I was fortunate enough to experience what neurology is like at the cutting edge recently, when I completed an away rotation in the United States. As should be obvious to anyone, this represented a markedly different practice to the one I usually partake in as a medical student in Africa. But whilst the incomparable economies and educational systems, together with the growing HIV epidemic in sub-Saharan Africa, gives a different flavor to a neurologist’s practice, there are questions at the core of the discipline that are the same everywhere. The most interesting of these relate to the ‘mind-body problem’ in philosophy of mind, and creep into the neurologist’s practice daily.
These questions follow naturally from the fact that most of a neurologist’s time is spent diagnosing, treating, and discussing the plethora of conditions that cause and are caused by damage to the brain. Whether resulting from ischemic, infectious, inflammatory or degenerative processes, the resulting clinical syndromes are both fascinating and depressing. And whereas the distribution of etiologies will differ from country to country, our common anatomy ensures that a similar scope of phenomenology will emerge from different pathologies. Despite the obvious differences between a mother in sub-Sharan Africa whose son is rendered aphasic from tuberculous meningitis, and a father in North America whose daughter’s personality is eroded by a brain tumor, their questions, fears and difficulties can be remarkably similar.
With regards to the resulting philosophical questions, it would seem that we innately1 assume a dualistic position of sorts, taking a viewpoint that’s temporally and spatially unbound to that of our bodies. Haggard2 notes, with regards to our actions, that a “ dualistic view of endogenous causation is engrained in our normal language”. This dualistic language is common amongst patients affected by neurologic illness, as well as their family members. Consider the difference between a statement like ‘my knees aren’t as reliable as they used to be’, and the comparatively absurd ‘my brain isn’t working as well as it used to’. The latter, when considered with anything other than momentary attention, should strike us as bizarre. After all, it has been an endeavor of neuroscience (not to mention other fields like philosophy, cognitive psychology and artificial intelligence) to explain how matter, or the brain in this case, results in the internal environment and our representation of self. The mind, being entirely dependent on the physics constituting the brain, can hardly refer to its constituting parts as ‘not functioning’ without at the same time saying that it is not functioning as it should.
This ‘benign dualism’ does have its advantages. The suspension of the belief that a loved one is nothing but an appropriately arranged constellation of atoms immediately creates a certain sanctity. Problems with the sanctity of human life notwithstanding, it does contribute to a worldview that we all prefer. As Dennett has argued3, the act of treating someone not only as a body, but as a ‘self’ that has a body helps preserve a ‘belief environment’ around things like death and birth, and protects individuals close to those stages. Whilst we might admit that this ‘center of narrative gravity’ is a fiction of sorts, it is a useful construct that informs our day-to-day behavior. Furthermore, viewing people ‘as brains’, or subscribing to a ‘brainhood’ that views people as ‘cerebral subjects’4, opens several philosophical wormholes. Perhaps justifiably, people fear that this view will result in fatalism, where concepts like free will and responsibility will be defunct, resulting in an unavoidable and irrevocable slide towards anarchy.
The issue is most dramatically played out in the legal system5. Here claims of criminality being the result of ‘organic’ pathology bring the issues of free will and responsibility into focus. If sufficient evidence tying someone to a murder is provided, the court has little choice but to find someone guilty and duly sentence them. But what if it is shown that the defendant has a brain tumor disrupting the pathways involved in moral reasoning and inhibition? Suddenly, it’s as if this ‘physical’ reason for the behavior removes the responsibility from the defendant. But surely there are physical processes underlying all of our actions? As neuroimaging improves, deciding where to draw the line will become more complicated.
More commonly, our unwillingness to accept that we are our brains, or at least a subset of thereof, is the reason behind the remarkable interest in cognitive neuroscience, particularly when it involves functional neuroimaging. Rarely a week goes by without a journalist reporting on a specific human quality or ability that has been found to correlate with certain brain regions. We hear of empathy being localized to the anterior cingulate cortex6, of romantic attraction activating the limbic system7 and of deception involving the prefrontal cortex8. But were our position on these things at all altered by these findings? Surely a difference in, for instance, emotional disposition between people would always have been dependent on a difference in brain function? The fact that we now have tools sophisticated enough to show the difference is still impressive, and the research has many interesting implications, but we didn’t discover a new fact about the mind-body problem.
This double-think we all partake in, where we view others and ourselves as being more than matter and physics, yet at the same time acknowledging that we can explain all observed and experienced phenomena in physical terms, lies at the heart of what makes neurology such an interesting and difficult field. In stark contrast to a patient whose heart is failing, the patient suffering from a ‘failing’ brain is suddenly confronted by the abovementioned philosophical conundrums. They can’t help but acknowledge that the illness isn’t just affecting ‘their body’, but that it is affecting ‘them’. As Alcauskas9 notes, neurological illnesses “dehumanize in a way that heart disease and renal failure do not.”
Despite the facetious safety our dualistic positions provide, whereby ‘we’ exist in a dimension unrelated to the mere physics of everything we observe, the neurological patient draws attention to the fragility of our being. A relatively simple physical process, like a clot becoming lodged in a vessel, can remove much of your brain and hence much of you. Your wife can be rendered a stranger, your taste in music may change, you may lose the concept of a ‘left side’. For those unfortunate enough to see their husband slowly change from the loving and caring companion to a paranoid and violent stranger, as may happen with frontotemporal dementia, the innocence and functionality of a dualistic view is unavailable, and insofar as we can provide physiological answers, these are wholly inadequate10. For us as physicians, in the first world just like in the third, these patients provide a constant reminder of the fragile relationship between the deterministic physical processes happening behind our eyes and everything we value.
References
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2. Haggard P. Human volition: towards a neuroscience of will. Nat Rev Neurosci. 2008;9:934-946.
3. Dennett DC. Consciousness Explained, 1st ed. London: Penguin Books; 1993
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10. Adamo A. Of Minds and Maps. Neurology. 2009;72:1364-1365.