Consciousness

1
Consciousness Altered States of Consciousness

• Consciousness
• Sleep
• Hypnosis
• Drugs

2
Definitions of Consciousness Allow Its Empirical
Study

• Subjectivity and qualia
• How do we know that your idea of red and my idea
  of red are the same idea?
• Access to Information
• We have access to some information in our minds
  (i.e., our consciousness), but we dont have
  access to other information in our minds (i.e.,
  our unconscious)
• Unitary Experience
• The outputs of our sensory systems are unified
  into a phenomenal experience that is continuous
  over time

3
Manipulating objects with the mind

• Implant small electrodes in the frontal and
  parietal lobe of a monkey
• Record electrical activity in those areas while
  the monkey is using a joystick to manipulate a
  robotic arm
• Create an index for the robotic arm, such that
  certain patterns of brain activity indicate
  certain movements
• Unplug the joystick and make movement of the
  robotic arm completely dependent on brain
  activity
• Within days, the monkey was able to control the
  robotic arm with only its thoughts

4
Variations in conscious experience

• Automatic vs. controlled processing
• Typically, automatic processing is fast and is
  done without much conscious effort (e.g., driving
  on a dry highway without much traffic)
• Typically, controlled processing is slower and is
  done with conscious effort (e.g., driving on a
  wet highway with a lot of traffic)
• Comas vegetative to minimally conscious
• Brain imaging can help determine the nature of
  the coma
• Thalamic stimulation

5
The Corpus Callosum

• Millions of myelinated axons connecting the
  brains hemispheres
• Provides a pathway for communication between the
  hemispheres
• If surgically severed for treatment of epilepsy,
  hemispheres cannot communicate directly

6
Visual Processing

• Both eyes send information to both hemispheres
• Right half of the visual field goes to the left
  hemisphere
• Left half of the visual field goes to the right
  hemisphere

7
Sperrys Split-Brain Experiment

• Split-brain subjects could not name objects shown
  only to the right hemisphere
• If asked to select these objects with their left
  hand, they succeeded but they could not say why
• The right side of the brain doesnt control speech

8
The interpreter

• The left hemisphere likes to construct a world
  that makes sense.
• It may even seek patterns that might not exist.

9
Unconscious Processing Influences Awareness

• The case for unconscious influence
• Subliminal perception (see next slide)
• Freudian slips
• Priming
• The smart unconscious
• Incubation effects
• Verbal overshadowing
• Blindsight
• Global workspace model of consciousness

10
Subliminal Perception

• Priming is quicker retrieval of words related to
  previous stimuli
• Priming works even if previous words are
  presented subliminally
• That is, the words are presented in such a way
  that the subject claims not to have perceived
  them.
• This is more evidence for the influence
  unconscious processing on awareness.

11
Sleep and Dreams

• Measuring Sleep
• Stages of Sleep
• Why Do We Sleep?
• Dreams
• Sleep Disturbances

12
Measuring Sleep

• Electrodes measure
• eye movements
• EMG
• Electromyogram
• EEG
• Electroencephalogram
• A camera may also record body movements

13
Stages of Sleep
14
A Typical Nights Sleep

• Typically 4-5 episodes of REM sleep per night
• Later episodes are longer and farther apart
• Most deep sleep (stages 3 4) occurs early

15
Sleep disorders

• Insomnia
• Pseudoinsomnia
• Worrying
• Cognitive-behavioral therapy can help
• Sleep apnea
• Narcolepsy
• Sleepwalking (somnambulism)

16
Why do we sleep

• Restoration
• Sleep allows the body to repair itself.
• Sleep deprivation
• Microsleeps
• Can cause problems with mood and cognitive
  performance
• Circadian Rhythms
• Keep animals quiet and inactive during the most
  dangerous part of the day (night for humans)
• Consolidation
• Neuronal connections that serve as the basis for
  new learning is strengthened during sleep.

