Thursday, January 08, 2009

Microtubules and consciousness?

I've finished reading "Shadows of the Mind" by Roger Penrose. It was a very interesting book with interesting views (the view from physics). Dr. Penrose enters into a long explanation with arguments on his theories, one of the most interesting being the role of microtubules in consciousness. At the end of the book, Dr. Penrose asserts that consciousness cannot be invoked by machines, devices or biological entities which are only composed of computational algorithms and actions. That is, he asserts that something non-computational needs to become part of the equation in order for consciousness to exist.

The arguments are compelling in the book. If consciousness is evoked not by the neurons, but by the smaller microtubules that are part of neuronal cells, then the computational power of the mind exceeds the computational power of computers even further, by a factor of 100,000 or so.

Although at the same time, I'm not so sure about how this theory holds. The book is very explanatory about quantum theory and mechanics and explains a number of different puzzles and examples in quantum theory. One of the key questions it poses is the state vector reduction problem (collapse of the wave function), which is the process inbetween the quantum world and the classical world as we experience it.

Another thing I did not yet see anywhere is the concept as in the previous post, the likelihood of algorithms that influence one another. Thus, rather than a single algorithm which is executed by a single thread or CPU, is consciousness actually the collection of calculations in different threads / CPU's at the same time?

The very interesting thing of the book, if the consciousness is evoked by microtubules, is that neurons are then clusters of calculations, which influence other clusters. Like macro-signals of tiny little calculations that are then sent to other positions where the information is used as input for further calculations. It also may have some relevance to memory?

In connection with other posts, I have written about consciousness and reasoning as be it some kind of fluid algorithm, where the possibilities and concepts are tied loosely together as some kind of oil, with the thread of thought passing through it guiding the selected items. Items that are connected to others on the thread may appear in thoughts, given certain changes in context.

Then we could also make the point that, if Penrose's ideas are true, that microtubules are able to evoke any thought whatsoever, where the choice for the exact thought or idea to come up is made through some sort of calculation or determination. Thus, just as in quantum theory, the thought is not clear and could be any, but through a range of filters or possibilities, the final thought is evoked by the final filter.

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