The ghost in the machine: Explaining conciousness

By Joe Greenway

René Descartes famously declared in the 17th century that the only thing we can be certain of, is our own existence as a thinking entity: ‘I think therefore I am’ – cogito ergo sum (Descartes, 1641). While the external and physical world around you could well be an illusion, Descartes concludes that you can know for sure of the existence of your thinking mind – your consciousness, because after all, here you are thinking about it.

If you didn’t exist as a conscious, thinking being, then you wouldn’t be able to be here thinking about it – thus the presence of your thoughts about the matter alone, prove your existence. But what actually is consciousness? Generally, most consider consciousness to be this sense of awareness of one’s environment and experiences. That’s more of a descriptive question – the harder question is how do we explain it? The philosopher David Chalmers divided this into two categories: what he called the ‘easy problem’ of consciousness, and then, the ‘hard problem’ of consciousness.

For Chalmers, the easy problem is explaining cognitive functions - and how they arise from physical processes in the brain. In contrast, the hard problem is accounting for why these functions are accompanied by

conscious experience. This includes explaining what philosophers call ‘qualia’ – the properties of experience, such as the redness of a strawberry or the perception of the taste of wine. In terms of sight and colour, for example, the easy problem would be explaining how our visual systems interpret different wavelengths, but the hard problem would be showing how this function can give rise to the sensation of colour. While Chalmers recognizes that many of the easy problems of consciousness may be actually quite difficult and require much arduous work, they are ‘easy’ in comparison to the hard problem of consciousness, as the methodology is already there. The hard problem however, is as elusive and problematic as ever.

The first way to perhaps deal with the ‘hard problem’ and explain the existence of consciousness, would be the perspective of dualism (Descartes, 1641). Although this viewpoint has lost much support in modern time, it’s interesting in its contrast to empirical approaches, and I already mentioned on of its primary advocates earlier: Descartes. Dualism essentially proposes that we are composed of two separate entities: the mind, and the body. The mind is immaterial, and conducts mental events, while the body consists of material substances and conducts physical events.

The yin and yang was a popular depiction of dualism from Ancient Chinese Philos ophy.

For many religions, like Christianity, the existence of an immaterial mind suggests a way to demonstrate their belief in an immortal soul within us. This then raises several difficult questions about the survival of consciousness after death, mainly, does the immaterial mind decay with the material body, or does it continue to exist? But those are problems for another time. Descartes furthers this standard dualism, with his own version: Cartesian dualism. While his scepticism led him to doubt the existence of the physical world

(including his body), his famous maxim ‘I think therefore I am’, meant he could be sure of the existence of his mind – his ‘cogito’. Thus if he is able to be sure of the existence of his mental representation – his mind – but doubtful of his physical representation – his body – then the two must be separate.

Nevertheless, Descartes understood there were connections between mental events, and physical ones, and so, for quite sensible neurophysiological reasons, he concluded that the pineal gland – a structure lying centrally within the brain – would be the place where messages were conducted from the physical body to the mind.

Descartes’ view is neatly summed up by Gilbert Ryle in his book The Concept of Mind, as holding that the human being is a ‘ghost in the machine’ (Ryle, 1941). Events in the machine, the physical body, are like events in the physical world, involving interactions with atoms, electrical fields, forces etc., whereas events in the ghostly part, the mind, are completely different. Despite this there is always a close relationship between the mind (‘the ghost’) and the body (‘the machine’).

Many however, particularly with the emergence of modern science, oppose the theory of dualism, as it delves rather unnaturally into the mystical (Graziano, 2019), and does not fit at all well with empirical science. Most scientists therefore prefer to take a much more materialistic viewpoint (the theory that the only thing that exists is matter) to explain consciousness. They argue that consciousness is an emergent property of the brain, and that once we fully understand the intricate workings of neuronal activity, consciousness will be laid bare. As for the so-called ‘qualia’ – the properties of experiences – well, scientists don’t tend to like that idea either. As Patricia Churchland at the University of California argues: “ ‘Qualia’ is a term of art, introduced by philosophers who want to make questions about the nature of consciousness only answerable by spooky, non-biological accounts.” Some take it even further, attacking the idea of consciousness itself (Ananthaswamy, 2016):

“Consciousness is a user illusion designed by evolution to make life easier for the brain that must guide a body through a perilous life,” says the philosopher, Daniel Dennett. For example, when we see things as a particular colour, the real world isn’t like that, but our visual systems ‘colour-code’ the world around us, to simplify it.

