Chapter 4 States of Consciousness

1
Chapter 4States of Consciousness
2
Chapter 4 Overview

• What is consciousness?
• Circadian rhythms
• Sleep
• Dreams
• Psychoactive drugs

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What is Consciousness?

• Consciousness is everything of which we are aware
  at any given time-our thoughts, feelings,
  sensations and external environment

4
How have psychologists views about consciousness
changed since the early days of psychology?

• Early psychologists argued about what
  consciousness was and if it truly existed.
• Todays psychologists use brain-imaging
  techniques to identify brain activity associated
  with different states of consciousness
• They view consciousness as a neurobiological
  phenomenon, rather than an exclusively
  psychological one

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Circadian Rhythms

• More than 100 bodily functions and
• behaviors follow circadian rhythms
• fluctuating regularly throughout each day

6
In what ways do circadian rhythms affect
physiological and psychological functions?

• Circadian rhythm
• Regular fluctuation from high to low points of
  certain bodily functions and behaviors within a
  24-hour cycle
• Regulate all vital life functions
• Suprachiasmatic nucleus
• Structure in the hypothalamus
• The bodys biological clock
• Controls the timing of circadian rhythms
• Signals the pineal gland to secrete or suppress
  melatonin

7
How do disruptions in circadian rhythms affect
the body and the mind?

• Jet lag and working during subjective night
  disrupt circadian rhythms
• Can lead to sleep difficulty and reduced
  alertness
• Subjective night
• The time during a 24-hour period when the
  biological clock tells a person to go to sleep

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Sleep

• Before the 1950s, there was little understanding
  of what goes on during the state of consciousness
  know as sleep. From analyses of sleep recordings,
  known as polysomnograms, set up in sleep
  laboratories, researchers discovered two major
  types of sleep.

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Brain waves during sleep
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What is the difference between the restorative
and circadian theories of sleep?

• Restorative theory of sleep
• The function of sleep is to restore body and mind
• Circadian theory of sleep
• Sleep evolved to keep humans out of harms way
  during the night
• Also known as the evolutionary theory

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How do NREM and REM sleep differ?

• NREM sleep
• Non-rapid eye movement sleep
• Characterized by slow respiration and heart rate,
  little body movement, and low blood pressure and
  brain activity
• REM sleep
• Characterized by rapid eye movements, paralysis
  of large muscles, fast and irregular heart and
  respiration rates, increased brain activity, and
  vivid dreams
• REM sleep may be critical to the consolidation of
  new memories after learning

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Sleep cycles

• During a typical nights sleep, a person goes
  through about five 90-minute cycles

13
What is the progression of NREM stages and REM
sleep in a typical night of sleep?

• Stage 1
• Transition stage between waking and sleeping
• Irregular EEG waves some alpha waves
• Stage 2
• Deeper sleep than in stage 1
• Sleep spindles appear in EEG
• Stage 3
• Beginning of slow-wave sleep
• EEG registers 20 delta waves
• Stage 4
• Deepest stage of NREM sleep
• More than 50 delta waves

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How does age influence sleep patterns?

• Infants and young children
• Sleep the longest
• Have largest percentage of REM and slow wave
  sleep
• Children from 6 to puberty
• Sleep best
• Most consistent sleepers and wakers
• Adolescents
• Sleep patterns influenced by schedules
• Insufficient sleep may contribute to poor school
  performance
• Older adults
• More difficulty falling asleep sleep more
  lightly
• Spend more time in bed, but less time asleep

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Average hours of sleep across the lifespan
16
How does sleep deprivation affect behavior and
neurological functioning?

