Facing Up to the Problem of Consciousness

The easy problems and the hard problem

  • the ability to discriminate, categorize, and react to environmental stimuli;
  • the integration of information by a cognitive system;
  • the reportability of mental states;
  • the ability of a system to access its own internal states;
  • the focus of attention;
  • the deliberate control of behavior;
  • the difference between wakefulness and sleep.
  • The really hard problem of consciousness is the problem of experience


    Functional explanation

    cognitive abilities and functions.

    How do we explain the performance of a function?
    By specifying a mechanism that performs the function. 

    [function, causation, explanation]

    What makes the hard problem hard and almost unique
    is that it goes beyond problems about the performance of functions. 

    no analogous further question in the explanation of genes, or of life, or of learning. 

    explanatory gap 

    This is not to say that experience has no function

    [correlation, causality, telekinesis]

    Some case-studies

    "neurobiological theory of consciousness"  Crick and Koch
    35-75 hertz neural oscillations in the cerebral cortex
    binding of information contents
    Binding is the process whereby separately represented pieces of information
    about a single entity are brought together to be used by later processing,
    as when information about the color and shape of a perceived object
    is integrated from separate visual pathways.
    these oscillations are the neural correlates of experience.
    the explanatory question remains:
    Why do the oscillations give rise to experience?

    Baars' global workspace theory of consciousness

    "Neural Darwinism" model of Edelman (1989)
    nothing about why there should also be experience
    "multiple drafts" model of Dennett (1991)
    "intermediate level" theory of Jackendoff (1988)

    Ways to beg the question:
    explain something else

    deny the phenomenon
    claim to be explaining experience

    explain the structure of experience
    isolate the substrate of experience

    The extra ingredient

    chaos and nonlinear dynamics
    nonalgorithmic processing Penrose (1989; 1994)
    discoveries in neurophysiology
    quantum mechanics.

    The moral of all this is:
    you can't explain conscious experience on the cheap

    reductive methods - systematic reasons why these methods must fail.

    vitalist claim that no physical account could explain life
    but the cases are disanalogous
    disanalogous to the élan vital

    Nonreductive explanation

    McGinn (1989)
    the problem is too hard for our limited minds

    conscious experience outside the domain of scientific theory altogether.

    "I think this pessimism is premature."
    nonreductive explanation 

    theory of consciousness should take experience as fundamental.
    Where there is a fundamental property, there are fundamental laws
    psychophysical principles will "not interfere" with physical laws,
    physical laws already form a closed system.
    they will be a supplement to a physical theory
    tells us how physical processes give rise to experience. 

    [How? Parallelism? Correlates? Causation? Explanation?]

    does not tell us why there is experience in the first place
    -- same for any fundamental theory

    [So, no answer to "Why?"]

    an innocent version of dualism

    theory of consciousness will have more in common
    with a theory in physics than a theory in biology

    this position still concedes an explanatory gap
    between physical processes and experience

    [How? Why? Causality needed, not just correlation.]

    Outline of a theory of consciousness

    This sort of analysis can yield a number of principles
    relating consciousness and cognition... a fundamental theory 


    A nonreductive theory of consciousness
    will consist in a number of psychophysical principles
    connecting the properties of physical processes to the properties of experience

    [Correlation, not causation, hence not an explanation]

    The principle of structural coherence.

    between the structure of consciousness
    and the structure of awareness

    [just correlation: redundant distinction,
    multiplying entities, question-begging]

    [access to processing vs "access" to consciousness:
    data/algorithms used vs. conscious (felt)
    why/how used is "easy"
    why/how felt is hard]

    contents of awareness:
    direct availability for global control
    directly accessible, potentially reportable

    [why/how aware/conscious/felt?]

    Awareness is a purely functional notion
    but it is nevertheless intimately linked to conscious experience

    [correlated: why/how felt?]

    Every subject's experience can be at least partly characterized and decomposed
    in terms of these structural properties: similarity and difference relations

    [Correlations: how? why?
    and what about commensurability?]

    For every distinction between color experiences
    there is a corresponding distinction in processing

    [JNDs: just-noticeable-differences:
    correlations: how/why felt?]

