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Consciousness Chapter 4 Consciousness • • • Personal awareness of mental activities, internal sensations, and the external environment William James (1892) described it as a “stream” or “river” Allows us to integrate past, present, and future behavior Attention The capacity to selectively focus awareness on particular stimuli in your external environment or on you internal thoughts or sensations. You are always paying attention to something- but it’s not always the stimuli that you’re supposed to be paying attention to. Characteristics of Attention Attention has a limited capacity: Attention is selective: Compared to a spotlight that we shine on a particular stimuli or thought. Cocktail party effect: able to talk to one person even though you are surrounded by a lot of noise. Attention can be blind: We are faced with more information than we can process. We can’t pay attention to everything. We sometimes miss completely obvious stimuli in our vison or hearing. Multi-Tasking divides our attention and gives less attention to each task. Circadian Rhythm A cycle or rhythm that is roughly 24 hours long: the cyclical daily fluctuations in biological and psychological processes. body temperature Sleep/Wake cycle In the absence of time cues, the cycle period will become somewhat longer than 24 hours. The Suprachiasmatic Nucleus SCN: cluster of neurons in the hypothalamus that governs the timing of circadian rhythms. Also involves environmental cues- sun Melatonin: hormone manufactured by the pineal gland that produces sleepiness. Stages of Sleep Defined in terms of brain-wave patterns. Measured by an electroencephalograph or EEG. Electrodes placed on the scalp provide a gross record of the electrical activity of the brain. 4 different brain-wave patterns: Beta Alpha Theta Delta Stages of Sleep When you are awake and aware your brain emits beta waves. When you become relaxed and drowsy your brain switches to alpha waves. Hypnagogic hallucinations: vivid sensory phenomena that occur during the onset of sleep. Stages of Sleep • Stage 1 NREM: • • Drowsiness occurs and theta waves start (can still quickly wake if needed). Stages 2 NREM: • • • • Onset of true sleep. Defined by appearance of sleep spindles. Brief bursts of brain activity that last a second or two. K complexes: single but large high-voltage spike of brain activity. Awake Low-voltage, high-frequency beta waves Drowsy Alpha waves Stage 1 Sleep Theta waves Stage 2 Sleep mixed EEG activity Slow wave sleep (stage 3 and stage 4 sleep) Progressively more delta waves (stage 4 shown) REM sleep Low-voltage, high-frequency waves Stages of Sleep • • • Upon reaching stage 4 and after about 80 to 100 minutes of total sleep time, sleep lightens, returns through stages 3 and 2 REM sleep emerges, characterized by EEG patterns that resemble beta waves of alert wakefulness muscles most relaxed rapid eye movements occur dreams occur Four or five sleep cycles occur in a typical night’s sleep; less time is spent in slow-wave, more is spent in REM Stages of Sleep Stage 3 & 4 NREM: Slow-wave sleep When Delta waves represent more than 20% of brain activity, sleeper is in stage 3. When Delta waves exceed 50%, sleeper is in stage 4. REM Sleep: Brain becomes more active, smaller and faster brain waves. Visual and motor neurons activate. Dreams occur Sleep Across the Lifespan • • • • • • Sleep cycles emerge during prenatal development. Newborns sleep about 16 hours per day. By age 2, 75-minute sleep cycles are experienced. By age 5, typical 90-minute sleep cycles of alternating REM and NREM sleep emerge. Deeper slow-wave sleep decreases with age. Time in REM sleep increases during childhood and adolescence, remains stable throughout adulthood, and decreases during late adulthood. Sleep Deprivation • • • • Some individuals need more and some less than the typical 8 hours per night. After being deprived of sleep for just one night, microsleeps develop-episodes of sleep lasting a few seconds during wakefulness. Disruptions in mood, mental abilities, reaction time, perceptual skills, and complex motor skills occur with sleep deprivation. Most people are not good at judging the extent to which their performance is impaired by inadequate sleep. Effects of Sleep Deprivation • • • • • • • Moods become more volatile Harmful changes in levels of stress hormones Immune system compromised REM deprivation often results in REM rebound increasing REM by 50% Changes become more pronounced the longer the sleep deprivation The brain needs to experience the full range of sleep states, compensating when possible. http://www.cbsnews.com/news/the-science-of-sleep/ Dreams and REM Sleep • • Dream: An unfolding sequence of thoughts, perceptions, and emotions that typically occurs during REM Sleep thought—Vague, bland, thought like occurrences about real-life events that occur during NREM sleep. Psychoanalytic Interpretation • • • Manifest content—elements of the dream that are consciously experienced and remembered Latent content—the unconscious wishes that are concealed in the manifest content Dreams as “wish fulfillments” Activation Synthesis Model • Brain activity during sleep produces dream images (activation) that are combined by the brain into a dream story (synthesis). • Meaning is to be found by analyzing the way the dreamer makes sense of the progression of chaotic dream images. Neurocognitive Model Emphasizes the continuity of waking and dreaming cognition. States that dreaming is like thinking under conditions of reduced sensory input and the absence of voluntary control. Dreams reflect our interests, personality and individual worries. Sleep Disorders • • • Dyssomnias: category of disorders involving disruption in the amount, quality, or timing of sleep. Insomnia—inability to fall asleep or stay asleep Narcolepsy—overpowering urge to fall asleep that may occur while talking or standing up Sleep Apnea Breathing interruption that occurs during sleep. Do not start breathing again until they suddenly sit up and gasp for air. Once they start breathing again they go back to