Consciousness: The Ghost in the Machine

A neuroscientific and philosophical exploration into the nature of consciousness, raising the fundamental question of whether consciousness is a product of the brain or exists as a distinct, separate entity.

The warmth of sunlight on your face, the ache of nostalgia, the vibrant, ineffable beauty of the colour green – these private, intimate experiences are known as qualia. Everything you experience possesses a distinct phenomenological character; there is a specific way it feels to undergo an experience, which cannot be explained solely by its physical qualities. 

Together, these qualia intertwine to create the invisible stage upon which our entire reality unfolds, weaving together the subjective texture of existence – our consciousness. Without qualia, human consciousness would be reduced to mere computation: functional, but with no ‘inner light’.

"If consciousness is separate from the brain, how can brain damage so drastically alter the personality, memory, and subsequent qualia of the affected individual? "

The debate on the existence of qualia lies at the heart of the mind-body problem, questioning whether consciousness, and the subsequent subjective experience, is separate from the body, or an emergent property of biological matter. If the mind is truly separate from the brain, their interaction defies physical laws; yet if they are one and the same, we face the ‘Hard Problem’ of explaining how atoms and electricity can produce feelings. 

This article bridges philosophy and neuroscience, seeking to locate the physical substrates of consciousness (if there even are any).

Philosophical Frameworks for Consciousness

1) Cartesian Dualism

First, consider the idea that consciousness is separate from the brain. This is known as Cartesian dualism, which posits that the mind and the body are separate properties. Intuitively, this idea has a significant limitation:

If consciousness is separate from the brain, how can brain damage so drastically alter the personality, memory, and subsequent qualia of the affected individual? 

There is evidence that this ‘self’ is not spared after brain trauma. As neuroscientist Antonio Damasio explains in Descartes’ Error, damage to the brain does not simply inhibit emotional expression, but can erase the subjective experience of emotion itself. His famous case study, ‘Elliot’, suffered from damage to the ventromedial prefrontal cortex. While he could recall the details of tragic events in his life, he was stripped of the emotional qualia that should accompany those memories. He became a dispassionate observer of his own life; he knew when something was upsetting, but he could not feel it. 

If qualia were properties of an immaterial mind, this subjective internal landscape should remain intact despite physical injury. Instead, the damage to the brain results in the erasure of the subjective feeling of experience, implying that even the most ineffable textures of consciousness are still, to some extent, tied to the brain. Therefore, a true separation between mind and body appears improbable.

2) Materialism (Physicalism)

Now, consider the notion that consciousness is part of the brain. This idea, known as materialism, claims that all phenomena, including consciousness, can be explained in physical terms. According to materialists, consciousness is a product of brain states and processes that are ultimately physical. This theory has one major limitation: How can an objective brain provide qualia?

Neuroscience can map the mechanics of vision, but it cannot define the subjective experience of the greenness of green. This leads to the Philosophical Zombie thought experiment. A philosophical zombie is a hypothetical being, identical to a human in every conceivable way, but lacking any conscious experience. 

"(...) there is something about consciousness that physical descriptions fail to account for."

How is that possible, if consciousness is simply a product of the brain? Surely, if materialism is true, it would be impossible for the philosophical zombie to exist without any conscious experience. Logically, if your conscious state is the same as or produced by your physical state, then it is impossible for one to exist without the other.

If we can conceive of a being that has the same neurons firing but no consciousness, it suggests there is something about consciousness that physical descriptions fail to account for. Current neuroimaging techniques, such as fMRI, can demonstrate physical correlations – for example, increased sweat secretion when someone is nervous for an exam – but they are unable to reveal the subjective feeling or emotional experience itself.

The Search for Consciousness in Neuroscience

Neural Correlates of Consciousness (NCC)

The quest to locate consciousness has evolved from ancient Greek philosophy to the modern search for the neural correlates of consciousness (NCC) - brain activity that can be causally related to consciousness. 

There is substantial literature debating the existence of NCCs. For example, extensive reviews of lesion and neuroimaging studies suggest that consciousness is generated in a ‘posterior hot zone’ comprising the parietal, occipital, and temporal lobes. Proponents support this by claiming that electrical stimulation of these brain regions triggers specific subjective sensations. However, others challenge the validity of this research entirely. For instance, Noë & Thompson (2004) argue that NCC research only identifies correlation, not causation. A correlation can explain the where, but not the why of subjective feeling. 

Neuroscientific Consensus for Consciousness

Francis Crick, one of the scientists who discovered the DNA double helix, famously expressed this reductionist view in his book The Astonishing Hypothesis:

"You, your joys and your sorrows, your memories and your ambitions, your sense of personal identity and free will, are in fact no more than the behaviour of a vast assembly of nerve cells and their associated molecules."

Scientists are told to prioritise rationality and empirical evidence over sentiment. In this regard, Crick is rational; we must accept that the brain is the machine that drives the mind. However, this reductionist assertion suffers from a significant blind spot. While we can attribute the mechanics of memory to brain activity, strictly defining meaningful human milestones as no more than biochemical reactions is scientifically plausible, yet unsatisfying. 

To claim that a painting is no more than pigments on canvas is scientifically accurate, but it misses the point of art and human creation. Similarly, accepting that consciousness is merely a biological product need not devalue it. We must not reject the emotional weight of human achievement. The biological explanation fails to account for the private, intimate nature of individual experience. 

We find ourselves at an impasse: there is currently no way to prove consciousness exists independently of the brain, yet strict materialism cannot fully explain why these biological processes feel the way they do. Until we bridge that gap, we must respect the machinery of the brain without dismissing the ghost that inhabits it. 

So, what is consciousness? The short answer is – no one really knows.

References:

1. Blackmore, S.J. and Oxford University Press (2005). Consciousness : a very short introduction. Oxford: Oxford University Press, Cop.

2. Crick, F. (1994). The Astonishing Hypothesis : The Scientific Search for the Soul. New York: Simon & Schuster.

3. Damasio, A.R. (1994). Descartes Error: Emotion, Reason and the Human Brain. London: Vintage Books.

4. Kirk, R. (2019). Zombies (Stanford Encyclopedia of Philosophy). [online] Stanford.edu. Available at: https://plato.stanford.edu/entries/zombies/.

5. Koestler, A. (1968). The Ghost in the Machine. Hutchinson.

6. Tye, M. (1997). Qualia. [online] Stanford.edu. Available at: https://plato.stanford.edu/entries/qualia/#QuaExpGap.

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This article was written by Elwyne Noa Lai and edited by Julia Dabrowska, with graphics produced by Saba Keshan. If you enjoyed this article, be the first to be notified about new posts by signing up to become a WiNUK member (top right of this page)! Interested in writing for WiNUK yourself? Contact us through the blog page and the editors will be in touch.