The Neurophysiological Objection
The Representationalist solution comes at a cost. In return for
resolving the epistemological question, Representationalism opens a new
paradox, and that is a glaring disparity between two primary sources
of knowledge, phenomenology and neurophysiology. Phenomenology
presents the mind as a three-dimensional colored structure or
analogical representation, while neurophysiology presents the brain
as an assembly of billions of discrete quasi-independent local
processors interconnected in a massively parallel network. Where in
that mass of neural circuitry are the three-dimensional volumetric
real-time moving pictures that we know so well in conscious
experience? The brain just seems to be the wrong kind of device to
create that kind of representation. Is consciousness therefore an
illusion with no direct neurophysiological correlate? Or is there
something fundamentally wrong with our understanding of
neurophysiology?
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The information that phenomenal experience gives us about the
external world is known to be somewhat uncertain, as we are easily
fooled by illusions, and occasionally by outright hallucinations. But
when the object of our phenomenological investigation is conscious
experience itself, our knowledge of that particular entity is very
certain. In fact our knowledge of our own conscious state is more
certain and reliable than any other knowledge we can possibly have,
even when our conscious experience is itself only a
hallucination. Neuroscience on the other hand is a science very much
in its infancy, and is rife with uncertainty. In fact the "dirty
little secret" of neuroscience, as Searle (1997, p. 198) calls it, is
that the central principles of representation and computation in the
brain remain to be discovered. Very little is known with any real
certainty about how perceptual or cognitive information is encoded in
the brain, or what kind of computation the brain actually performs in
perception. And there are several prominent aspects of brain activity
whose functional significance remains almost entirely obscure, such
as the synchronous oscillations observed between neurons in remote
cortical areas, and the global oscillations of the brain as a whole
as seen in Electroencephalogram (EEG) recordings. The
phenomenological inspection of conscious experience therefore offers
more reliable and certain knowledge of the essential principles of
mental representation and function than anything that modern
neuroscience has yet to offer, because it gives us direct access to
the massive quantities of information encoded in the brain, presented
in a form that is immediately meaningful to us. If our observations
of the nature of phenomenal experience are in conflict with
contemporary concepts of neurocomputation, it is our
neurophysiological theories which are in urgent need of revision in
order to bring them in line with observed phenomenologically. For a
neuroscience which explains everything about the brain except for how
it generates the mind, is a neuroscience which essentially explains
nothing, because it is the mind that makes the brain interesting in
the first place.