    The three-dimensional structure of phenomenal color space
    corresponds directly to the three dimensional structure of visual awareness

    [correlates: how/why felt?

    geometric structure of the visual field
    directly reflected in a structure that can be recovered from visual processing

    [correlated: how/why?]

    given only the story about information-processing
    in an agent's visual and cognitive system,
    we could not directly observe that agent's visual experiences
    but we could nevertheless infer those experiences' structural properties

    [Goal is not mind-reading (telepathy),
    but causal explanation (non telekinetic):
    how/why are "experiences" felt?]

    information that is consciously experienced
    will also be cognitively represented

    [unexplained correlation:
    simply restating the phenomenon
    how? why? otherwise merely
    redundant epiphenomenon]

    The fine-grained structure of the visual field
    will correspond to some fine-grained structure in visual processing

    [will correlate: how/why?]

    Even emotions have structural properties,
    such as relative intensity,
    that correspond directly to a structural property of processing

    [correlate: how/why? and commensurability?]

    this isomorphism
    between the structures of consciousness and awareness 
    constitutes the principle of structural coherence

    [Unexplained (and redundant)
    correlation: how/why?
    and commensurability?]

    principle allows us to recover structural properties of experience
    from information-processing properties

    [correlation allows prediction,
    but explanation requires causal mechanism]

    but not all properties of experience are structural properties:
    e.g. the intrinsic nature of a sensation of red
    cannot be fully captured in a structural description

    [the felt quality is all of the hard problem
    and it is not "captured" at all without
    explaining the correlations causally:

    inverted spectrum scenarios,
    where experiences of red and green are inverted
    but all structural properties remain the same,
    show that structural properties constrain experience
    without exhausting it

    [Without even touching the (hard) fact that
    experience is felt experience]

    The principle of structural coherence
    allows for a very useful kind of indirect explanation

    [No explanation: merely restatement of unexplained
    correlation between function and feeling]

    The coherence between consciousness and awareness
    also allows a natural interpretation of work in neuroscience
    directed at isolating the substrate (or the neural correlate) of consciousness.

    [Correlation allow interpretation of correlation
    as correlation, between behavior and brain function
    and between both of those and feeling:
    what is needed is how/why explanation
    of how/why the function is felt]

    if we accept the coherence principle
    we have reason to believe
    that the processes that explain awareness
    will at the same time be part of the basis of consciousness.


    The principle of organizational invariance.

    any two systems with the same fine-grained functional organization
    will have qualitatively identical experiences

    what matters for the emergence of experience
    is not the specific physical makeup of a system,
    but the abstract pattern of causal interaction between its components

    [some functions are implementation-independent
    some are not;
    all computation is imlementation-independent
    but cognitive function is not all computational function;
    computation is not causality;
    and none of this explains the correlation
    between function and feeling]

    reductio ad absurdum
    one system is made of neurons and the other of silicon,
    one experiences red where the other experiences blue
    imagine gradually transforming one into the other
    Along this spectrum, there must be two systems A and B 
    that are physically identical,
    except that a small neural circuit in A has been replaced by a silicon circuit in B.
    What happens when we flip the switch?
    By hypothesis, the system's conscious experiences
    will change; from red to blue,
    But there is no way for the system to notice the changes!
    Its causal organization stays constant
    so that all of its functional states and behavioral dispositions stay
    "dancing qualia"

    [Two equivocations:
    functionally equivalent is not the same as identical,
    only empirically identical is;
    so feelings could be changing, without their
    changingness itself being felt ("change-blindness")
    -- the incommensurability problem.
    But this is all just unconstrained speculation, as
    the (hard) question of the causal basis for the correlation
    is left as unexplained as ever]

    functionally isomorphic systems must have the same sort of experiences

    [Only empirical identity is 100% functional isomorphism: and that
    does not solve any problems: just shows computation is not causality,
    and cognition is not just computation]

    the only physical properties directly relevant 
    to the emergence of experience
    are organizational properties.

    [organization includes
    every structural JND;
    : how/why?]

    The double-aspect theory of information.

    direct isomorphism
    between certain physically embodied information spaces
    and certain phenomenal (or experiential) information spaces.

    [correlated: how/why?]

    information (or at least some information) has two basic aspects,
    a physical aspect and a phenomenal aspect

    [correlated: how/why?
    and all information?
    what about mereology (parts)?]

    physical changes that correspond
    to changes in conscious experience 
    are always relevant by virtue of their role in
    constituting informational changes 

    [correlated: how/why?]

    Wheeler (1990) 


    [ how/why felt information?]

    extremely speculative
    ...whether all information has a phenomenal aspect.
    mouse has a simpler information-processing structure than a human,
    correspondingly simpler experience
    perhaps a thermostat,
    might have maximally simple experience?

    physics characterizes its basic entities only extrinsically
    in terms of their relations to other entities,
    intrinsic nature of physical entities is left aside

    [how/why should anything be felt?]