PSYC 1113 Chapter 4


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PSYC 1113 Chapter 4

  1. 1. Chapter 4:Consciousness andIts Variations
  2. 2. Consciousness• Can be characterized as the “Private I”• Personal awareness of mental activities,internal sensations, and the externalenvironment• William James (1892) described it as a“stream” or “river”; unified and unbroken
  3. 3. Circadian Rhythm• Any rhythmic change that continues at closeto a 24-hour cycle in the absence of 24-hourcues– body temperature– cortisol secretion– sleep and wakefulness• In the absence of time cues, the cycle periodwill become somewhat longer than 24 hours
  4. 4. The Body’s Clock• Suprachiasmatic nucleus (SCN)—cluster of neurons in thehypothalamus that governs the timingof circadian rhythms• Melatonin—hormone of the pinealgland that produces sleepiness
  5. 5. Electroencephalogram (EEG)• Electrodes placedon the scalpprovide a grossrecord of theelectrical activity ofthe brain• EEG recordingsare a rough indexof psychologicalstates
  6. 6. EEG Waves of Wakefulness• Awake, butdrowsy: large,alpha brainwaves1 secondAlpha waves1 secondBeta wavesAwake, attentive• Awake andalert: beta brainwaves
  7. 7. Stages of Sleep• Sleep stage 1: brieftransition stage whenfirst falling asleep• Stages 2 through 4(slow-wave sleep):successively deeperstages of sleep• Characterized by anincreasing percentageof slow, irregular, high-amplitude delta waves Delta wavesSleep stage 11 secondSleep stage 4Sleep stage 2Spindles (bursts of activity)
  8. 8. Stages of Sleep• Upon reaching stage 4 and after about 80 to 100minutes of total sleep time, sleep lightens, returnsthrough stages 3 and 2• REM sleep emerges, characterized by EEG patternsthat 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’ssleep; less time is spent in slow-wave, more is spentin REM
  9. 9. Sleep Deprivation• Has little effect on performance of tasksrequiring physical skill or intellectualjudgment• Hurts performance on simple, boring tasksmore than challenging ones• Most reliable effect is sleepiness itself• REM rebound—when a person who isdeprived of REM sleep greatly increases theamount of time spent in REM sleep whengiven the time
  10. 10. Individual Differencesin Sleep Drive• Some individuals need more and someless than the typical 8 hours per night• Nonsomniacs—sleep far less than most,but do not feel tired during the day• Insomniacs—have a normal desire forsleep, but are unable to sleep and feeltired during the day
  11. 11. Functions of Sleep• Restorative theory—body wearsout during the day and sleep isnecessary to put it back in shape• Adaptive theory—sleep emergedin evolution to preserve energy andprotect the body during the time whenthere is little value and considerabledanger in being awake
  12. 12. Dreams and REM Sleep• True dream—vivid, detailed dreamsconsisting of sensory and motor sensationsexperienced during REM• Sleep thought—lacks vivid sensory andmotor sensations, is more similar to daytimethinking, and occurs during slow-wave sleep
  13. 13. Lucid dreaming-Awareyou aredreaming.A lucid dream can begin in oneof two ways.1.A dream-initiated lucid dream startsasanormal dream, andthedreamer eventually concludesit isadream.2.A wake-initiated lucid dream occurswhen thedreamer goesfrom anormal waking statedirectly into adream state, with noapparent lapsein consciousness. Thewake-initiated luciddream "occurswhen thesleeper entersREM sleep withunbroken self-awarenessdirectly from thewaking state-
  14. 14. Dreams and REM SleepWhat are true dreams for?• Psychoanalytic interpretation• Activation synthesis model
  15. 15. Psychoanalytic Interpretation• Manifest content—elements of thedream that are consciouslyexperienced and remembered• Latent content—the unconsciouswishes that are concealed in themanifest content• Dreams as “wish fulfillments”
  16. 16. Activation Synthesis Model• Brain activity during sleep producesdream images (activation) that arecombined by the brain into a dreamstory (synthesis)• Meaning is to be found by analyzingthe way the dreamer makes sense ofthe progression of chaotic dreamimages
  17. 17. Sleep Disorders• Insomnia—inability to fall asleep or stay asleep• REM sleep disorder—sleeper acts out his or herdreams• Night terrors—sudden arousal from sleep andintense fear accompanied by physiological reactions(eg, rapid heart rate, perspiration) that occurs duringslow-wave sleep• Narcolepsy—overpowering urge to fall asleep thatmay occur while talking or standing up• Sleep apnea—failure to breathe when asleep
  18. 18. Parasomnias(undesirable physical arousal, behaviors, or eventsduring sleep or sleep transitions)• Sleep terrors (night terrors)—occur in the first fewhours of sleep during stage 3 or 4 NREM sleep• Nightmare—different than sleep terror• Sleepsex—involves abnormal sexual behaviors andexperiences during sleep• Sleepwalking—an episode involving walking orperforming other actions during sleep• Sleep-related eating disorder (SRED)—thesleeper will sleepwalk and eat compulsively• REM sleep behavior disorder—a failure of thebrain mechanisms that normal suppress voluntaryactions during REM sleep
  19. 19. Hypnosis• State of awareness• Highly focused attention• Increased responsiveness tosuggestion• Vivid imagery• Willingness to accept distortions of logic• Alteration of sensation and perception
  20. 20. Meditation• Sustained concentration that focusesattention and heightens awareness• Lowered physiological arousal– decreased heart rate– decreased blood pressure• Predominance of alpha brain waves
  21. 21. Psychoactive Drugs• Depressants—inhibit brainactivity• Opiates—pain relief and euphoria• Stimulants—increase brainactivity• Psychedelics—distort sensoryperceptions
  22. 22. Common Properties• Physical dependence• Tolerance• Withdrawal symptoms• Drug rebound effect
  23. 23. Drug AbuseRecurrent drug use that results indisruption of academic, social, oroccupational functioning, or in legalor psychological problems
  24. 24. Depressants• Alcohol—CNS depressant• Barbiturates—induce sleep• Inhalants—can cause relaxationor hallucinations• Tranquilizers—relieve anxiety
  25. 25. OpiatesChemically similar to morphine andhave strong pain-relieving properties• Mimic the brain’s endorphins• Heroin, methadone• Percodan, Demerol
  26. 26. Stimulants• Caffeine• Nicotine• Amphetamines• Cocaine— Stimulant-induced psychosis
  27. 27. Psychedelics• Create perceptual distortions• Mescaline• LSD• Marijuana— Flashback reactions and psychoticepisodes
  28. 28. “Club” Drugs• Ecstasy (MDMA)—feelings ofeuphoria, increased well-beingSide effects—dehydration,hyperthermia, tremor, rapid heartbeat• Dissociative anesthetics (includePCP and Ketamine)—deaden pain,produce stupor or coma, may inducehallucinations