sleep. They are often tired throughout the day because they were waking up all night. Occurs when a person’s air passage is blocked. Associated with obesity and snoring. Can lead to heart attacks and strokes. Parasomnias • • • • • • • Undesirable physical arousal, behaviors, or events during sleep or sleep transitions Nightmare—different than sleep terror Sleepsex—involves abnormal sexual behaviors and experiences during sleep Sleepwalking—an episode involving walking or performing other actions during sleep Sleep-related eating disorder (SRED)—the sleeper will sleepwalk and eat compulsively REM sleep behavior disorder—a failure of the brain mechanisms that normal suppress voluntary actions during REM sleep Night terrors—sudden arousal from sleep and intense fear accompanied by physiological reactions (eg, rapid heart rate, perspiration) that occurs during slow-wave sleep Hypnosis • • • • • • State of awareness Highly focused attention Increased responsiveness to suggestion Vivid imagery Willingness to accept distortions of logic Alteration of sensation and perception Meditation • • Sustained concentration that focuses attention and heightens awareness Lowered physiological arousal decreased heart rate decreased blood pressure • Predominance of alpha brain waves Psychoactive Drugs • • • • • Depressants—inhibit brain activity Opiates—pain relief and euphoria Stimulants—increase brain activity Psychedelics—distort sensory perceptions Drug Abuse: Recurrent drug use that results in disruption of academic, social, or occupational functioning, or in legal or psychological problems Common Properties • • • • • Physical dependence: person has physically adapted to a drug so that he or she must take the drug in order to avoid withdrawal Tolerance: increasing amount of a drug are needed to produce desired effect Withdrawal symptoms: physical reactions that occur when a person stops using a drug that they are physically dependent on Drug rebound effect: withdrawl symptoms that are the opposite of a physically addictive drug’s actions Approximately 23 million Americans age 12 and older abuse or are dependent on psychoactive drugs (National Survey on Drug Abuse and Health). Depressants • • • • Alcohol—CNS depressant Barbiturates—downers; perscription sedatives; induce sleep Inhalants—inhaled; can cause relaxation or hallucinations Tranquilizers—xanax; relieve anxiety Alcohol • • • • About 17 million Americans have problems with alcohols. They drink heavily on a regular basis and suffer social, occupational, and health problems as a result of their drinking (Substance Abuse and Mental Health Services Administration, 2008). Alcohol lessens inhibitions by depressing the brain centers responsible for judgment and selfcontrol. Reduced inhibitions and self-control contribute to aggressive and violent behavior. Opiates • • • • Chemically similar to morphine and have strong pain-relieving properties Mimic the brain’s endorphins Heroin, methadone Percodan, Demerol Opiates Morphine, heroin, codeine. Morphine introduced during the Civil War to deaden the pain from battle wounds. Known as “soldier’s disease” Causes a surge of pleasure. Heroin was introduced in the West during the 1800’s. Was the “hero” that would cure morphine addiction. Named because it made people feel “heroic” Coming down can make a person have deep depression. Impair judgment, memory, cause drowsiness, and depress the respiratory system. Stimulants Increase activity of the nervous system. Speed up heart rate. Sense of well being or euphoria, or an enhanced ability to think and function. Can also cause anxiety, paranoia, reduced appetite, restlessness, and insomnia. Nicotine Amphetamines Cocaine Caffeine Caffeine • • • • • The most widely used psychoactive drug in the world Found in coffee, tea, cola drinks, chocolate, and certain over-the-counter medications Stimulates the release of dopamine in the brain’s prefrontal cortex. Is physically addictive, withdrawal symptoms can be seen: headaches, irritability, drowsiness, and fatigue can last a week or longer Excess caffeine use can produce anxiety, restlessness, increased heart rate, and disrupt normal sleep patterns Nicotine Drug found in tobacco leaves. Spurs the release of the hormone adrenaline. Causes heart rate to increase. As addictive as the use of heroin. 12-20 times as likely as non-smokers to die of lung cancer. Linked to death from heart disease, chronic lung and respiratory diseases, and other illnesses. Amphetamines • • • • • Methamphetamine is highly addictive and can cause extensive brain damage and tissue loss. First used by soldiers during WWII to stay awake and alert during the night. Destroys the neurotransmitter Dopamine in the brain Behavioral effects of losing dopamine receptors and transporters involve memory and motor skill and social skill problems. Depression, emotional instability, and impulsive and violent behavior are also common. http://www.rehabs.com/explore/meth-before-and-afterdrugs/infographic.html#.VgLpOdJVhBc Cocaine • • • • • An illegal stimulant derived from the leaves of the coca plant, which is found in South America. Produces intense euphoria, mental alertness, selfconfidence, reduces hunger and raises blood pressure. Cocaine blocks the reuptake of three different neurotransmitters – dopamine, serotonin, and norepinephrine. Cocaine reaches the brain in seconds and its effects peak in about 5 minutes. Schizophrenia-like symptoms develop from prolonged use (auditory hallucinations of voices and bizarrely paranoid ideas). Psychedelics Cause an overall change in perception, consciousness, thought and emotion. “Mixes up” the central nervous system, speeds things up and then slows things down randomly. Increases blood pressure, increased heart rate, and increased appetite. Flashback reactions and psychotic episodes Examples: Mescaline, LSD, Marijuana “Club” Drugs • Ecstasy (MDMA)—feelings of euphoria, increased well-being • • Side effects—dehydration, hyperthermia, tremor, rapid heartbeat Dissociative anesthetics (include PCP and Ketamine)—deaden pain, produce stupor or coma, may induce hallucinations