Chapter 4 Ppp


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Chapter 4 Ppp

  1. 1. Consciousness and Its Variations
  2. 2. Consciousness <ul><li>Described as a stream or river by William James </li></ul><ul><li>Introspection tried to capture the structure of consciousness </li></ul><ul><li>Modern study includes roles of psychological, physiological, social, and cultural influences </li></ul>
  3. 3. Circadian Rhythm <ul><li>Any rhythmic change that continues at close to a 24-hour cycle in the absence of 24-hour cues </li></ul><ul><ul><li>body temperature </li></ul></ul><ul><ul><li>cortisol secretion </li></ul></ul><ul><ul><li>sleep and wakefulness </li></ul></ul><ul><li>In the absence of time cues, the cycle period will become somewhat longer than 24 hours </li></ul>
  4. 5. The Body’s Clock <ul><li>Suprachiasmatic nucleus (SCN)—cluster of neurons in the hypothalamus that governs the timing of circadian rhythms </li></ul><ul><li>Melatonin—hormone of the pineal gland that produces sleepiness </li></ul><ul><li>Bright light decreases production of melatonin; decreased light increases melatonin </li></ul>
  5. 6. Electroencephalogram (EEG) <ul><li>Electrodes placed on the scalp provide a gross record of the electrical activity of the brain </li></ul><ul><li>EEG recordings are a rough index of psychological states </li></ul>
  6. 7. EEG Waves of Wakefulness <ul><li>Awake, but non-attentive: large, regular alpha waves </li></ul><ul><li>Awake and attentive: low amplitude, fast, irregular beta waves </li></ul>1 second Alpha waves Awake, nonattentive 1 second Beta waves Awake, attentive
  7. 8. Stages of Sleep <ul><li>Awake but sleepy--relaxed. alpha waves seen in EEG </li></ul><ul><li>Stage 1 NREM-- brief transition stage when first falling asleep--theta waves </li></ul><ul><li>Hypnogogic hallucinations--vivid sensory phenomena during onset of sleep </li></ul>
  8. 9. Stages of Sleep <ul><li>Stage 2 NREM--characterized by sleep spindles--brief spurts of activity </li></ul><ul><li>Stages 3 and 4 NREM (slow-wave sleep): successively deeper stages of sleep </li></ul><ul><li>Characterized by an increasing percentage of slow, irregular, high-amplitude delta waves </li></ul><ul><li>Stage 4 NREM is very deep sleep </li></ul>
  9. 10. Stages of Sleep <ul><li>Upon reaching stage 4 and after about 80 to 100 minutes of total sleep time, sleep lightens, returns through stages 3 and 2 </li></ul><ul><li>REM sleep emerges, characterized by EEG patterns that resemble beta waves of alert wakefulness </li></ul><ul><ul><li>muscles most relaxed </li></ul></ul><ul><ul><li>rapid eye movements occur </li></ul></ul><ul><ul><li>dreams occur </li></ul></ul><ul><li>Four or five sleep cycles occur in a typical night’s sleep; less time is spent in slow-wave, more is spent in REM </li></ul>
  10. 11. The 90-Minute Cycles of Sleep
  11. 12. Sleep Changes Throughout Life <ul><li>Changes in quality and quantity are apparent </li></ul><ul><li>Amount of time in deep (slow wave) and REM sleep decreases with age </li></ul>
  12. 13. Functions of Sleep <ul><li>Restoration theory—body wears out during the day and sleep is necessary to put it back in shape </li></ul><ul><li>Adaptive theory—sleep emerged in evolution to preserve energy and protect during the time of day when there is considerable danger </li></ul>
  13. 14. Sleep Deprivation <ul><li>Microsleep--episodes lasting only a few seconds </li></ul><ul><li>REM rebound--deprivation of REM sleep causes increase in time spent in REM sleep to “catch up” </li></ul><ul><li>NREM rebound--catching up on Stages 3 and 4 sleep </li></ul>
  14. 15. Individual Differences in Sleep Drive <ul><li>Some individuals need more and some less than the typical 8 hours per night </li></ul><ul><li>Nonsomniacs—sleep far less than most, but do not feel tired during the day </li></ul><ul><li>Insomniacs—have a normal desire for sleep, but are unable to and feel tired during the day </li></ul>
  15. 16. Sleep Disorders <ul><li>Insomnia—inability to fall asleep or stay asleep </li></ul><ul><li>Night terrors—sudden arousal from sleep and intense fear accompanied by physiological reactions (e.g., rapid heart rate, perspiration) that occur during slow-wave sleep </li></ul><ul><li>Narcolepsy—overpowering urge to fall asleep that may occur while talking or standing up </li></ul>