• Effects of sleep deprivation
• Difficulty concentrating
• Impaired learning
• Negative mood
• Effects on the brain
• Decreased activity in temporal lobes during
  verbal learning tasks
• Increased activity in prefrontal cortex and
  parietal lobes
• To compensate for decreased temporal lobe activity

17
What are the various disorders that can trouble
sleepers?

• Parasomnias is a sleep disturbance in which
  behaviors and physiological states that normally
  occur only in the waking state take place during
  sleep
• Somnambulism (sleepwalking)
• Occurs during partial arousal from stage 4 sleep
• Somniloquy (sleeptalking)
• Can occur in any stage
• Sleep terrors
• Sleeper awakes in panicked state
• Happens during stage 4 sleep
• Nightmares
• Frightening dreams during REM sleep

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What are the various disorders that can trouble
sleepers?

• Dyssomnia is a category of sleep disorder in
  which the timing, quantity, or quality of sleep
  is impaired
• Narcolepsy
• Disorder characterized by excessive daytime
  sleepiness and attacks of REM sleep
• Sleep apnea
• Disorder in which breathing stops during sleep
• Insomnia
• Difficulty falling or staying asleep, or waking
  too early
• Sleep that is light, restless, or of poor quality

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Dreams

• We generally think of dreaming as a pleasant,
  imaginative experience, but occasionally a
  frightening dream occurs. Good or bad, just what
  exactly is a dream?

20
What have researchers learned about dreams, their
biological basis, and their controllability?

• REM dreams
• Have a storylike quality
• More visual, vivid, and emotional than NREM
  dreams
• NREM dreams
• Occur during NREM sleep
• Less frequent and memorable than REM dreams

21
How do the views of contemporary psychologists
concerning the nature of dreams differ from those
of Freud?

• Dreams satisfy unconscious sexual and aggressive
  desires
• These wishes are unacceptable to the dreamer and
  must be disguised in symbolic forms
• Manifest content
• The content of a dream as recalled by the dreamer
• Latent content
• The underlying meaning of a dream

22
How do the views of contemporary psychologists
concerning the nature of dreams differ from those
of Freud?

• Activation-synthesis theory of dreaming
• Dreams are the brains attempt to make sense of
  random firing of brain cells during REM sleep
• Evolutionary theory of dreaming
• Vivid REM dreams enable people to rehearse skills
  needed to deal with threatening events

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Psychoactive Drugs

• Any substance that alters mood, perception, or
  thought
• Controlled substances are approved for medical
  use
• Illicit substances are illegal

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How do drugs affect the brains neurotransmitter
system?

• Psychoactive drugs create a sense of pleasure by
  increasing availability of dopamine in the
  nucleus accumbens, a part of the brains limbic
  system
• How drugs affect neurotransmission
• Opiates mimic the effects of endorphins
• Depressants act on GABA receptors
• Stimulants mimic the effects of epinephrine

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What is the difference between physical and
psychological drug dependence?

• Substance abuse
• Continued use of a substance after several
  episodes in which use has negatively affected an
  individual's work, education, and social
  relationships
• Physical drug dependence
• Compulsive pattern of drug use in which the user
  develops drug tolerance coupled with unpleasant
  withdrawal symptoms when the drug use is
  discontinued
• Psychological drug dependence
• A craving or irresistible urge for the drugs
  pleasurable effects

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How do stimulants affect behavior?

• Speed up activity in the central nervous system
• Suppress appetite
• Make people feel more awake, alert, and energetic
• Stimulants include
• Caffeine
• Nicotine
• Amphetamines
• Cocaine

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What are the behavioral effects of depressants?

• Decrease activity in the central nervous system
• Slow down bodily functions
• Reduce sensitivity to outside stimulation
• Sedative-hypnotics
• Alcohol
• Barbiturates
• Minor tranquilizers (benzodiazepines)
• Narcotics (opiates)
• Morphine, heroin
• Oxycontin, Vicodin

28
In what way do hallucinogens influence behavior?

• Drugs that can alter and distort perceptions of
  time and space, alter mood, cause hallucinations
• Also called psychedelics
• Hallucinogens include
• Marijuana
• LSD
• Designer drugs (e.g., MDMA or Ecstasy)