The description and location of consciousness:
Although it is the conventional wisdom that consciousness cannot be defined,
philosophers have been describing it for centuries. Rene Descartes wrote
Meditations on First Philosophy in the seventeenth century, and this contains
extensive descriptions of what it is to be conscious. Descartes described
consciousness as things laid out in space and time that are viewed from
a point. Each thing appears as a result of some quality such as colour,
smell etc. (philosophers call these qualities 'qualia'). Other philosophers
such as Nicholas Malebranche, John Locke, David Hume and Immanuel Kant
also agreed with much of this description although some avoid mentioning
the viewing point. The extension of things in time was considered in more
detail by Kant and James. Kant wrote that "only on the presupposition
of time can we represent to ourselves a number of things as existing at
one and the same time (simultaneously) or at different times (successively)".
William James stressed the extension of experience in time and said that
time is "the short duration of which we are immediately and incessantly
sensible". These philosophers also go on to describe dreams, thoughts,
emotions etc.
Philosophers have provided a description of consciousness that is like our own experience. When we look around a room or have a dream, things are laid out in space and time and viewed as if from a point. However, when philosophers and scientists consider the location of the contents of consciousness there are fierce disagreements. Some philosophers and scientists do not hold that every mental event has a direct physical event (weak or no 'Supervenience'). As an example, Descartes proposed that the contents of consciousness are images in the brain and the viewing point is some special, non-physical place without extension (the Res Cogitans). This idea is known as 'Cartesian Dualism'. Another example is found in the work of Thomas Reid who thought the contents of consciousness are the world itself which becomes conscious experience in some way through a chain of cause and effect. The precise physical substrate of conscious experience in the world, such as photons, photochemicals, quantum fields etc. is not specified. This idea of a chain of cause and effect or chain of relations causing conscious experience to supervene on the world is found in post-modernism and some forms of behaviourism.
Scientists tend to accept supervenience due to the causal arguments from neurochemistry and neuropathology which each strongly determine properties of consciousness (eg:Daniel Dennett and John Searle). The concept of supervenience is closely related to the idea of emergentism. It is sometimes held that consciousness will emerge from the complexity of brain processing (see for instance the Multiple Drafts Model of consciousness). The general label 'emergence' allows a new physical phenomenon to be implied by physicalist theorists without specifying the exact nature of the phenomenon. This leaves an explanatory gap. Indirect Realists see the explanatory gap in terms of phenomenal consciousness and have proposed various physical theories such as Quantum mind, space-time theories of consciousness and Electromagnetic theories of consciousness, which contain a direct correspondence between brain activity and experience. As yet there is little evidence from brain studies to support these theories. Direct Realists see the explanatory gap in terms of access consciousness and expect an explanation to emerge from an understanding of the complexity of neural processing.
Quantum mechanical approaches:
The physicist Roger Penrose, in his book Shadows of the Mind, argued for
a quantum mind approach, suggesting that non-local quantum mechanical
effects within sub-neural structures give rise to conscious states. He
has argued for the need for a fundamentally new physics in order to explain
consciousness, which he conceives as a fungible material: one of which
any portion can substitute another. ('Shadows' is effectively a second
edition of The Emperor's New Mind. Penrose is keen to stress that it replaces
that older work).
Penrose was not the first to suggest a link between consciousness and QM; Michael Lockwood and Henry Stapp got there first, and so did Brian Flanagan. Before them there was Bohr, the father of quantum mechanics (QM), who, as David Bohm tells us, "suggests that thought involves such small amounts of energy that quantum-theoretical limitations play an essential role in determining its character." Also of interest are the ideas of Weyl, Wigner, and Schrodinger. All of them shared in the view of consciousness as a fungible reality; adversaries of this stance call it "antipersonalism" and argue that such a construct has never been factually found.
The Uncollapsing theorem is an unproven conjecture that if an observer is in a deep altered state of consciousness they will not collapse the wavefunction of a system when they observe it but rather uncollapse it, meaning they can move the wavefunction into a wider possibility states. This would explain certain experiences of meditators who feel they move into a larger space of possibilities when they go into deep meditation.
In sum, no real evidence has been found to support any specific relationship between quantum mechanics and the occurrence of consciousness.
Criticism:
Some people criticize quantum mechanical theories of consciousness for
being just a result of an emotional desire of people who want to think
of their thoughts and emotions as being special and irreproducible by
known computational means. The basis for this criticism is the lack of
evidence for quantum mechanics playing a role in consciousness, combined
with the fact that quantum mechanics are still often regarded by those
people as being somewhat mystical and special.
Read more about Spiritual Approaches.