  16. 17. Sleep Disorders <ul><li>Restless Legs Syndrome--RLS unpleasant sensations in lower legs and urge to move legs disrupts sleep. </li></ul><ul><li>Sleep apnea—failure to breathe when asleep </li></ul><ul><li>REM sleep behavior disorder—sleeper acts out his or her dreams </li></ul>
  17. 18. Dreams and REM Sleep <ul><li>True dream—vivid, detailed dreams consisting of sensory and motor sensations experienced during REM </li></ul><ul><li>Sleep thinking—lacks vivid sensory and motor sensations, is more similar to daytime thinking, and occurs during slow-wave sleep </li></ul>
  18. 19. Brain and REM Sleep <ul><li>Active areas during REM--amygdala and hippocampus </li></ul><ul><li>Inactive areas during REM--frontal lobes and primary visual cortex </li></ul><ul><li>REM sleep plays a role in memory consolidation </li></ul>
  19. 20. Significance of Dreams <ul><li>Psychoanalytic Interpretation </li></ul><ul><li>Activation Synthesis Model </li></ul>
  20. 21. Psychoanalytic Interpretation <ul><li>Manifest content—elements of the dream that are consciously experienced and remembered </li></ul><ul><li>Latent content—the unconscious wishes that are concealed in the manifest content </li></ul><ul><li>Dreams as “wish fulfillments” </li></ul>
  21. 22. Activation Synthesis Model <ul><li>Brain activity during sleep produces dream images (activation) which 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. </li></ul>
  22. 23. Hypnosis <ul><li>State of awareness </li></ul><ul><li>Highly focused attention </li></ul><ul><li>Increased responsiveness to suggestion </li></ul><ul><li>Vivid imagery </li></ul><ul><li>Willingness to accept distortions of logic </li></ul><ul><li>Alteration of sensation and perception </li></ul>
  23. 25. Hypnosis and Memory <ul><li>Posthypnotic suggestion--during hypnosis a suggestion is made for the person to carry out some behavior after hypnosis is over </li></ul><ul><li>Posthypnotic amnesia--inability to remember specific information because of a posthypnotic suggestion </li></ul><ul><li>Hypermnesia--enhancement of memory because of posthypnotic suggestion </li></ul>
  24. 26. Meditation <ul><li>Sustained concentration that focuses attention and heightens awareness </li></ul><ul><li>Lowered physiological arousal </li></ul><ul><ul><li>decreased heart rate </li></ul></ul><ul><ul><li>decreased BP </li></ul></ul><ul><li>Predominance of alpha brain waves </li></ul>
  25. 27. Meditation Techniques <ul><li>Concentration techniques--control attention by focusing awareness on a visual image, word, or phrase </li></ul><ul><li>Opening-up techniques--control attention by focusing on the “here and now” </li></ul>
  26. 28. Psychoactive Drugs <ul><li>Depressants—inhibit brain activity </li></ul><ul><li>Opiates—produce pain relief and euphoria </li></ul><ul><li>Stimulants—increase brain activity </li></ul><ul><li>Psychedelics—distort sensory perceptions </li></ul>
  27. 29. Common Properties <ul><li>Physical dependence </li></ul><ul><li>Tolerance </li></ul><ul><li>Withdrawal symptoms </li></ul><ul><li>Drug rebound effect </li></ul>
  28. 30. Drug Abuse <ul><li>Recurrent drug use that results in disruption of academic, social, or occupational functioning or in legal or psychological problems </li></ul>
  29. 31. Depressants <ul><li>Alcohol—CNS depressant </li></ul><ul><li>Barbiturates—induce sleep but can cause dependence and as a result serious withdrawal symptoms </li></ul><ul><li>Tranquilizers—relieve anxiety but can be addictive </li></ul><ul><li>Effects are additive </li></ul>
  30. 33. Areas of the brain that may be affected by FAS
  31. 34. Opiates <ul><li>Chemically similar to morphine and have strong pain-relieving properties, can be addictive </li></ul><ul><li>Mimic the brain’s endorphins </li></ul><ul><li>Heroin, methadone </li></ul><ul><li>Percodan, Demerol </li></ul>
  32. 35. Stimulants <ul><li>Caffeine </li></ul><ul><li>Nicotine </li></ul><ul><li>Amphetamines </li></ul><ul><li>Cocaine </li></ul><ul><li>Stimulant induced psychosis </li></ul>
  33. 36. Psychedelics <ul><li>Create perceptual distortions </li></ul><ul><li>Mescaline </li></ul><ul><li>LSD </li></ul><ul><li>Marijuana </li></ul><ul><li>Flashback reactions and psychotic episodes </li></ul>
  34. 37. “ Club” Drugs <ul><li>Ecstasy (MDMA)—feelings of euphoria, increased well-being </li></ul><ul><li>Side effects—dehydration, hyperthermia, tremor, rapid heartbeat </li></ul><ul><li>Dissociative anesthetics—include PCP and Ketamine. Deaden pain, produce stupor or coma, and may induce hallucinations. </li></ul>