Dr. N.L. Kachhara
The third category refers to further developments or generalizations of present-day quantum theory.
Penrose and Hameroff
In the approach presented by Penrose and Hameroff, quantum theory is claimed to be effective for consciousness, but this happens in an extremely sophisticated way. It is argued that elementary acts of consciousness are non-algorithmic, i.e., non-computable, and they are neurophysiologically realized as gravitation-induced reductions of coherent superposition states in microtubule. Roger Penrose thinks that consciousness must be quantum phenomenon because neurons are too big to account for consciousness. In general, the collapse of the wave function is what gives the laws of nature a non-algorithmic element. Otherwise we would simply be machines and we would have no consciousness.
Microtubules are the main component of a supportive structure within neurons, known as the cytoskeleton. They are composed of tabulin protein dimer subunits. Tubulins have other smaller non-polar regions that contain pi-electron rich indole rings, and Hameroff claims that these electrons are close enough to become quantum entangled. These electrons could become locked in phase, forming BEC. These BEC could extend to many others, thus forming a macroscopic quantum feature across an extended area of the brain. When the wave function of this extended condensate collapsed, it could give access to non-computational influence related to mathematical understanding and ultimately conscious experience.
Hameroff further postulated that the activity of these condensates is the sources of gamma wave synchronization in the brain that has been viewed as a likely correlate of consciousness in conventional neuroscience.
Hameroff has pointed out that single cell organisms such as "paramecium" can perform quite complicated actions normally thought to need a brain. He suggests that their "brain" is in their microtubules (see BEC). Shape changes in the constituent proteins (tubulin) could sub serve computational functions and would involve quantum phenomena of the sort envisaged by del Guidice et al. This raises the intriguing possibility that the most basic cognitive unit is provided, not by the nerve cell synapse as is usually supposed, but by the microtubular structure within cells. The underlying intuition is that the structures formed by BEC are the building blocks of mental life; in relation to perception they are model of the world, transforming a nice view, say, into a mental structure which represents some of the inherent qualities of that view.
By and large, the ideas of Penrose and Hameroff represent a highly speculative approach with conceptual problems and without plausible concrete ideas for empirical confirmation. Jeffrey Reimers showed that coherent Frolich condensates, basis of Hameroff's postulate, could not exist in biological tissue.