However, this still doesn’t explain how consciousness emerges from the brain – illusion or not (Du Sautoy, 2016). One attempt at researching consciousness has been to look for signatures of it in brain activity. Various brain areas have shown to be active when we are conscious of something, and quiet when we are not. For example, research conducted by the French National Institute of Head and Medical Research, in Gif sur Yvette, identified regions such as the frontal and parietal lobes to be particularly active when we are conscious.

Similarly, Bernard Baars of the Neuroscience Institute of California theorised that non-conscious experiences are processed in specialised local regions such as the visual cortex - we only become conscious of this activity when the network of neurons called ‘the global workspace’ receives the information.

An image showcasing the ‘global workspace’. Cited: fpsyg-04-00200-g001.jpg (686×588) [Internet]. [cited 2022 Feb 16]. Available from: https://www. frontiersin.org/files/Articles/40168/fpsyg-04-00200HTML/image_m/fpsyg-04-00200-g001.jpg

Another idea is to observe the brain when consciousness is absent or reduced, such as when the person is in a vegetative state. Brain scans have shown that people in this condition usually have damage to the thalamus – a relay centre located in the centre of the brain, as well as damage to the connections between the thalamus and the prefrontal cortex – a region at the front of the brain, responsible for high-level complex thought. Additionally, scanning of the brain while a person loses consciousness under general anaesthesia, has again shown a notable reduction in the activity of the lateral prefrontal cortex. Other experiments of this type have also identified the posterior parietal cortex – another region of the brain heavily involved in complex thought – as crucial to consciousness.

These three brain areas – the thalamus, the lateral prefrontal cortex, and the posterior parietal cortex, all share an important feature in humans: they have more connections to each other and everywhere else in the brain, than any other regions. This makes them very well placed to receive, combine and analyse information from other parts of the brain, and neuroscientists believe that it is this bringing together and processing of information that is the distinctive feature of consciousness. Hence some might consider these regions to be almost ‘seats’ of consciousness.

Unfortunately, while these kinds of investigations have been invaluable for narrowing down the search for the parts of the brain involved in consciousness, they don’t do much to explain consciousness itself, but rather the ability to report about consciousness. We are still left with the ever-perplexing problem of ‘qualia’ and the experience of consciousness, for example, what happens in the brain when we see the colour red. As the psychologist Bruce Hood put it: “Even if you measure brainwaves, you can never know exactly what experience they represent.” Similarly, the philosopher Thomas Nagel asked the question ‘What is it like to be a bat?’ (Nagel, 1989) Your response might be to imagine flying around in the dark, seeing the world in the echoes of high-frequency sound. However, this would only give you the impression of what it would be like if you were a bat. Nagel here is emphasising that there is no way of knowing what it is like for a bat to feel like a bat- to truly know what the existence of a bat is like. Furthermore, Nagel argues that even if you knew every detail of the physical workings of a bat’s brain, you would still not know what it is actually like to be a bat. That is the conundrum of consciousness, a quite ‘hard’ problem indeed. While much progress has been made in the ‘search’ for consciousness and scientific attempts to explain it, and it may well be truly uncovered with future scientific research, consciousness remains, in the words of the Stuart Sutherland, ‘a fascinating but elusive phenomenon.’ References:

•(Descartes, 1641), Date: 1641 Retrieved from: Meditations [book] Author: René Descartes •(Ryle, 1941), Date: 1941 Retrieved from: The Concept of Mind [book] Author: Gilbert Ryle •(Graziano, 2019), Date: 2019 Retrieved from: NewScientist (https://www.newscientist.com/article/ mg24332480-000-true-nature-of-consciousness-solving-the-biggest-mystery-of-your-mind/) [online] Author: Michael Graziano •(Ananthaswamy, 2016), Date: 2016 Retrieved from: NewScientist (https://www.newscientist.com/article/ mg23130890-300-metaphysics-special-what-is-consciousness/) [online] Author: Anil Ananthaswamy •(Du Sautoy, 2016), Date: 2016 Retrieved from: What We Cannot Know [book] Author: Marcus Du Sautoy •(Nagel, 1989), Date: 1989 Retrieved from: What Is It Like to Be a Bat? [book] Author: Thomas Nagel