Towards Experimental Tests of Quantum Effects in Cytoskeletal Proteins

Abstract

This volume is appropriately titled “The Emerging Physics of Consciousness” and much of it is focused on using some aspect of “quantum weirdness” to solve the problems associated with the phenomenon of consciousness. This is sometimes done in the hope that perhaps the two mysteries will somehow cancel each other through such phenomena as quantum coherence and entanglement or superposition of wave functions. We are not convinced that such a cancellation can take place. In fact, finding that quantum phenomena are involved in consciousness, what we will call the “quantum consciousness idea” (QCI) (fathered largely by Penrose and Hameroff CHEXX[40, 102, 103]), is likely to confound both mysteries and is of great interest. In our contribution, we want to emphasize the “merging” part of this volume’s title by pointing out that there is a glaring need for properly controlled and reproducible experimental work if any proposed quantum phenomena in biological matter, let alone consciousness are to be taken seriously. There are three broad kinds of experiments that one can devise to test hypotheses involving the relevance of quantum effects to the phenomenon of consciousness. The three kinds address three different scale ranges associated roughly with tissueto-cell (1 cm–10 µm), cell-to-protein (10 µm–10 nm) and protein-to-atom (10 nm–1 Å) sizes. Note that we are excluding experiments that aim to detect quantum effects at the “whole human” or even “society” level as these have consistently given either negative results or been plagued by irreproducibility and lack of appropriate controls (e. g. the various extra sensory perception and remote viewing experiments CHEXX[72]). The consciousness experiments belonging to the tissue-cell scale frequently utilize apparatus such as electroencephalographs (EEG) or magnetic resonance imaging (MRI) to track responses of brains to stimuli. The best example of such is the excellent work undertaken by Christoff Koch’s group at Caltech CHEXX[61] sometimes in collaboration with the late Francis Crick CHEXX[22], tracking the activity of living, conscious human brain neurons involved in visual recognition. These experiments are designed to elucidate the multi- and single-cellular substrate of visual consciousness and awareness and are likely to lead to profound insights into the working human brain. Because of the large spatial and long temporal resolution of these methods, it is unclear whether they can reveal possible underlying quantum behavior (barring some unlikely inconsistency with classical physics such as, for instance, nonlocality of neural firing). The second size scale that is explored for evidence of quantum behavior related to aspects of consciousness (memory in particular) is that between a cell and a protein. Inspired by QCI, seminal experimental work has been done by Nancy Woolf CHEXX[142, 143] on dendritic expression of MAP-2 in rats and has been followed by significant experiments performed by members of our group on the effects of MAPTAU overexpression on the learning and memory of transgenic Drosophila (summarized in Sect. 4.3). Such attempts are very important to the understanding of the intracellular processes that undoubtedly play a significant role in the emergence of consciousness but it is hard to see how experiments involving tracking the memory phenotypes and intracellular redistribution of proteins can show a direct quantum connection. It seems clear that experimentation at this size scale can at best provide evidence that is “not inconsistent with” and perhaps “suggestive of” the QCI CHEXX[86]. The third scale regime is that of protein-to-atom sizes. It is well understood that at the low end of this scale, quantum effects play a significant role and it is slowly being recognized that even at the level of whole-protein function, quantummechanical (QM) effects may be of paramount importance to biological processes such as, for instance, enzymatic action CHEXX[4] or photosynthesis CHEXX[112]. In what follows, we give a brief overview of our theoretical QED model of microtubules and the extensive experimental work undertaken (belonging to the second and third size scales). We conclude by pointing towards directions of further investigation that can provide direct evidence of quantum effects in the function of biological matter and perhaps consciousness.