Mind-Brain Identity? Obvious Fact or Logical Fallacy?

One of the most typical unaware premises with which also professional neurologists and philosophers of mind work is what I call the ‘mind-brain-function fallacy’, and from which they jump to the conclusion of what is called the ‘mind-brain identity.’ It can be summarized as follows: since an impairment to our brain structure leads to cognitive impairments, the logical conclusion is that the brain produces those cognitive abilities. Or, rephrasing: since our brain chemistry determines our states of consciousness, it is obvious that the brain produces consciousness.

After all, it is undeniable that there is a direct relation between the physical state of our brains and our subjective experiences. It is quite a common experience how those tiny alcohol molecules, once they get into the blood flow of our brains, can alter our state of awareness. We know that psychedelic drugs can lead to intense subjective effects. Ever heard of dopamine? It is a neurotransmitter – that is, a molecule that enables biochemical transmission among neurons – which is responsible for the effects of a drug like cocaine. If the ‘Broca’s area,’ a left cerebral hemisphere area, is disrupted, one loses the ability to speak (interestingly, however, not the ability to comprehend language). Someone being anesthetized using anesthetic drugs (seemingly) ‘loses’ consciousness. And nowadays, we have a whole bunch of sophisticated brain scan technologies that make it clear, beyond any reasonable doubt, how for every conscious experience, there exists a neural correlate in our brains. With these, one can show how any emotional state is mediated by the ‘limbic system.’ For example, the amygdala, a tiny collection of nuclei about 1 cm across and deep inside the ‘temporal lobe,’ lights up whenever we experience negative emotions like fear, anxiety, or stress. So does the ‘hypothalamus,’ another little portion of the brain, responsible mainly for regulation (such as body temperature, circadian rhythms, etc.) but also containing our emotional reward, fear, and defensive behavior circuits. And what about that wonderful emotion we call ‘love’? Neuroimaging techniques show that, when we are in love, dopamine is released in the brain reward system. Therefore, the narrative goes that love is just a bunch of hormones wreaking havoc with your brain activity – something similar to what cocaine does. Just a neurobiological chemical cocktail that Nature invented to impel us to mate and reproduce. Nothing else.

These were only a few of the many possible examples. Modern neuroscience has written tomes on the correlation between particular physical, emotional, or cognitive functions with specific brain areas. This is what leads many scientists to state that “there is overwhelming evidence that consciousness is generated by the brain”, or that “we know beyond any reasonable doubt that mind is an epiphenomenon of the brain”, etc. This thinking is also reflected in the language and word choice one can observe in the specialized literature, in which one reads statements about how the brain ‘produces,’ ‘generates,’ and ‘creates’ consciousness without feeling it necessary to substantiate such claims.

Therefore, apparently, no place is left for any form of dualism. Mind emerges from matter; there is no distinction. Other alternatives are no longer worthy of further scrutiny. Period.

Sounds rational, doesn’t it? Because it sounds obvious that if from A follows B, always, then A must be the cause of B. Right?

And yet, this sort of reasoning has frequently led to a well-known logical fallacy into which the human mind has fallen over and over throughout the history of science: the belief that correlation implies causation. We tend unconsciously to mix up a correlation of two observed phenomena as proof of one being the cause and the other being the effect.

A down-to-earth example that clarifies this fallacy is the correlation between ice cream sales and sunglasses sold. One doesn’t need to be a rocket scientist to understand how this correlation doesn’t authorize us to conclude that there is any causal relationship. Wearing sunglasses doesn’t make people more willing to buy ice cream.

Consequently, the fact that two events are always temporally coincidental or always happen shortly, one after the other, doesn’t imply that the first event caused the second event to happen. These sorts of logical fallacies are known as ‘post-hoc fallacies’ (from the Latin “post hoc ergo propter hoc”–“after this, therefore because of this”).

This might sound like a ridiculous example, but when one deals with complex systems, things can become much more subtle, even luring very smart people into these sorts of logical fallacies, especially if it confirms their expectations.

The larger and more complex a system is, the harder it becomes to convincingly detect, with certainty, the causes and effects. This is why every good scientist who deals with large data sets has been trained to cover up these false statistical correlations by learning tons of math, applying sophisticated tools of statistical analysis, and always working with a ‘pinch of salt’ before claiming whatever causal relationship.

But the mind-body identification, which links the neural activity as the cause of conscious experience, is the almost unquestioned working premise based on an even subtler level of conflation between correlation and causation. It also escapes to well-trained scientists because it is not of a statistical nature; rather, it is of a more conceptual nature that can easily escape attention, especially if there is an ideological background. The serious and scientifically rigorous cognitive neuroscientist should be agnostic in this regard but, most scientists jump to conclusions and consider this causal relationship to be obvious. They are unaware of their ‘confirmation bias‘ –that is, their desire that some data or empiric evidence supports their beliefs and fits in their worldview.

Good science, however, did not progress by jumping to conclusions. It has always been based on a principle of exclusion of alternative explanations. Serious skepticism is not based on the parsimony of a hypothesis or assuming something to be true or false until proven otherwise, as most so-called ‘skeptics’ tend to do nowadays. Rather, it is based on ruling out that a specific fact or phenomenon can’t be explained otherwise. The habit of correlating neural states and mental states, as the former being the cause of the latter, betrays an unreflective attitude that scientists would not allow in other contexts. It has always been an elementary codex of science that a theory is accepted only when other alternative explanations have been ruled out.

