(artwork by Diana Zanfirache)

Some people challenge the posit that consciousness is a product of the brain. They claim that if we do not know exactly how inanimate material can produce consciousness – how the complex interactions of billions of individual neurons actually produces self-awareness – then basing our experience in the brain is an unfounded claim. Furthermore, people are apparently being too hasty in referring to the material basis of thought when arguing that free will is an illusion. What if there is something else, entirely unbeknownst to us, that actually spawns consciousness? Some assert that free will could exist there.

Before I continue, I will devote a quick moment to explaining what I mean by free will, and why it is an illusion. (The subject deserves a lot more attention though, and I plan on expanding on this in a future essay). Free will^⁠1 is the notion that we are free to choose our thoughts and actions at any given moment. In turn, it implies that we could have done differently in the past – not due to some random occurrence, but because we as the conscious authors chose differently.

However, with the discovery of the scientific method, we have come to realise that we live in a universe dictated by pervasive physical laws. Indeed, the knowledge of these laws has allowed us to predict and manipulate our environment, and the idea that our minds are truly free suffers when one considers that we, humans, are part of this environment. There is no reason to believe that the laws of the universe do not govern our brains, and thus human thought, behaviour and actions. Nothing we know about neuroscience, biology, chemistry or physics can make any coherent sense of the idea of free will.

There is no inclination of a ghost in the machine, and we as conscious beings cannot step outside of the causal stream of events of the universe. At every instant the state of your brain, and thus mind, is dependent on prior states that preceded it. We could trace this chain of events back, through each moment to moment occurrence – to yesterday, last month, last year, to your birth, and beyond. And whether the universe is truly deterministic, or inherently involves indeterministic behaviour of particles at the quantum level, no amount of indeterminism results in free will, for how could we claim responsibility for truly random processes?

With these points in mind, many are forced to refer to our gap in understanding between matter and consciousness as a place for free will to exist. This reminds me of the well known god of the gaps argument – the attempt made by some to explain a phenomenon unexplained by scientific enquiry by saying ‘god did it’, thus proving his existence. This is not only an intellectually lazy strategy, it is ultimately futile, as we’ve witnessed this gap shrink smaller and smaller with scientific advancement. Lightning, disease, planetary motion and the origin of the diversity of life were all once part of this gap. Similarly, to say that there may be something else that explains consciousness in a way that allows free will to survive is a free will of the consciousness gap argument.

Consciousness has not been coined  ‘The Hard Problem’ for nothing.  For something as important as, ultimately, the only thing that can be important, we know embarrassingly very little about it.  The only evidence we really have of conscious experience is the experience itself. Furthermore, as the philosopher Rene Descartes famously said, “I think, therefore I am” entails that our consciousness is the only fact we can assert as an absolute truth about anything at all. All of what you experience could be a dream, a projected holographic universe, or part of a Matrix-type world whilst you’re living in a vat hooked up to wires. The only thing you can be sure about however is that you alone exist, in some sense, somewhere.

Sitting around and mulling on this point is no doubt intriguing, however it does not appear to achieve much more than that. In a universe in which we are conscious creatures, we cannot yet step outside of reality (or our consciousness) and peer in. Instead, we must work within our perspective. Stephen Hawking and Leonar Mlodinow tackled this issue in their book ‘The Grand Design’, as a prelude to diving into questions such as the fabric of the cosmos itself. Here they coined the term “model-dependent realism”, which reminds us that if we observe the universe from our perspective, make predictions based on those observations, and these predictions hold true, then this is as real as we can achieve. Laws of basic motion will appear differently to a fish within a curved glass bowl looking outwards to the world (due to the bending of light through the glass), but those laws will remain as real as they are to us. Neither perspective can be said to be more ‘real’.

So what observations and predictions can we make about consciousness? Well, firstly we must ask ourselves another question, a deceptively difficult one to answer – what is consciousness? One account, is that consciousness exists if there is ‘something that it is like’ to be that thing. Your current state of subjective experience is consciousness, whereas a rock is not conscious, because there is nothing that it is like to be a rock.

For the moment, we cannot step into another’s mind to study it – so how do we learn of the contents of another’s consciousness? The simplest way is by verbal report – what you tell me about your perceptions, memories and intentions. You can describe what you see, what event you are remembering, or your emotional state. Obviously there will be occasions where such reporting is not perfect, but, in general, the method works well. Such reporting is the basis of most human communication, upon which our relationships and wider society can function. I validate my understanding of your report by matching your description to my experience. The practise of psychiatry largely relies on verbal reports of subjective experience. If someone reports hearing the devil in the corner of the room, and I cannot see it, I ascertain that the patient is likely experiencing an auditory hallucination.

