Monday, March 4, 2013

The quantum brain and consciousness

I’ve been having an on-going discussion with a colleague about mind-brain duality and the nature of consciousness – when we both came across a piece of writing (author unknown) which goes something like this:

“If we work up a competent knowledge of the physics and electrical engineering of our TV sets, that knowledge will not help us to decide how far to trust the person talking on the screen". This was in the context of Mari Jibu and Kunio Yasue’s theoretical framework, Quantum Brain Dynamics (QBD) to help examine consciousness scientifically.

I wanted to pull together my thoughts and at the same time try and better understand QBD. This work seems to be based on the original physical theory of memory and brain functioning found in the work by Ricciardi and Umezawa in the 1960s. Jibu and Yasue aim to reveal the kind of physical phenomena that might underpin the process of consciousness from a physical point of view.

As we know there are numerous models explaining consciousness and even George Orwell's Nineteen Eighty-Four bleak outlook is a contender in Daniel Dennett's multiple drafts model of consciousness; a theory of consciousness based upon Cognitivism.

David Bohm took the view that quantum theory and relativity contradicted one another, and that this contradiction implied that there existed a more fundamental level in the physical universe pointing towards a deeper theory. This more fundamental level was proposed to represent an undivided wholeness and an implicate order, from which arises the explicate order of the universe as we experience it.

Bohm's proposed implicate order applies both to matter and consciousness, and he suggests that it could explain the relationship between them. Mind and matter are here seen as projections into our explicate order from the underlying reality of the implicate order. Bohm claims that when we look at the matter in space, we can see nothing in these concepts that helps us to understand consciousness.

Bohm sees the movement, change or flow and also the coherence of experiences, such as listening to music as a manifestation of the implicate order. He claims to derive evidence for this from the work of Jean Piaget in studying infants. Bohm, however, never proposed any specific brain mechanism by which his implicate order could emerge in a way that was relevant to consciousness, nor any means by which the propositions could be tested or falsified.

Roger Penrose and Stuart Hameroff collaborated to produce the theory known as Orchestrated Objective Reduction (Orch-OR) although each initially developing their ideas independently.  Penrose came to the problem from the point of view of pure mathematics and in particular Gödel's theorem.

Gödel, in 1931 proved that any theory capable of expressing elementary arithmetic cannot be both consistent and complete. Further to that, for any consistent formal theory that proves certain basic arithmetic truths there is an arithmetical statement that is true, but not provable in the theory. To put this in more simple terms; any system which is expressive enough to be consistent and complete is also expressive enough to contain self-referential statements which doom it to incompleteness.

In the 1989 book, The Emperor's New Mind, Penrose argued that the theorem showed that the brain had the ability to go beyond what could be achieved by axioms or formal systems. He argued that this meant that the brain had some additional function that was not based on algorithms.   

Penrose went on to consider what it was in the human brain that was not driven by algorithms. Given the algorithm-based nature of most of physics, he decided that the random choice of position etc. that occurs when a quantum wave collapses into a particle was the only possibility for a non-computable process. However, Penrose conceded that the randomness of the wave function collapse, although free from algorithms, is not really a basis for any useful form of human understanding.

Penrose proposed a second form of wave function collapse that could apply where quanta did not interact with the environment, but might collapse on their own accord. He suggests that each quantum superposition has its own piece of space-time curvature, and when these become separated by more than the Planck length, they become unstable and collapse.

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