Descartes’ Error
I can’t remember why, back in 1995, I bought a copy of Antonio Damasio’s book, Descartes’ Error. Was it the cover, with a Renaissance-style portrait overlain with symbols, geometric constructions, and a strange dark block obscuring the eyes? Was it the subtitle – Emotion, Reason and the Human Brain – that caught my attention? While I would like to think that it was the content, which addresses how the social mind affects and shapes rational analysis and behaviour, I suspect it was because it opened with a discussion of Phineas gage. Gage was a blue-collar worker man, employed in the building of a railroad, who had an iron tamping bar explode into his skull, entering from below his cheek and exiting through the top of his head. Remarkably, he survived the accident, with the result that he was to become one of the most famous cases in the history of brains and behaviour.
The story of Phineas Gage is quite extraordinary. He was working as the foreman of a railway gang in the summer of 1848, employed to construct a new railway line in Vermont. His key responsibility was to insert an ‘ex[plosive powder’ into each hole drilled by the team, so that the rock along the intended line could be destroyed. Momentarily distracted when tamping down the powder, he knocks his iron tool against the rock, and the resulting spark immediately creates an explosion, shooting the tamping iron into the air. Gage wasn’t killed but is thrown backwards as the iron bar leaves through the top of his head. After a few ‘convulsive motions’, he sits up, speaks to the people around him and then sits upright in the cart that took him to be seen by a doctor.
The top of Gage’s skull has been blown off, and his brain can be seen pulsing within his skull. That tamping iron was three feet seven inches long (a little over a metre) and weighed thirteen and a quarter pounds. That he survived is almost impossible to believe. He was to experience a fever from the infection of the site, but within two months he is fully recovered, physically recovered, that is. He regained his strength, and could use his senses, with the exception of his left eye, which was damaged in the accident.
However, the psychological changes were profound. Prior to the accident, Gage had been considered ‘”temperate of character”, shrewd, smart and very diligent. After, he was transformed, and the physician’s report noted he was now “fitful, irreverent, indulging at times in the grossest profanity which was not previously his custom, manifesting but little deference for his fellows, impatient of restraint or advice … at times pertinaciously obstinate , yet capricious and vacillating … a child in his intellectual capacity and manifestations, he has the animal passions of a strong man”.
Sadly, the rest of his life was a spiral downwards. He worked for a while on farms, and then became an attraction in a circus. He left that life to work with horses in South America, and eventually returned to California in 1960 to live with his mother. He began to experience seizures, and died in 1861, just 38 years old. While physically it seems he largely recovered from his accident, Phineas Gage was no longer the individual he had been before his accident: we would say he was a ‘different person’. Indeed it is the relationship between his recovery from the bodily consequences of the accident and the change in his personality that was to make him such an important figure in conjectures about the role of the mind, and the reciprocal impact of the brain on the body. Important in the sense that the aftermath of his accident was to lead to changes that were hard to understand at the time, and which remain a puzzle today.
Such an extraordinary case could not be taken much further at the time, as Gage was buried in 1861, without an autopsy. However, it was Damasio’s sister, Hanna, who was to undertake a brilliant reconstruction of the accident, using Gage’s skull. By painstaking reconstruction of the remains, working with a number of collaborators, she was able to show that it was almost certain that it was selective damage in the prefrontal cortices of Gage’s brain that had compromised “his ability to plan for the future, to conduct himself according to the rules he had previously learnt, and to decide on the courses of action that ultimately would be the most advantageous to his survival” (page 33 of Descartes’ Error).
Damasio was then to have a second case to examine, but now a contemporary one. This was the case of Elliot, a man in his thirties, who had been referred for study as the result of a ‘radical change of personality’. Elliot had been an intelligent, skilled and able bodied man, and when Damasio saw him had an excellent memory about the world, and had kept his considerable business skills. However, he had begun to lose concentration at work, and also his sense of responsibility. This was diagnosed as the result of a rapidly growing frontal lobe tumour. Surgery was required, and as a result he had the tumour removed, as well as frontal lobe tissue.