Verbal reporting provides a platform on which we can make observations and predictions about consciousness upon. An elegantly simple example involves the retina and the subjective experience of sight. Anatomically and developmentally, the retina is an extension of our brain, and physical perturbations of the retina produce predictable and reproducible alterations to the conscious experience of sight. This can be shown easily with an Amsler Grid – a card containing several rows of horizontal and vertical straight lines that is utilised by ophthalmologists to test your vision. By gazing on a dot in the centre, one can screen their central visual field for any defects. Not only does the experience of curved lines indicate a physical aberration of the retina (say for instance, a cyst underneath the retina causing a bump), but the location and degree of the curving correlates with the position and severity of the physical distortion of the retina. Here we have a simple phenomenon showing a clear relationship between the specific arrangement of neurons and consciousness.

Other types of damage to the brain also cause specific alterations in conscious experience. One way of conceptualising this is picturing your brain as a house, with each room representing an anatomical section of the brain. Rooms in this house are illuminated by lightbulbs, but these can burn out and blow. If the light in the room representing your parietal-medial-temporal lobe goes out, you will notice your ability to experience memories will suffer. Alternatively, if the light for the fusiform gyrus turns off, you lose the ability to recognise faces (known as ‘prosopagnosia’). Despite this, lights to nearby rooms may remain on, leaving other aspects of visual processing (such as object discrimination) and intellectual functioning completely intact.

Of course it is not always as simple as this, the circuitry of the brain is quite complex. Some defunct switches may control lights in multiple rooms^⁠2, doors left ajar can capture light from nearby rooms^⁠3, and inhabitants (or ‘functions’) of a darkened room can move next door and share with their neighbours^⁠4. But what I’ve tried to illustrate is that through alterations of the brain, components of the mind can be identified, separated, and individually affected. Furthermore, it shows the absurdity of the notion that the mind could survive the death of the brain. It implies that we could walk through the house of a brain, turn off the lights to each room, but as soon as the very last light goes out, the entire house immediately reilluminates in some other, completely non-physical, sense.

One of the most profound examples of the physical basis of consciousness involves instances where the brain is dissected at the corpus callosum, the area that connects the right and left hemispheres of your brain. This was done in the past as a means to treat severe medication-resistant epilepsy, by constraining the seizure activity of the brain to one half. Amazingly, this procedure left patients with what can be described as two separate consciousnesses. Studies into this phenomenon took advantage of the fact that each half of our visual field is processed by the opposite, or contralateral, side of the brain. If an experimenter flashed the command “DRINK” to the right hemisphere (by keeping it in the part of the visual field that only the right hemisphere could see), the person would comply and drink the glass of water in front of them. But when the  person’s left hemisphere was asked why they drank the water, they will say, in all sincerity, “because I was thirsty”—rather than “you told me to”, “I don’t really know” or “the urge just came over me”. One half of the brain was consciously aware of reading the instructions, whilst the other was not.

Through all these examples, it is clear there is a relationship between the physical brain and consciousness. As I’ve outlined above, alterations to the brain such as trauma, surgery, medications and tumours can directly affect consciousness. Although we may not yet know exactly how individual neurons – when plentiful enough and connected in the right ways – produce self-awareness, it seems that for every state of consciousness there is an associated neural state. Indeed, there has never been any evidence of a change in mental state occurring without a corresponding change in neural state.  So consciousness appears to be dependent on the brain.

But isn’t it possible that something else is involved in the gap between neurons and consciousness, something that we have never considered? Yes, but the possibilities would be effectively infinite. What’s worse, is that invoking something else entirely to explain consciousness, such as an immaterial or abnormal substance, complicates the matter further without providing any solution to the problem it claims to solve. For what is the evidence that this ’something else’ exists? What anchors it to particular bodies and brains? What property would allow this ’something else’ to think whilst brain material cannot?

Grounding our mental lives in the physical brain could easily be falsified. Our scientific concept of the brain and mind would immediately be thrown into disarray by any respectable evidence of ghosts, auras, the afterlife, or reincarnation, but alas this has not eventuated. (For those tempted to refer to the widely popular book “Proof of Heaven” by neurosurgeon Eben Alexander, please read this wonderful critique by neuroscientist and author Sam Harris).

By contrast, those who assert the existence of ‘something else’ to fill the gap between brains and consciousness cannot say what would count as evidence against their views, resulting in an uncanny similarity with religious faith. What would count as evidence of a supernatural being? Many things. What could prove its non-existence? Nothing. We must remember that a non-falsifiable argument is a sign of its weakness, not its strength. If free will exists, it cannot exist within the bounds of this reasoning.

¹ Libertarian free will.

² e.g Multiple Sclerosis.

³ Cognitive compensation.

⁴ Neuroplasticity.