I have been asked to write some thoughts on the quantum brain and, rather than just regurgitating Wikipedia, I thought I would give a thumbnail sketch of what I have learnt about quantum mechanics and about the brain over my lifetime. Since sometime in the seventies when aspects of quantum mechanics were popularised it has become convenient to try to marry some of its more esoteric aspects with the esoteric aspects of spirituality. That is a shame because it does neither discipline any favours. It is true that some parts of quantum mechanics are full of mystery and go against our common sense but that does not automatically qualify them as spiritual – they are just not part of our everyday experience and so appear as mysterious as thunder and lightning would have to the ancients.
So what is quantum mechanics and does it have any place in our understanding of the brain or of spirituality? Firstly I would like to declare that while I studied quantum mechanics for four years, it was some time ago and I am not a practitioner in professional life. As such my comments will be a simplified interpretation and not a statement of current thought in the field. Secondly, while we use a generic term for the quantum mechanics, it is a very broad field and there are probably about a dozen ways of interpreting the equations in anything like a practical way. (For your interest, I hold to the Copenhagen or Standard Model because that is what we were taught as undergraduates).
Quantum Mechanics is a field of study that considers particles and forces across very small dimensions. In general it covers things the size of or smaller than atoms although it has also been highly successful in predicting properties of some ordinary solids. Atoms are made up of protons, neutrons and electrons, and it is their interactions that can only be described by the mathematics of quantum mechanics. (There are also many other tiny particles that can be described as well although they are outside of the scope of this discussion).
Some of the strange phenomena that quantum mechanics predicts and describes include particles being waves and waves being particles; particles not being localised but having a location predicted by probabilities; pairs of particles forever linked once they have interacted; and perhaps the most provocative, that the outcome of an experiment is dependent on the observer of the experiment.
It is this last phenomenon that intrigues people the most because it is reasonable to ask how does the experiment know that the observer is there and has carried out the experiment? What aspect of the observer is crucial to this occurring? Is it the observer’s “consciousness” that washes over the experiment and influences the outcome (or more accurately causes the outcome to be realised from a sea of possible outcomes)? And so we start down the road of trying to attach a scientific justification (quantum mechanics) to something that hitherto has been in the realm of the spiritual. But is this justified or is it just lazy?
I saw a common misuse of the link between observer and observed today. The writer claimed that quantum physics says that the outcome of the experiment is “influenced” by the observer – that the brain waves of the observer directly influences the experiment. This is not true. Rather some interpretations of quantum physics say that the outcome of an experiment remains undetermined until the observer observes it – a significant difference. For example, if you can set up an experiment with two equally possible outcomes, say an atom can be spinning in one direction or another, then quantum physics says that the atom is actually spinning in both directions until the experimenter makes the measurement, after which it settles into one direction. In fact, the role of the observer in the experiment and whether consciousness is interacting with matter is still very much an open question. You can see how the simplified statement about the observer and the observed made many spiritual people quite excited but I am fairly sure that it is being used incorrectly to explain and justify a number of spiritual phenomena.
The brain is a magnificent organ and capable of so many things, but it is still mysterious as to how it manages to do so much. One of the most challenging questions is what makes a human brain different from an animal’s? Is it just larger? Although, as it is not the largest in the animal kingdom, size cannot be the only determining factor.Is it the design of the frontal cortex, and if so, why did no other animal proceed down this evolutionary path? And what is so clever about the design of the frontal cortex that it imbues us with reasoning, abstraction, planning, awareness of consequences, appreciation of beauty and so on? Is it just the extra surface area, leading to extra connections, leading to enhanced capacity or is there some mysterious extra feature beyond the physical brain that we don’t yet understand.
In recent times people have reached out for that popular workhorse, quantum mechanics, to offer some explanation for this higher functioning. Some of these models, loosely called the Quantum Brain, have been very well thought out and some have just tried to use a poorly understood quantum phenomena to brush over a poorly understood brain phenomena. And then of course there is the question of whether quantum mechanics can even be used in the field of anatomy because it is more commonly used at much smaller scales. Do quantum effects hold over distances larger than a couple of atoms?
So a very brief discussion of the scope of quantum mechanics is in order. At high school many of us learnt about atoms with their orbiting electrons because this simple model was all that was required to explain valence electrons, which are one of the main things that gives a particular atom its chemical properties. Of course, we know that quantum mechanics can be used to explain how the electrons sit around the nucleus and why there are shells of electrons and so on, but it is the presence and number of outer shell electrons that is key and we can get a pretty good understanding of basic chemistry without needing to factor in quantum effects.
Now as we go up the scale of the physical world from single atoms to groups of atoms (molecules), the quantum effects are less pronounced and can be described by relatively large scale chemical models. As we go to even larger molecules and group them at the cellular level, the quantum effects are largely ignored and the cell is described by a series of interacting chemical and physical processes. (There are a couple of situations where quantum principles are required in order to explain macroscopic phenomena however many of these are highly specialised physical arrangements or occur at extremely low temperatures). So once we get to structures as large as neurons within the brain, has quantum mechanics anything left to add? Does it make another appearance at this scale? At first sight the answer would probably be no. The only possibility that I am aware of would be to explain how electrical waves pass through and around the brain, but I need to read further to be sure.
So the Quantum Brain discussion seems to have a few strands to it. There are those who are genuinely looking around for an explanation of how the physical brain works, how memory works, how thoughts are created, transmitted and converted into action. For them it is natural to look beyond the physical/electrical/chemical processes that have been used for so long and to try out a physics theory that has been so useful at explaining other profound physical systems. Then there are those who are trying to understand consciousness, the thing that sets us apart from objective observers. This group are trying to understand whether one of quantum physics mysteries can be understood using a quantum model of the brain. Finally there are those who like the idea of applying something so trendy and poorly understood as quantum physics to something trendy and poorly understood like spirituality. They would like to attach some scientific credibility to their favourite subject and perhaps even use it to prove or disprove the existence of God.
That took far longer than I expected it to. I hope it has opened up some questions for the reader as it has for me. I marvel at the brain and its complexity. I am flummoxed as to how and why the human brain is capable of so much clever thought and wonderfully complex interaction. I still hold the spiritual side of me as mysterious and worthy of attention.