subjective and private Others cannot know our reality Dynamic Always changing Self-...

Consciousness Awareness What is Consciousness? Consciousness: The awareness of internal and external stimuli Our subjective awareness of ourselves and our environment! What is Consciousness? Subjective and private Others cannot know our reality Dynamic Always changing Self-reflective Our mind is aware of its own consciousness Measuring Consciousness Need an operational definition... Self-reports Cannot verify Physiological study (e.g., EEG) Cannot indicate experience subjectively Behavioural study (e.g., rouge test) Need to infer state of mind Testing for Consciousness Rouge test Do you recognize yourself in the mirror? How?  The Psychodynamic View Conscious Preconscious Unconscious Mental events we Events outside of Not brought into are currently aware current awareness; conscious awareness of easily recalled (usually)  The Cognitive View Controlled Automatic Voluntary Minimal use of conscious attention processing Slow but Fast but flexible static Divided Attention Adaptive but has limits! Difficult if tasks require similar resources e.g., listening to lecture and reading a text Impacts other actions e.g., using cell phone & driving The Science of Sleep Circadian Rhythms Rhythmic daily cycles (wakefulness → sleep) Sleep Regulation Sleep regulated by specific part of the hypothalamus: suprachiasmatic nucleus (SCN) SCN signals the pineal gland to release melatonin The hormone melatonin is important for the regulation of peoples’ biological clock. Sleep Regulation People require 7–10 hrs of sleep daily Genetic mutation in DEC2 makes a person need less sleep! Sleep deprivation involves missing required amount of restful sleep over one or more days Accumulated sleep loss over multiple days is known as sleep debt Stages of Sleep Stage 1: Light sleep (1-10 mins) Alpha/beta waves from wakefulness transition to theta waves when you have fallen asleep Hypnic/myoclonic jerks & hypnagogic imagery Stages of Sleep Stage 2: Deeper sleep (10-25 mins) Brain waves decelerate, heart rate slows, body temp. decreases, muscles relax, and eye movements cease Sleep spindles (1-2 second bursts of rapid brain activity) Stages of Sleep Stage 3 & 4: Deeper sleep (after 10-30 mins) Appearance of delta waves Called “slow-wave” sleep Important to feeling ‘rested’ Stages of Sleep Stage 5: a.k.a. REM sleep Rapid eye movement (REM) Occupies 20-25% of our night’s sleep! Cycles of REM sleep last between 20min-1h Stages of Sleep Sleep cycle changes throughout the night: Stage 4 & Stage 3 no longer occur REM periods become longer Sleep Disorders Insomnia Chronic difficulty in falling asleep, staying asleep, or experiencing restful sleep The most common sleep disorder (10-40% of population) Sleep Disorders Narcolepsy Experience episodes of sudden sleep Immediately enter REM sleep Sometimes has associated cataplexy – a complete loss of muscle tone during waking hours Can be caused by genetic factors, specific types of brain damage, or lack of orexin Sleep Disorders Sleep Apnea Blockage of airway interrupts sleep Rouses person from deeper levels of sleep Can occur 100s or 1000s of times per night! Sleep Disorders Night Terrors Sudden waking episodes characterized by screaming, perspiring, and confusion, followed by a return to deep sleep Episodes last only a few minutes! Sleep Disorders Sleepwalking Episodes where a person walks while asleep Between 15-30% of children and 4-5% of adults sleepwalk occasionally People deprived of sleep are more likely to exhibit sleepwalking when they do fall asleep  Dreaming Dreaming is a near universal experience Even blind people dream! Some constants across cultures in dream content Why do we dream? Dreams help us process emotional memories? Dreams allow us to learn new strategies or ways of doing things? Freud’s Dream Protection Theory Described dreams as the ‘guardians of sleep’ During sleep, the ego (a sort of mental censor) is less able to keep sexual and aggressive instincts at bay by repressing them Freud’s Dream Protection Theory The dream-work disguises and contains the pesky sexual and aggressive impulses by transforming them into symbols that represent wish fulfillment – how we wish things could be Activation-Synthesis Theory Proposes that dreams reflect brain activation in sleep, rather than a repressed unconscious wish