Chapter 4 Neural Correlates of Consciousness

Question 1

What are the Neural Correlates of
Consciousness?

Answer 1

• A neural correlate is an event in the nervous
  system that occurs at the same time as, and may
  be the biological basis of, a specific mental event
  or state.
  -Use neuroimaging (fMRI, PET) or EEG to track
  changes in brain activity when shifting from one
  state to another

Question 2

Brain Areas Involved

Answer 2

• There is no “consciousness center”
• Two categories of brain areas involved that
  correspond to the dimensions of consciousness.

Question 3

Neuronal Workspace Hypothesis

Answer 3

• A claim about how the brain makes conscious experience possible
• “Workspace neurons” link the activity of various
  specialized brain areas.
• Linking stimuli into a dynamic, coherent representation leads to consciousness.

Question 4

The binding problem

Answer 4

• How are different types of processing in various
  brain areas linked?
• Attention synchronizes neural firing in different
  systems
• Requires communication (via workspace neurons)
• Various mechanisms create competition among
  brain processes.
  -The winner (most active process) is communicated to
  other areas.
• Which elements win?
  -Attention involves activity in the prefrontal cortex.
  -It sustains and amplifies activity in other systems.
• Information flow is limited but controllable

Question 5

Function of the Neuronal Workspace

Answer 5

• The workspace makes possible a range of
  important behaviors.
  -Thinking about an object or idea after the stimulus
  has been removed (working memory)
  -Reflecting on relationships or combinations among
  various inputs or ideas (generativity, creativity)
  -Adjusting the processing in one system in light of
  what is going on in other systems (flexibility)
• When we are asleep, our brains are active
  but communication among brain areas is
  reduced.

Question 6

Qualia

Answer 6

• Access vs. Phenomenal
  Consciousness
• Your subjective experiences of sensation are sometimes called qualia, meaning the qualitative experiences of your conscious state.
• Because each of us experiences consciousness personally, we cannot know if any two people’s experiences, or qualia, are the same.
• Consciousness involves not just your sensations and thoughts but also your memories and anything else you are experiencing in the moment.

Question 7

The Role of Phenomenal Experience

Answer 7

• Processing fluency
  -Makes a stimulus seem special
  -It is part of conscious experience
  -Often interpreted as familiarity or accuracy of
  memories
• Consciousness leads to spontaneous and
  intentional behavior.
• Behavior of blindsight and amnesic patients
  suggest that perceptual information or memory
  has to be conscious before someone will put that
  information to use

Question 8

Consciousness: What Is Left Unsaid?

Answer 8

• Many questions remain about consciousness.
• Many questions about how consciousness can
  come from the brain fall under the mind‐body
  problem.
  -How the mind affects the body
  -How the body affects the mind

Question 9

Unresponsive wakefulness

Answer 9

• When people appear to have emerged from coma (their eyes are open, and they have sleep/wake cycles), yet do not respond to external stimuli for more than a month, they are in a condition called unresponsive wakefulness syndrome.
• This unresponsive state is not associated with consciousness. Normal brain activity does not occur when a person is in this state, in part because much of the person’s brain may be damaged beyond repair.
• The longer the unresponsive wakefulness lasts, the less likely it is that the person will ever recover consciousness or normal brain activity.

Question 10

Minimally-conscious state

Answer 10

• Some people who emerge from a coma are able to make deliberate movements, such as following an object with their eyes. They may even try to communicate. This situation is referred to as a minimally-conscious state.
• Differentiating between states of consciousness by behavior alone is difficult, but brain imaging may prove useful for identifying the extent of a patient’s injury and likelihood of recovery.

Question 11

Brain death

Answer 11

• The imaging of brain activity can also be used to tell whether a person is brain dead.
• Brain death is the irreversible loss of brain function.
• Unlike patients suffering from unresponsive wakefulness syndrome, who still show activity in regions of the brain stem, with brain death, no activity is found in any region of the brain.