Knowing the latest advances in neuroscience can be fascinating and disheartening. Until a little more than a century ago, the French philosopher Rene Descartes, who separated body and mind, was hardly questioned. In that world, mental illnesses were moral defects and freedom or conscience depended on our will or God's will, but not on the way in which the brains were organized inside the skull. Subsequent experience has shown to what extent we are slaves to matter.
One of the cases that prove it is that of Phineas Gage, an American railway worker who survived an accident in which an iron bar pierced his brain. His companions rejoiced at the unlikely return of that competent and kind companion, but they soon realized that he was no longer the same. He stopped arriving on time to work and became aggressive and impatient. The damage he had suffered in the frontal lobe, a region that allows emotions to be managed or planned, had made old Gage disappear forever.
After that case, it has been observed on many occasions that damage to areas of the brain important to process emotions can condemn the sufferer to paralysis. In spite of keeping the reasoning capacity intact, these people can not choose. Plato wanted to organize a society in which the philosophers sent, based on their perfect reason and objective criteria, but did not know how the human brain actually works. As Johnatan Haidt explains in The mind of the righteousWhen a position is adopted, particularly one that involves our morality, it is emotions that push us in one direction. Afterwards, the reason is responsible for justifying a decision that the guts have already taken.
Disorders such as schizophrenia or autism can raise inhibitions and reveal artistic abilities
The understanding of brain disorders is helping us to understand ourselves better and that, in part, is the latest book by Nobel Laureate Eric Kandel, The new biology of the mind. The professor at Columbia University (USA), one of the most prominent neuroscientists in the world, remembers the time when Emil Kraepelin laid the foundations of modern psychiatry seeking the biological origin of diseases of the mind. In those times, when an autopsy was performed it was not possible to identify the physical damage that had caused schizophrenia or depression, but that has changed with imaging techniques and genetic analysis.
"Despite how prodigious it seems, the brain is an organ of the body and like all biological structures is composed of genes that regulate it," writes Kandel. The study of identical twins shows the great genetic predisposition of the main psychiatric diseases. If one of the siblings has autism, the other will have it in 90% of cases, in 70% in the case of bipolar disorder and in 50% in schizophrenia. However, as Kandel himself acknowledges, there is still much to identify the genes involved and know their role and their interactions with the environment.
From the first efforts of Kraepelin, the study of damaged brains has illuminated the knowledge about the healthy and has also shown the narrow margin that separates them from each other. The effective drugs to treat schizophrenia, limiting the excess of dopamine that causes this disease, produce symptoms similar to those of Parkinson's, which has its origin in a lack of the same neurotransmitter.
This game of equilibria is observed with special intensity in the chapter that Kandel dedicates to the relationship between brain disorders and art. Inhibitions as well as abilities are as important to living well, but when the disease appears, repressed artistic instincts can also be released. However, Kandel points out that the idea that creativity is related to mental illness is a romantic fallacy. Psychosis does not generate artistic talent, but it can release faculties blocked by the inhibitions of social and educational conventions. Creativity has a price paid by many artists, as studies have shown that up to 50% of them suffer from some type of mood disorder, be it depression or bipolar disorder.
It is difficult to get rid of the illusion of being free and for that reason at times the walk offered by Kandel for the last century of neuroscientific advances can cause distress. A wound in the brain can make our previous self disappear and medical treatment change something as central to our identity as sexual preferences. Girls with congenital adrenal hyperplasia are exposed to excess testosterone during pregnancy and that experience changes their subsequent gender behavior. On average they usually prefer objects and games typical of children of their age and among those that are medicated to treat hyperplasia there is a small but significant increase in homosexual and bisexual orientation. "We now know that gender identity has a biological basis and that it can differ from anatomical sex during prenatal development," Kandel writes.
The neuroscientist proposes the study of the mind as the pillar of a new humanism, "that combines the sciences, which deal with the natural world, with the humanities, which deal with the meaning of human experience." This humanism reminds us that our mind arises from matter, but points out that this matter can be modified by experiences that could be described as spiritual. Psychological therapies, a conversation at the end of the day, can change the connections between neurons and transform us as a physical intervention.
Kandel speaks in his book of the limitations that biology imposes on human beings, which in that they are not different from the rest of animals. But on this trip to the intricacies of the brain, he reminds us that limitations are also possibilities for that machine.