Balance of neurotransmitters (primarily acetylcholine, serotonin, and norepinephrine) in the brain shifts continually  Activation-Synthesis Theory Shifts in neurotransmitter concentrations during the night activate/depress different brain areas Chaotic pattern of neural firing Translated by forebrain as effectively as possible (can cause strange and disordered experiences during dreams)  Alterations of Consciousness Unusual Experiences  Hallucinations Realistic perceptual experiences in the absence of external stimuli Not as rare as most people think: Sleep deprivation Migraines Sensory deprivation Intense emotion  Out-of-body Experiences A sense of consciousness leaving our body Reports of having experienced one or more: About 25% of college and university students About 10% of the general population report No evidence of a true perceptual experience  Near-Death Experiences An out-of-body experience is reported by people who have nearly died or thought they were going to die: Passing through a dark tunnel Experiencing a bright light Seeing our lives pass before our eyes Meeting spiritual beings or long-dead relatives No evidence of a true perceptual experience Déjà Vu A feeling of reliving a novel experience Frequency tends to decline with age Causes: Excess dopamine in the temporal lobes? Abnormal electrical activity in the right temporal lobe? Hypnosis Set of techniques that provide people with suggestions to alter their thoughts, perceptions, feelings, and behaviours A wide range of clinical applications for high and medium suggestibles High ~15-20% of people Medium ~ 60-70% of people Low ~15-20% of people  Myths of Hypnosis: Hypnosis produces a trance state in which “amazing” things can happen Hypnotic phenomena are unique Hypnosis is a sleep-like state Hypnotized people are unaware of their surroundings Hypnotized people ‘forget’ what happened during hypnosis Hypnosis enhances memory  Sociocognitive Theory of Hypnosis An approach to explaining hypnosis based on people’s attitudes, beliefs, and expectations People's expectations of whether they’ll respond to hypnotic suggestions are correlated with how they respond Dissociation Theory of Hypnosis An approach to explaining hypnosis based on a separation between personality functions that are normally well integrated When hypnotized, part of the mind is subject to suggestion, but other parts (known as “hidden observer”) remain awake/aware  Drugs and Consciousness  Substance Abuse vs. Dependence Substance abuse Recurrent problems associated with the drug Substance dependence A more serious pattern of use, leading to clinically significant impairment, distress, or both. Substance Abuse vs. Dependence Tolerance is a key feature in dependence Occurs when people need to consume an increased amount of a drug to achieve intoxication Physical vs. psychological dependence  Tolerance and Withdrawal Tolerance Decrease in responsivity to drug (need larger doses) Body attempts to maintain homeostasis Compensatory Responses Physiological reactions opposite to that of drug Brain is adjusting to body imbalances  Tolerance and Withdrawal Withdrawal Compensatory responses after drug use is discontinued Learning, Tolerance & Overdose Environment is a powerful influence Classical conditioning Environment becomes associated with drug Conditioned Drug Responses Tolerance for drug influenced by familiarity of drug setting In unfamiliar setting ‘overdose’ reaction can occur even when typical amount of drug is used  Myths about substance abuse: Drug tolerance always leads to significant withdrawal If a drug does not produce tolerance or withdrawal, one cannot become dependent. Physiological dependence major cause of addiction Drugs and Consciousness Psychoactive drugs: Chemicals similar to those found naturally in our brains Molecules alter consciousness by changing chemical processes in neurons The effects of drugs are due to: Chemical properties One’s mental set, or beliefs and expectancies, about the effects of drugs  Class Typical Effects Overdose Effects DEPRESSANTS Alcohol Relaxation, lowered inhibition, Disorientation, unconsciousness, depressed/impaired physical and possible death at extreme doses psychological functioning Barbiturates/Tranq Tension reduction, depressed reflexes and Shallow breathing, clammy skin, uilizers impaired motor functioning, induced sleep weak and