F.Y.I. here is what Mr. Penrose thinks.
Roger Penrose
The theoretical physicist, Roger Penrose and the anaesthesiologist, Stuart Hameroff, collaborated to produce the theory known as Orchestrated Objective Reduction Orch-OR. Penrose and Hameroff initially developed their ideas separately, and only later cooperated to produce Orch-OR. Penrose came to the problem from the point of view of mathematics and in particular Godel's theorem, while Hameroff came from a career in cancer research and anaesthesia.
Godel's theorem is central to this theory. In 1931, Godel 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 theory.
The theorem is not in itself controversial, but what Penrose developed from it is. In his first book on consciousness, 'The Emperor's New Mind' (1989), 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 (a system of calculations), whereas a computer is driven solely by algorithms. Penrose asserted that the brain could perform functions that no computer could perform. He called this type of processinng non-computable.
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 admitted that the randomness of the wave function collapse, although free from algorithms, is not a basis for any useful form of human understanding.
Penrose now 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 spacetime curvature, and when these become separated by more than the Planck length of 10^-35m, they become unstable and collapse. Penrose called this form of collapse objective reduction.
Penrose suggested that objective reduction represented neither randomness nor the algorithm based processing of most physics, but instead a non-computable influence embedded in the fundamental level of spacetime geometry from which mathematical understanding and by later extension of the theory, consciousness derived.
When he wrote his first book on consciousness, The Emperor's New Mind in 1989, Penrose lacked a detailed proposal for how quantum processing could be implemented in the brain. Subsequently, Hameroff read Penrose's book, and suggested that microtubules could be suitable candidates for quantum processing. The Orch-OR theory arose from the collaboration of Penrose and Hameroff in the early 1990s.
Microtubules are the main component of a supportive structure within neurons known as the cytoskeleton. In addition to providing a supportive structure, the known functions of microtubules include transport of molecules including neurotransmitters bound for synapses and control of the development of the cell.
Microtubules are composed of tubulin protein dimer subunits. The tubulin dimers each have hydrophobic pockets that are 8 nm apart, and which may contain delocalised pi electrons. Tubulins have other smaller non-polar regions that contain pi electron-rich indole rings separated by only about 2 nm, and Hameroff claims that these electrons are close enough to become quantum entangled [14].
Hameroff further proposed that these electrons could become locked in phase, forming a state known as a Bose-Einstein condensate [15][16]. Furthermore, he thought that condensates in one neuron could extend to many others via gap junctions between neurons, thus forming a macroscopic quantum feature across an extended area of the brain. When the wave function of this extended condensate collapsed, it was suggested that this could give access to non-computational influences related to mathematical understanding and ultimately conscious experience that are embedded in the geometry of spacetime.
Hameroff further postulated that the activity of these condensates is the source of gamma wave synchronisation in the brain. This synchronisation has also been viewed as a likely correlate of consciousness in conventional neuroscience, and it has been shown to be linked to the functioning of gap junctions[17].[18][19][20][21][22][23][24][25][26][27]. .
Another neuroscientist, Danko Georgiev, has provided a foot note to the Orch-OR theory. He accepts much of Penrose's ideas, but criticises a good part of Hameroff's scheme. He proposes that quantum coherence on the surface of the microtubules extends via presynaptic scaffold proteins to the synapses, where it both influences synaptic firing, and is transmitted across the synaptic cleft to other neurons.[28][29][30]