Chapter 4 States of Consciousness

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Chapter 4States of Consciousness
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What is Consciousness?

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

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Altered States of Consciousness

• Altered state of consciousness
• A change in awareness produced by sleep,
  meditation, hypnosis, or drugs

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Circadian Rhythms

• Regular fluctuation from high to low points of
  certain bodily functions and behaviors within a
  24-hour cycle
• Regulate all vital life functions

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Influence of Circadian Rhythms

• Suprachiasmatic nucleus
• Structure in hypothalamus
• Bodys biological clock
• Controls timing of circadian rhythms
• Signals pineal gland to secrete or suppress
  melatonin

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Disruptions in Circadian Rhythms

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

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Sleep Deprivation

• Effects
• Difficulty concentrating
• Impaired learning
• Negative mood
• Effects on 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

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Why Do We Sleep?

• Circadian theory of sleep
• Sleep evolved to keep humans out of harms way
  during night
• Also known as evolutionary theory
• Restorative theory of sleep
• function of sleep is to restore body and mind
• Day-light savings time study

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How do we study sleep?

• EEG measures brain waves
• EOG measures eye movements
• EMG measures muscle activity
• Beta waves
• Alpha waves
• Theta waves
• Sleep spindles
• Delta waves
• REM sleep

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Sleep Cycles

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

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Types of Sleep NREM and REM

• NREM sleep
• Slow respiration and heart rate, little body
  movement, and low blood pressure and brain
  activity
• REM sleep
• Rapid eye movements, paralysis of large muscles
  (atonia), fast and irregular heart and
  respiration rates, increased brain activity, and
  vivid dreams
• REM without atonia
• REM sleep may be critical to consolidation of new
  memories

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Sleep Cycles cont

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

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Sleep Cycles (90 minutes)

• 1 2 3 4 3 2 REM
• REM 2 3 4 3 2
• 2 3 2 REM
• REM 2 REM 2

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Figure 4.1 Brain-Wave Patterns Associated with
Different Stages of Sleep
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Content of Our Dreams

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

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Interpreting DreamsFreud royal road to
unconscious.

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

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Interpreting Dreams cont

• Activation-synthesis theory of dreaming
• Dreams are brains attempt to make sense of
  random firing of neurons 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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Figure 4.2 Average Hours of Daily Sleep across
Life Span
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Sleep Disorders

• Parasomnias a sleep disturbance in which
  behaviors and physiological states that normally
  occur only in waking state take place during
  sleep
• Exclusively occur in Stage 4 (except sleep
  talking)
• Sleepwalking
• Sleeptalking
• Sleep driving
• Sleep eating
• Sleep terrors

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Sleep Disorders cont

• Dyssomnia timing, quantity, or quality of sleep
  is impaired
• Sleep apnea
• Insomnia
• Narcolepsy
• Cataplexy

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Psychoactive Drugs

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

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How Drugs Affect the Brain

• Create a sense of pleasure by increasing
  availability of dopamine in nucleus accumbens
• How drugs affect neurotransmission
• Opiates mimic effects of endorphins
• Depressants act on GABA receptors
• Stimulants mimic effects of epinephrine

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Substance Abuse and Addiction

• 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 user
  develops drug tolerance coupled with unpleasant
  withdrawal symptoms when drug use is discontinued
• Psychological drug dependence
• A craving or irresistible urge for drugs
  pleasurable effects

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Stimulants

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

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Depressants

• Decrease activity in 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

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Hallucinogens

• 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)