rapid pulse, coma, possible death STIMULANTS Amphetamines Increased alertness, pulse, and blood Agitation, hallucinations, Cocaine pressure; elevated mood; suppressed paranoid delusions, convulsions, Ecstasy appetite; sleeplessness heart failure, possible death OPIATES Opium Euphoria, pain relief, drowsiness, impaired Shallow breathing, convulsions, Morphine motor and psychological functioning coma, possible death Heroin Oxycodone Fentanyl HALLUCINOGENS LSD Hallucinations and “visions,” distorted time Psychotic reactions (delusions, Mescaline perception, loss of reality contact, nausea, paranoia), panic that may lead Psilocybin restlessness, risk of panic to behaviour causing injury MARIJUANA Mild euphoria, relaxation, enhanced sensory Fatigue, anxiety, disorientation, experience, increased appetite, impaired sensory distortions, and possible memory and reaction time psychotic reactions Depressants Depressant drugs depress the effects of the central nervous system (CNS) Sedative means “calming”; Hypnotic means “sleep inducing” Alcohol and sedative-hypnotics (barbiturates and benzodiazepines) Depressants - Alcohol Small doses: Feelings of relaxation, elevate mood, lower inhibitions, and impair judgment Larger doses: Blood alcohol content (BAC) 0.05 to 0.10 Sedating and depressant effects more apparent Brain centres become depressed, slowing thinking and impairing concentration, walking, and muscular coordination  Short-term effects of intoxication are directly related to BAC. Women absorb alcohol faster than men, leading to a higher BAC when other factors are controlled (see graph). In Canada, BAC levels for illegal operation of a vehicle range from 0.05 to 0.08. Stimulants Stimulants ‘rev’ up your CNS A few popular ones are nicotine, cocaine, and amphetamines  Stimulants - Nicotine Activates receptors sensitive to the neurotransmitter acetylcholine Report feelings of stimulation as well as relaxation and alertness Adjustive value: Nicotine can enhance positive emotional reactions and minimize negative emotional reactions  Stimulants - Cocaine The most powerful natural stimulant! Blocks reuptake of norepinephrine & dopamine Users report: euphoria enhanced mental and physical capacity stimulation decrease in hunger indifference to pain sense of well-being accompanied by diminished fatigue *Sedatives - Hypnotics Used to treat acute anxiety and insomnia High doses have strong depressant effects Unconsciousness, coma, and even death! Three categories: Barbiturates (Nembutal, Seconal, etc.) Non-barbiturates (Qualaludes, Sopor) Benzodiazepines (Valium, Xanax) Narcotics Opiates, often called narcotics, relieve pain and induce sleep Heroine Morphine Codeine Heroine conveys a sense of euphoria Pleasurable effects in 3-4h that dose lasts If addicted to heroine, experience heroine withdraw syndrome if new dose not taken  Psychedelics / Hallucinogens Hallucinogenic (or psychedelic) because they produce dramatic alterations in perception, mood, and thought LSD, mescaline (“magic mushrooms”), PCP, Ecstasy Some researchers classify marijuana as a mild hallucinogen  LSD and other Hallucinogens Interfere with serotonin at the synapse Associated with areas of the brain rich in receptors for the neurotransmitter dopamine Can produce dramatic shifts in perceptions and consciousness: Common: clearing of thoughts, changes in sensations and perceptions, and mythical experiences Sometimes: produce panic, paranoid delusions, confusion, depression, and bodily discomfort Other Hallucinogens Ecstasy, a.k.a. MDMA (methylendioxymethaamphetamine) Stimulant and hallucinogenic properties Produces cascades of the neurotransmitter serotonin in the brain Side effects: high blood pressure depression nausea blurred vision liver problems sleep disturbance possible memory loss and damage to neurons that rely on serotonin! *Marijuana Marijuana was the most frequently used illegal drug in Canada! Effects of marijuana due to THC (delta-9-tetrahydrocannabinol) Users report short-termed effects: a sense of time slowing down enhanced sensations of touch increased appreciation for sounds hunger (the “munchies”) feelings of well-being a tendency to giggle  Marijuana Intoxicating effects can last for 2-3h No consistent evidence for serious physical health or fertility consequences from marijuana use Chronic, heavy use of marijuana can impair attention and memory