Psychology has made incredible advances towards the understanding of the human brain. Developments in technology have mapped the structures of the brain in detail. With this progress, some believe that research into neuroscience is closing in on an understanding of the origin of human consciousness. The answer to this age-old question has long been contested, with none of the contrasting explanations fully concluding the argument. The belief is that neuroscience has finally provided evidence for the dominant Materialist theory. However, supporters of alternative arguments, such as Cartesian Dualism, believe that there are aspects of consciousness that will never be explained using conventional scientific methods. More recently, interesting research has been produced that may support the idea of Panpsychism. This essay will examine these arguments and conclude whether neuroscience can be used to explain human consciousness.
Whilst neuroscience is a relatively new field, Materialism, the belief that all that exists must come from matter, and how it is arranged, has been around for a long time. To Materialists, such as Thomas Hobbes (1588–1679), all phenomena that seem mysterious, including consciousness, are fully explainable using science and can be measured with sophisticated equipment. This contrasts to other theories that were suggested around the same time, such as Descartes’ idea of Dualism (1596 – 1650), which posits that the mind exists on a separate realm of existence to the physical one. Materialists, however, argue that if the mind is able to influence the physical world, it must somehow exist within it. Since the 1700’s we have seen the naturalisation of biology as a whole. Life itself was once considered a mystery that was impossible to explain without a magical “vital force” that drove the formation of life. Yet, we now understand many aspects of how life is formed, such as how amino acids form the building blocks of life. The naturalisation of biology has led to explanations of complex systems, such as the visual system, without needing to rely on a mysterious force to account for unexplained phenomenon. Similarly, whilst our scientific understanding of the mind is currently limited, the mystery of consciousness may soon become explainable. Fischer et al (2016) claim advancements have already been made in this area. Voxel-based lesion symptom mapping was used to compare 12 coma-causing brain stem lesions to 24 control lesions. An area within the brainstem known as the “pontine tegmentum” was identified, which significantly correlated to incidences of comas. Ten of the unconscious patients had damage in this area, compared to only one of the conscious patients. Two areas in the cortex, the anterior insula and the anterior cingulate cortex, were found to be linked to the rostral dorsolateral pontine tegmentum. Both of these areas have previously been associated with conscious experience in terms of arousal and awareness in past studies (Medford & Critchley, 2010). These areas may work together to produce the conscious experience. By focusing on the regions involved in maintaining the conscious awake state, it may one day be possible to wake those in a vegetative state. This would signify a major leap forward in the neuroscientific understanding of consciousness if put into practice, but further studies must be conducted to make such conclusions.
However, Gottfried Wilhelm Leibniz (1646 – 1716) suggested even a complete understanding of the mechanisms of the brain could not explain consciousness in it’s entirety. In one thought experiment, he imagined the brain increasing in size until it was comparable to a mill, allowing a person to walk around, observing the machinery inside. Would it be possible to observe the process of a thought coming into creation? Using this analogy, Leibniz demonstrates that the materialist argument cannot possibly account for the subjective aspects of consciousness, as it provides no explanation as to how unconscious material can become conscious. So far, whilst we may be able to measure aspects of brain activity, such asobserving which parts of the brain are most active through fMRI scans, a thought itself cannot be objectively measured.
Chalmers (1995) describes the “hard problem” of consciousness: the difficulty in explaining the relationship between subjective experience and the objective reality it exists within. As Chalmer’s points out, the systems that have developed to allow an organism to operate and survive could easily exist “in the dark”, without any conscious inner experience. For example, science now has a well developed understanding of the visual system, and that when electromagnetic waveforms impinge on a retina and are categorised and discriminated, the colour red may be perceived. Yet, even with this understanding, we struggle to explain the processes that create the experience of perceiving a colour.
Phenomenology is the study of the “inner experience” from the first-person perspective. The term “Qualia” is used to describe the distinctive subjective character of mental states – what it is like to be something. Phenomenologists argue that for something to be conscious, it must have qualia to be able to have a subjective experience. This includes all thoughts, emotions and inner sensations. A rock cannot be conscious as it is not like anything to be a rock, since it cannot experience sensations. Yet, an insect must be conscious to some degree as it is able to sense, and therefore have an inner experience. Using this explanation of consciousness, it is difficult to scientifically prove qualia exist, yet equally difficult to deny their existence, as every human experiences them. Nagel (1974) argues that qualia, and therefore conscious experience, will never be fully explained using scientific methods. The “Umwelt”, the world as it is perceived by an organism, exists on a continuum from easy to imagine, to impossible to imagine. Nagel uses the Umwelt of bats as an example. Bats use sound as their primary sense, for both communication and orientation. By sending out a high pitch frequency that reflects off nearby surfaces, a bat can create a detailed mental image of the surrounding world. This is in stark contrast to how humans primarily navigate using visual information. For this reason, we may be able to faintly imagine what it is like to be a bat, but we never never truly know what it is like to be a bat. Even with major advances in neuroscience, we are no closer than 100 years ago in being able to subjectively experience the Umwelt of another organism.
