6: Consciousness

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6 Consciousness

• Outline
• Basic issues
• Easy and hard problems
• Philosophical positions
• Neuroscientific Theory
• Crick Koch and the binding problem
• Philosophical Theories
• Searle
• Chalmers
• The Zombie Argument
• Dennett
• A view from psychology
• Learning Outcomes

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What is consciousness?

• We all know dont we?
• James (1910)
• Every thought or state of mind that one has
• Constant change between successive states
• Consciousness appears to us as a continuous flow
  or stream

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The asymmetry of consciousness

• Different mode of access to facts of
• Your own consciousness
• 1st person perspective
• Other peoples consciousness
• 3rd person perspective
• We know the phenomenology of conscious experience
  the qualia
• Cannot access someone elses first-person
  perspective
• Out of reach of scientific methods

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What is it like to be a bat?

• Subjective vs objective concepts
• what is it like? vs physical make-up
• We have no conception of the subjective side
• We dont know what it is like to be a bat
• There is something about experience that isnt
  covered by scientific description

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The problem is

• How does subjective consciousness fit into the
  objective world?
• How does it relate to the physical properties of
  the brain?
• NB 2 types of consciousness
• Access consciousness
• Rational control of behaviour
• Reasoning, action, speech
• Phenomenal consciousness
• Experiential states, qualia

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Easy and Hard problems

• Easy problem
• Objective study of the brain
• Causal roles played by psychological states
• How are these roles implemented in the brain?
• Essentially explanation of cognitive functions
• Chalmers (1995)
• Ability to discriminate, react to external
  stimuli, integrate information, report mental
  states, attention
• Susceptible to the methodology of cognitive
  psychology
• The easy problem is quite hard.
• But the hard problem is even harder!

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Easy and Hard problems

• Hard problem
• Phenomenal consciousness
• Where do feelings come from
• We can talk about the function of pain and the
  mental states involved, but why does it hurt?
• Functionalist problem
• We do not know what its function is
• Materialist problem
• We do not know what it is made of
• Experimental problem
• We cannot measure it directly

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3 viewpoints

• Dualist
• Conscious experience distinct from brain activity
• Property dualism (e.g. Chalmers)
• One substance, 2 properties
• Physical properties
• Conscious properties
• Materialist
• Unity of conscious experience and the brain
• Conscious states are physical brain states

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3 viewpoints

• Mysterian
• Consciousness is a complete mystery
• Colin McGinn (1989)
• how can technicolour phenomenology arise from
  soggy grey matter
• Awareness of colours cannot be the same thing as
  neurons firing
• Thomas Nagel
• We lack any conception of how mind and brain can
  be identical
• But do not want a dualism
• Non-material conscious states lack causal power
  over matter

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We need a theory!

• Which bits of the brain (which processes) are
  associated with consciousness?
• Obviously many processes do not yield conscious
  experience (e.g. hormone production, regulation
  of breathing)
• Do similar processes occur in other animals?
• Search for a theory independent of philosophical
  position.

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The Binding problem

• Integrated conscious experiences
• we experience everything as one event, e.g.
  sound, sight, our feelings and reactions
• But where is this theatre of the mind?
• Different sensations processed in different parts
  of the brain
• e.g. colour and shape are processed in different
  parts of the brain
• No nerve pathway system connecting these areas to
  a central place

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Crick Koch (1990) Neural Oscillations

• When we see objects, different features are
  processed in different areas of the visual cortex
• 2 objects cubic green box and cylindrical red
  hat
• Shape area cubic and cylindrical
• Colour area green and red
• Categorisation area box and hat
• Q. How do we bind cubic, green and box?
• A. Neural Oscillations
• Aspects of one object all associated with brain
  waves at the same frequency (35-75 Hz)
• Oscillations are neural correlate of visual
  consciousness

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Criticisms of Crick Koch

• Oscillations may be neural correlates of
  experience, but this doesn't explain why they
  give rise to experience.
• C K dont discriminate between between A- and
  P-consciousness. They are only addressing
  A-consciousness (or the easy problem).
• There is an explanatory gap
• How does neural oscillation give rise to
  consciousness?

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Searle biological naturalism

• Brain processes cause consciousness
• Processes cannot properly simulated
  computationally.
• Humans have semantics (and computer programs
  dont)
• This difference is because humans have
  consciousness
• Need to be able to interpret semantics
• Need to have consciousness to interpret

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Chalmers

• Qualia cannot arise from information processing
• The brain is an information processing device
• Therefore, consciousness must be a phenomena that
  attaches itself to information processing
  mechanisms
• So - consciousness has its own existence.
• We require a new fundamental property (alongside
  mass, space-time etc.)

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The Zombie argument

• Zombies
• Physically identical to us
• Behaviourally indistinguishable from us
• But they have no conscious experience
• Argument against materialism
• Do physical processes necessitate consciousness?
• If P necessitates C, we could not imagine a world
  containing P unless it also contains C
• A zombie world is imaginable
• So consciousness cannot be necessitated by any
  physical processes
• Consciousness cannot be explained in purely
  physical terms.

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The Zombie argument

• Dennetts response
• Zombies are impossible
• any being exhibiting sufficiently fine-grained
  behaviour and functionality of a conscious being
  WOULD BE a conscious being

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Dennett Multiple Drafts Model

• Functionalist - the hardware doesnt matter
• There is no stream of consciousness
• No theatre of the mind
• Instead, multiple specialist circuits
• Consciousness arises from processing information
  in a certain way

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Computation and consciousness

• Strong AI (Dennett)
• Consciousness consists entirely of computational
  processes.
• Weak AI.
• Brain processes cause consciousness
• Processes can all be simulated on a computer.
• Computational simulation will not be conscious.
• Non-Computational Naturalism (Searle)
• Brain processes cause consciousness
• Processes cannot properly simulated
  computationally.
• Non-Naturalism (Chalmers)
• Consciousness cannot be explained scientifically
  (computationally or otherwise).

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Problems

• How can any theory of brain structure/function
  account for phenomenal feel?
• But
• Is there really anything to explain?
• Is there anything its like to be a bat?
• Do qualia exist?
• Consciousness is a fascinating but elusive
  phenomenon it is impossible to specify what it
  is, what it does, or why it evolved. Nothing
  worth reading has been written about it.
  (Sutherland, 1989).

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An alternative viewpoint (OHara Scutt, 1996)

• We should ignore the hard problem
• The easy problem is a promising route to follow
• Pragmatic argument
• We know how to address the easy problems
• Context argument
• Understanding the easy problems will inform out
  understanding of the nature of the hard problem
• Epistemological argument
• We wont recognise a successful theory of the
  hard problem until we have a better understanding
  of what consciousness is

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Learning Outcomes

• Understand the basic issues in the study of
  consciousness and the ways in which these
  problems have been addressed by philosophers,
  neuroscientists and psychologists.

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Reading

• For next week, read
• Prelude Ant Fugue from Hofstadter, D. R.
  (1979). Gödel, Escher, Bach an eternal golden
  braid. London Penguin.
• Further Reading
• See lecture webpage or .pdf handout