After surgery his skills and use of language was unchanged. However, his personality was completely different. He needed continuing prompting, to get up, to go to work, to keep working. He could no longer follow a schedule, and he would easily slip from one activity to another without completing either. He could understand the material and tasks he was given, but would change to something else almost on a whim. He lost his job, and tried various foolish and unsuccessful ventures. He commenced a series of marriages and divorces. Damasio describes him as a new Phineas Gage “fallen from social grace, unable to reason and decide in ways conducive to the maintenance and betterment of himself and his family, no longer capable of succeeding as an independent human being.” As had been likely with Gage, it was clear that in Elliot’s case parts of his frontal lobe were removed, but no other part of is brain. It was as if he had “a new mind”. In time, Damasio concluded that his intellectual abilities were undamaged, but his responses had changed, and he was experiencing reduced emotions and feelings. He was ‘another Phineas Gage’.
Antonio Damasio is a Portuguese neuroscientist. His interests are n neurobiology, especially the neural systems which underlie emotion, decision-making, memory, language and consciousness. He has developed what he calls the ‘somatic marker hypothesis’ a theory about how emotions and their biological underpinnings are involved in decision-making (both positively and negatively, and often non-consciously). Central to his approach is the view that emotions provide the basic scaffolding for social cognition and the self-processes which underpin consciousness. His approach offers a scientific basis for the linkage between feelings and the body, offering evidence showing the connection between mind and nerve cells … what he calls the “personalized embodiment of mind.”.
It has been groundbreaking work. Current work on the biology of moral decisions, neuro-economics and social communication have drawn on his work. He has proposed that our emotions and feelings as a read-out of body states. In a later book, The Feeling of What Happens, he laid the foundations of what he describes as the “enchainment of precedences”: “the nonconscious neural signalling of an individual organism begets the protoself which permits core self and core consciousness, which allow for an autobiographical self, which permits extended consciousness. At the end of the chain, extended consciousness permits conscience (271-271, The Feeling of What Happens).
His work is complex and challenging, but the implications of his approach are clear. It’s a reflection on Descartes (and hence the title of the book). Descartes based his philosophy using a single first principle: he thinks., best known as the statement ‘Cogito, ergo sum” (I think, therefore I am). Central to this perspective was the notion of doubt: Descartes concluded, if he doubted, then something or someone must be doing the doubting; therefore, the very fact that he doubted proved his existence. “The simple meaning of the phrase is that if one is skeptical of existence, that is in and of itself proof that he does exist.” (Principles of Philosophy, Part IX). Descartes concludes that he can be certain that he exists because he thinks. But in what form? He perceives his body through the use of the senses; however, he comments that evidence suggests that the senses are unreliable. Given this, the only knowledge on which we can rely is through thinking. Thinking is seen as every activity of a person of which the person is immediately conscious
Damasio’s approach upsets that apple cart. We are a long way past Descartes’ musings (well, perhaps I should say his philosophical explorations). Today many want to argue that we are simply data processing machines, AI systems, with our bodies the equivalent of electrical power generators. In that perspective, ‘mind’ is something to be explained away, a peripheral and rather uninteresting phenomenon. It’s a dull and dehumanising view. Indeed, it reflects an even broader understanding, the depressing expectation that soon we will be able to explain humanity, life on earth, and even the secrets of the cosmos at both the level of elementary particles and the cosmos as a whole. Once the view of the world was it was turtles all the way down; now it’s AI all the way up!
If Damasio’s views are subtle and complex, they make a reassuring contrast to those of some scientists who claim that new discoveries have proved free will is an illusion. In large part, this is an argument about genetics. If Damasio offers and nuanced and complex view, there are others who take a far simpler approach, suggesting that many of our traits are more than 50% inherited, including obedience to authority, vulnerability to stress, and risk-seeking. Researchers have even suggested that when it comes to issues such as religion and politics, our choices are much more determined by our genes than we think.