For Nagel, the problem is in identification. Whilst the sentence “consciousness is matter” may sound correct, it is very difficult to make sense of, as there is no convergence of referential paths. We may have an understanding of both matter and consciousness, but the background information and context required to understand the link between the two is currently too limited. Therefore something is missing from the materialist argument in making this connection. Dennett (2001), on the other hand, suggests that the intuition that an element is missing from this explanation is nothing more than an intuition. He argues from a functionalist perspective, that the brain is comparable to a high powered biological computer, and that just like with a computer, by understanding it’s mechanisms, you can understand how it works. Dennett proposes the idea of creating a human that is anatomically and biologically similar to any other human, but did not contain consciousness. To Dennett, this being would be no different to any other human, and would therefore be no more or no less conscious. The “zombic hunch”, the feeling that there is a real difference between a conscious person and a “zombie” is no different to the cognitive dissonance felt when acknowledging that the Earth is in constant movement, yet not being able to directly perceive it. Dennett believed that this is what Chalmer’s was feeling when he wondered why information isn’t processed “in the dark”. If Dennett is to be believed, then we already have a well developed neuroscientific understanding of consciousness and further progress will be made through further research into the workings of the brain.
Chomsky (2009) divides levels of understanding into two categories: problems, which can be solved and understood, and mysteries, which will never be truly understood. Just as Galileo first tried to understand physics from a mechanical perspective in accordance to the technology at the time, eventually giving up because it was too inadequate an explanation, modern science may have hit a barrier in trying to explain the subjective aspects of consciousness from a purely objective view, such as comparing the brain to a computer. Chomsky suggests that perhaps there is some information that is simply beyond the human capability of understanding. Therefore, like Galileo, the focus of neuroscience should move from trying to create an all-encompassing theory of consciousness, towards providing the best theoretical account of specific phenomena, ergo scientific methods cannot be used to fully explain consciousness.
Another issue may lie in the assumption that consciousness “emerges” from matter. As of yet, no theory seems to be able to explain how consciousness is created. Panpsychists, such as Baruch Spinoza (1632 – 1677), proposed that consciousness may be related to, or a property of, matter itself. Hunt and Schooler (2019) propose a question: how far down the evolutionary tree must one go before a line can be drawn to confidently say consciousness does not exist before this point? Is a single-celled organism conscious? According to the Materialist understanding of consciousness, a line must be drawn somewhere, yet none are able to identify where it must be. To the panpsychist, however, such a line cannot be drawn. Even the smallest division of matter contains a degree of consciousness. Hunt and Schooler suggest that more complex organisation of matter allows for more complex forms of consciousness, as an answer to the “combination problem” of how smaller conscious organisms combine into a singular conscious organism. The proposal of General Resonance Theory (GRT) is that resonance allows the transfer of such information. Previous studies, such as Crick and Koch (1990), have found measures of consciousness to correlate with certain kinds of neural synchrony. Neural oscillation creates brainwaves, such as Gamma waves, which have been correlated with conscious activity. The synchronisation of oscillations across neurones allows the quick transfer of information by creating an electromagnetic field, which Hunter and Schooler suggest is the “seat” of conscious awareness. As this gamma wave moves across the brain, other neurones begin to synchronise to the same frequency, allowing a faster and more connected flow of information. As it moves away from the neurones, they quickly return to their previous resonance of a more localised pattern. By demonstrating the mechanisms that allow the sharing of information quickly across individual neurons, allowing single cells to become part of a single conscious organism, it provides an explanation of consciousness that is plausible given our current knowledge of neuroscience. Unlike other theories that contrast with Materialism, it provides testable hypothesis, for example, if the combination of consciousness requires shared resonance, then similar types of resonance should be found in conscious states, but not unconscious ones. It also provides an answer to Dennett’s idea of the philosophical zombie, suggesting that it would indeed be conscious as long it’s brain contained the necessary mechanisms for neuronal resonance. By fitting in the current framework of neuroscience, whilst taking the findings a bit further, new ideas have been contributed that could be used to interpret future findings in a novel way.
In conclusion, neuroscience has contributed major advancements in the understanding of consciousness. Certain aspects of consciousness, such as awareness, correlate with specific areas of the brain, such as the pontine tegmentum. In doing so, Fischer et al have helped demonstrate what mechanisms are related to consciousness, which may show how consciousness is produced. Therefore, it seems hard to deny success of neuroscience in developing an explanation of consciousness. However, as Chomsky points out, we may have hit a wall in our understanding, with certain aspects of consciousness, such as the Umwelt and qualia an organism experiences, remaining largely unexplained by science. Perhaps Nagel’s suggestion of the background information on both matter and mind being too limited is true, in the sense that the Materialist perspective is missing crucial information to link the two together. Panpsychism and GRT attempt to partially address this problem by using scientific findings to build a model that demonstrates how consciousness increases with complexity as the complexity of matter increases. This model is relatively new and further studies are necessary to test the predictions of the theory, but if such evidence is provided, the theory could act as a unifying model to link our scientific understanding of the brain to the subjective aspects of consciousness.
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The Monkey and The Machine 