So, what are the alternatives to the mind-brain identification? Can we explain the strict relationship between neural correlates and mental states as the former being the cause of the latter? If so, consider following pertinent correlation-cause fallacies.

In what sense does this reasoning differ from concluding that the eyeglasses-acuity of vision correlation proves that eyeglasses produce vision and, since broken eyeglasses impair vision, then vision must be in the eyeglasses? If a display device, such as a computer monitor, is damaged and does not appropriately represent the data, must we then conclude that the data is in the monitor? Is the fact that, by cutting a tungsten filament of a light bulb leading to the interruption of the electric current flow, evidence for electric energy being generated by the filament? If light can be turned on and off by a light switch, must we conclude that the light is ‘produced’ by the light switch?

Going beyond these analogies, how does this concretely relate to the states of consciousness and our brain states? Let’s take the correlation between the secretion of dopamine and the emotion of love. If we carefully think about it, this is no evidence for love being just a chemical reaction. Also, a flash of light on your eye retina triggers a chemical reaction in the visual cortex, but nobody would argue from that that light is just chemistry in the brain. One might then argue that the chemical origin of love is also documented by its external causation, namely, that by taking some drugs, typically cocaine, one can induce very similar emotions. But, again, with transcranial electrical stimulation of the visual cortex, one can also induce the perception of flashes of light (called ‘phosphenes’): link. It is even possible to induce the visual perception of luminous shapes, such as letter shapes in blind people: link. And, after all, we all know well that we might be seeing stars or light flashes like lightning, just by pressuring or rubbing our eyes (an effect known as ‘photopsia’). But nobody would reduce the existence of real stars, lightning, or the letters you are reading only to chemical reactions in the brain.

So, this line of reasoning does not prove or dismiss much. By applying a bit of critical analysis, it reveals how things are not as simple as the unreflective naturalistic neuro-philosopher would like us to believe. We can equally well sustain the contrary hypothesis: consciousness, mental states, and emotional states determine the physical state of a brain, not the other way around. And, if on particular occasions it seems to go the other way around, this is precisely because the brain is an interface that can attune to it. The brain might be a physical substrate through which these conscious states manifest.

The metaphor most idealists prefer is the ‘radio metaphor’ or ‘filter theory of consciousness,’ which dates back to an original idea of American psychologist William James, who stated: “My thesis is now this: that, when we think of the law that thought is a function of the brain, we are not required to think of productive function only; we are entitled also to consider permissive or transmissive function. And the ordinary psycho-physiologist leaves this out of his account” (emphasis in the original text) [1]. James thought of the brain and consciousness as the prism separating white light into colored beams, respectively. If a broken prism fails in its function to ‘reveal’ the colored light beams, this should not induce us into the logical fallacy that the prism ‘produces’ colored light. It is just an object with a transmissive function; it doesn’t ‘generate’ anything.

The English writer and philosopher Aldous Huxley expressed a similar idea and proposed that the brain is a ‘reducing valve’ of what he called a ‘Mind at Large,’ a universal or cosmic Mind that comprises all of reality with all ideas and all thoughts. According to Huxley our mind filters reality under normal conditions because, otherwise, we would be overwhelmed by the knowledge of this universal Mind. But psychedelic drugs can remove the filter and bring us into contact with the Mind at Large, leading to the experiences that several mystics describe. In his words: “To make survival possible biologically, Mind at Large has to be funneled through the reducing valve of the brain and nervous system.”[2]

Can we consider the brain a material ‘connecting device’, an ‘interface’ or ‘relay station’ between consciousness and mind to the material world? Can the brain eventually be a ‘pre-processor’ of sensory stimuli from the physical world, a sort of ‘physical mind’ which computes these stimuli to be transferred and presented to mind and consciousness, but is not the mind and consciousness itself? What disproves the notion that the brain may not be just a sort of ‘radio station’ that tunes into consciousness and mind? A ‘transceiver’ that transmits information from the physical environment to the mind while receiving the mind’s cognitive orders? In this view, the brain exists physically, as a highly complex physical system, responsible for pre-processing the most material and mechanical sensory information beforehand, but it plays no role in ‘creating’ consciousness.

Or should we dismiss it altogether by resorting to the magic wand of Occam’s razor, which can always rescue our preferred worldview that there is no reason and no need to believe in such silly theories that multiply unnecessary entities and that one should always posit matter as fundamental without questioning and further thought?

Of course, these analogies don’t provide evidence for the opposite claim either, but they make it clear how careful we must be about jumping to metaphysical conclusions driven by our unaware assumptions, our potentially unaware ignorance, and especially our desire to read, in a few facts, an ultimate proof confirming our own ideological preconceptions and personal worldviews. This should hold not only for the materialist but for the dualist, idealist, anti-physicalist, and spiritualist (or whatever we would like to call them) as well. But fact remains that nothing in modern science prevents us from thinking otherwise. We are allowed to conjecture how the physical brain is not the source, origin, or cause of anything but is foremost a tool of perception and reception and a channel of expression. We will also argue that this is not only a viable hypothesis but even the most logical conclusion.

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[1] William James, “Human immortality”, 1898, Houghton, Mifflin and Company, The Riverside Press, Cambridge.
[2] Aldous Huxley, “The Doors of Perecption”, 1954, Chatto and Windus.