Many find this disturbing. The idea that unconscious biological forces drive our beliefs and actions would seem to pose a real threat to our free will. We like to think that we make choices on the basis of our own conscious deliberations. But isn’t all that thinking things over irrelevant if our final decision was already written in our genetic code? And doesn’t the whole edifice of personal responsibility collapse if we accept that “my genes made me do it”? One source of insight on this comes from the experiences of identical twins.
When Professor Tim Spector started his research on identical twins in the early 1990s, he soon was able to confirm that identical twins were always more similar than brothers or sisters or non-identical twins. As he collected the evidence, his research was undertaken around the time of an emerging consensus was that genes were an important determinant of who we were, a view promoted by advocates like Richard Dawkins. His research was also being built up at around the time of the launch in 1990 of Human Genome Project, setting out to map the complete sequence of human DNA. This was a decade of optimism, when Daniel Koshland, then editor of the prestigious journal Science, captured the mood when he wrote: “The benefits to science of the genome project are clear. Illnesses such as manic depression, Alzheimer’s, schizophrenia, and heart disease are probably all multigenic and even more difficult to unravel than cystic fibrosis. Yet these diseases are at the root of many current societal problems.” Genes would help us uncover the secrets of all kinds of ills, from the psychological to the physical.
By 2000, genes were no longer regarded as the key to understanding health, but they had become the key to unlock almost all the puzzles of human development and illnesses. For just about every aspect of life – criminality, fidelity, political persuasion, religious belief – scientists were writing papers to claim to how genes were the cause of what was being observed. Perhaps the ‘high spot’ in this came in 2005 in Hall County, Georgia, when Stephen Mobley sought to avoid execution on the grounds his murder of a Domino’s pizza store manager was the result of a mutation in the monoamine oxidase A (MAOA) gene. While the judge Refused his appeal, the idea that the low-MAOA gene is a major cause of violence has become widely accepted, and it is now commonly called the “warrior gene”.
In recent years, belief that genes are basis for explaining almost everything about human development and behaviour has waned. In part this is because continuing research has revealed almost all inherited features or traits are the products of complex interactions of numerous genes. However, the fact that there is no one genetic trigger has not by itself undermined the claim that many of our deepest character traits, dispositions and even opinions are genetically determined. (This worry is only slightly tempered by what we are learning about epigenetics, which shows how many inherited traits only get “switched on” in certain environments. The reason this doesn’t remove all fears is that most of this switching on and off occurs very early in life – either in utero or in early childhood.)
In more recent years, Spector’s work has focussed on heritability. We are often told that many traits are highly heritable: happiness, for instance, is around 50% heritable. What does that mean? It is easy to assume that if, for example, autism is 90% heritable, then 90% of autistic people got the condition from their parents. But heritability is not about “chance or risk of passing it on”, says Spector. “It simply means how much of the variation within a given population is down to genes. Crucially, this will be different according to the environment of that population.
Spector spells out what this means with something such as IQ, which has a heritability of 70% on average. “If you go to the US, around Harvard, it’s above 90%.” Why? Because people selected to go there tend to come from middle-class families who have offered their children excellent educational opportunities. Having all been given very similar upbringings, almost all the remaining variation is down to genes. In contrast, if you go to the Detroit suburbs, where deprivation and drug addiction are common, the IQ heritability is “close to 0%”, because the environment is having such a strong effect. In general, Spector believes, “Any change in environment has a much greater effect on IQ than genes,” as it does on almost every human characteristic.
Discounting a simplistic belief in causation by genes has been one significant development in recent years. However, most researchers are still far from catching up with Damasio’s work. If we are now coming to a much better understanding of what complex factors affect the developments and disorders of the body as a physiological system, Damasio’s work on consciousness takes a further step. In suggesting that the roots of conscious are feelings, we are on the edge of confronting some critical puzzles. Damasio suggest three in particular. What are feelings made of? What are feelings the perception of? Finally, and perhaps most important for future research, ‘how far behind feelings can we get’. For me, Damasio is one of the most exciting scientists working on the cutting edge of understanding consciousness.
