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  • Writer's pictureRob Hamilton

Can consciousness be explained by Quantum Mechanics?

Updated: Jun 10

A recent article in the New Scientist magazine considers whether there is mounting evidence for the claim that consciousness is achieved through quantum events in the brain.  Let’s take a look at this from the Anything Goes perspective. 

The question of how consciousness is achieved has always been a fascinating mystery.  How does the coming together of atoms and molecules in a certain configuration result in the emergence of a perspective on the world, that experiences sights, sounds and emotions?  This amazing feat is known as the ‘Hard Problem’ of consciousness and it has puzzled scientists and philosophers for decades if not centuries. 

We have made so little progress in understanding the Hard Problem with the current tools at our disposal, that there is a sense that it will take something different; something truly wonderous, to achieve a breakthrough.  Perhaps that something is quantum mechanics?  Quantum mechanics is also something of an enigma, with its barrel of contradictions that appear to defy common sense.  If it can be shown that there are quantum goings on inside the brain, might that help us in our efforts to understand consciousness? 

One such idea that tries to make this connection is Orchestrated Objective Reduction (Orch OR), which says that consciousness arises when gravitational instabilities in the fundamental structure of space-time collapse quantum wavefunctions in tiny structures called microtubules that are found inside neurons.  This idea is obviously highly speculative, but might it have legs? 

The experiment covered in the New Scientist article investigated how the brain responds to certain anaesthetics.  We obviously know that anaesthetics affect consciousness – that is what we use them for.  But exactly how this happens is poorly understood.  The investigators concluded that the anaesthetic impacts the diffusion of energy in the brain’s microtubules in a way that can only be understood using quantum mechanics.  This result furthers our scientific knowledge, but obviously does not complete the picture - there are still further dots to join.  It doesn’t explain why it is that the change in the diffusion of energy in the microtubules results in a loss of consciousness. 

Cover of New Scientist dated 20 January 2024

The article then goes on to discuss work being done on the effect of anaesthetics on organoids (mini lab-grown brains).  The article considers whether an organoid might be sentient and quotes one of the scientists as saying “I would say it’s not conscious – pretty firmly” but another as being less sure. 

It is important to recognise that at this point, we are moving away from science and into the realm of metaphysics.  The word ‘consciousness’ is commonly used in two different ways, that are often conflated.  On the one hand, we talk about an entity being conscious if it responds to stimuli – the difference between being awake and having passed out, or being unconscious.  This is the kind of consciousness that is removed by administering an anaesthetic.  We might call this 'behavioural consciousness' because whether the entity is conscious or not is indicated by its behaviour. 

On the other hand, just because an entity is demonstrating behavioural consciousness doesn’t necessarily mean that there is anyone in there looking out.  A machine or a zombie could be programmed to respond to stimuli while being dead inside.  So what will be established if scientists finish this work of joining the dots? 

They will have identified the mechanism by which anaesthetics turn on and off behavioural consciousness, and perhaps may discover how behavioural consciousness is achieved more broadly.  This would be a fantastic achievement, but for many, it may fall a little flat.  Irrespective of whether or not behavioural consciousness is a result of quantum interactions, we will still have got no closer to understanding how sentience - this idea of a point of view on the world - arises.  So despite its importance, we perhaps can’t help but feel this work is a little mundane in comparison with the sexier challenge of the Hard Problem. 

Of course, graduates of the Rob Hamilton “Anything Goes” School of Metaphysics are aware that the Hard Problem is not just hard; it’s impossible.  And the reason it’s impossible is because the question is non-sensical.  You can’t explain the existence of something that is metaphysical in nature, as the product of physical interactions. The article talks about ‘Whether or not organoids have inner experience- there’s that much misunderstood term again!  AG students know that ‘inner experience’ needs to be understood within the context of our models of reality, otherwise it doesn't make sense as a concept. 

Neuroscientists tell us that the world we experience is a kind of model or 'controlled hallucination' given to us by our brains. The objects that we experience wouldn't exist if it wasn't for the fact that our brains conjure them up, as part of the way they make sense of that incoming data! Now you might argue that these objects still also exist in the real world - the brain just constructs a representation of them. But this is a heroic and unjustifiable assumption to be making. There is no reason to think that there is any one to one relationship between objects in the 'real world' and the objects constructed by our brains. And it is the objects constructed by our brains that have the properties by which we make sense of them. The map is the territory, as we like to say. The only way it can make sense to say that an object constructed by our brains has its own point of view, is as part of our way of conceiving it. And so the only inner experiences that entities have are those that we attribute to them in our models.

Let’s have another go at that sentence in the New Scientist and finish it in the Anything Goes way - Whether or not organoids have inner experience is a metaphysical judgment, much like whether or not someone is in pain.  When making this judgement, we need to make sure it is consistent with the level of behavioural consciousness we observe. We look at the evidence and form a view.  So to argue that a lab-grown brain sitting in a test tube might be conscious is analogous to claiming that someone cheerfully walking around with a smile on their face is internally suffering the agonies of the damned. While it's not completely ridiculous, it does stretch the limits of credibility.

There are lots of parallels here with the debate around the difference between the experience of pain and pain behaviour. If you would like to find our more, why not visit our website at A full exposition of the "Anything Goes" approach is provided in the book, Anything Goes: A Philosophical Approach to Solving the Hard Problem, coming summer 2024.  Why not sign up to our mailing list, to receive a notification when it is released and for further blog articles?

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