17
Who Sleeps How Much?
18
Dreams

• Recalling dreams is rare, but dreaming isnt
• A normal person may dream 150,000 times in their
  lifetime
• People report dreams 80 of the time during REM
  sleep, but less than 50 of the time during other
  stages
• REM dreams are more bizarre non-REM dreams are
  often boring
• People have less REM sleep with age
• In newborns, 50 of sleep is REM
• In the elderly, about 20 of sleep is REM

19
What Do We Dream About?

• 64 of dreams associated with sadness, fear, or
  anger
• Aggressive acts outnumbered friendly acts by 21
• 18 of dreams were happy or exciting
• 29 of dreams were in color

20
Dream Theories

• Sigmund Freud believed that dreams expressed
  wishes, often disguised
• Manifest Content
• Conscious dream content that is remembered after
  awakening
• Latent Content
• The unconscious, uncensored meaning of a dream
• Alan Hobson activation-synthesis theory
• Random activation from the pons and the amygdala
  activate visual systems and memory systems and
  the mind attempts to interpret these random
  patterns

21
Sleep Disturbances

• Insomnia
• Inability to fall asleep, stay asleep, or get
  enough sleep to function during the day
• Hypersomnia (Narcolepsy)
• A type of irresistible, sudden attacks of
  drowsiness during the day
• Parasomnia (Sleep disturbance)
• Apnea Repeated cessation of breathing during
  sleep

22
Hypnosis
23
Hypnosis

• Hypnotic induction
• Attention-focusing procedures in which changes in
  a persons behavior or mental state are suggested
• Hypnotic Susceptibility
• The extent to which an individual is
  characteristically responsive to hypnosis
• Posthypnotic suggestion
• A suggestion made to a subject in hypnosis to be
  carried out after the induction session is over

24
Can Hypnosis Enhance Eyewitness Testimony?

• Participants saw videotape of a staged bank
  robbery
• Half were then hypnotized
• Re-intervivew mentioned robber wore a mask
• There was no mask
• In highly hypnotizable subjects, 63 had false
  memories

25
The Hidden Observer

• Subjects held a hand in ice water and reported
  pain
• Hypnotized subjects reported lower pain
• Hypnotized subjects reported a hidden observer
  that was aware of the pain

26
How Do Drugs Affect Consciousness?

• People Useand AbuseMany Psychoactive Drugs
• Alcohol Is the Most Widely Abused Drug
• Addiction Has Psychological and Physical Aspects

27
People Useand AbuseMany Psychoactive Drugs

• Marijuana
• most widely used illegal drug
• Stimulants
• Cocaine and amphetamines (speed, meth, etc.)
• improve mood
• cause restlessness and disrupt sleep
• MDMA (ecstasy)
• similar effects as stimulants, with slight
  hallucinations
• Opiates
• Heroin, morphine, codeine
• Highly addictive due to dual activation of
  dopamine and opiate receptors

28
Alcohol Is the Most Widely Abused Drug

• Alcoholism is the third largest health problem,
  following heart disease and cancer
• Currently 5 of all Americans are active
  alcoholics
• Another 3 are addicted to other drugs
• Lifetime prevalence is 10-20
• Americans have a love/hate relationship with
  alcohol
• On the one hand, moderate drinking is an accepted
  aspect of normal social interaction and may even
  be good for health.
• On the other hand, alcohol is a major contributor
  to many of our societal problems, such as spousal
  abuse and other forms of violence.

29
Alcohol Is the Most Widely Abused Drug

• Expectations
• alcohol reduces anxiety
• alcohol increases social skills, sexual pleasure,
  confidence, and power
• Reality
• large doses of alcohol result in negative moods
  and focus on problems and anxieties
• Alcohol impairs motor processes, information
  processing, mood, sexual performance
• Learned beliefs about intoxication influence
  behavior

30
Addiction Has Psychological and Physical Aspects

• Addiction
• a physiological state in which failing to ingest
  a substance leads to symptoms of withdrawal, a
  state characterized by anxiety, tension, and
  craving
• Physical dependence
• associated with tolerance, so that a person needs
  to consume more of the substance to achieve the
  same subjective effect
• Psychological dependence
• habitual and compulsive engagement despite the
  consequences
• people can be psychologically dependent without
  showing tolerance or withdrawal
• individuals can be psychologically dependent on
  behaviors like gambling, shopping, exercising, or
  internet use