Book Review: “Descartes Error” (Part 1)

“Descartes Error: Emotion, Reason, and the Human Brain”
Written by: Antonio Damasio

We spend a considerable amount of time planning for the future. We do our planning within a social context, following rules of social conduct while selecting courses of action most advantageous to personal survival and well – being. Rene Descartes phrase “I think therefore I am” has evolved over time into other phrases which celebrate the mind-body dualism celebrates by Descartes. “It’s all in your mind” and “mind over matter” are just two examples of the idea of dualism extending from academia into everyday life.

In “Descartes Error” Antonio Damasio condenses past thought from Aristotle to modern psychologists and proposes that emotion and rationality are not necessarily at odds. He presents his ideas first and foremost as a neurologist, relying on physiological responses and scientific information to support his position. Descartes “error”, according to Damasio, was to regard emotion as something separate from intellectual activity. Through his observation of patients with brain damage, Damasio became convinced that reason alone is insufficient for the efficient operation of the intellect. Damage to certain brain areas, notably the prefrontal cortex, can leave the patient apparently intellectually unimpaired but incapable of making complex decisions. Such a patient, for example, may understand the factors involved in conducting his business but may keep reaching decisions that are inherently disastrous.

The archetypal example of the effects of prefrontal damage is Phineas Gage. In 1848 New England, Gage suffered an injury in which a tamping rod he was using to compress a blasting charge was blown through his skull by an explosion. The majority of the front part of his brain was destroyed, but he survived and at first glance seemed to be unaffected. However, his personality was profoundly altered; from being a responsible foreman he became reckless and irrational, unable to hold down a job for any length of time.

Another individual studied by Damasio had a brain tumor successfully removed but his frontal lobes were inevitably damaged during the operation. Although his intelligence was unaffected, he could no longer carry on his professional work. He had to be prompted to go to work, and when he got there he might start on one task and persist with it even when it was time to change to something else, or he might spend the whole day pondering how to classify a paper he had just read. Thus he could manage isolated tasks well but couldn’t integrate them into a wider frame of reference. In spite of being confronted with the disastrous consequences of his decisions, he was unable to learn from them.

These patients were apparently more or less intact intellectually but their ability to function as complete human beings was subtly but profoundly impaired. So what is wrong with patients like these? What is missing?

The answer, according to Damasio, is emotional biasing or in other words, desire.

In people with normal brains, their decisions are “weighted” by emotions and this enables them to take decisions quickly according to how they feel. These cases of prefrontal damage hinted at the possibility that certain brain regions may be responsible for the ability to plan future survival within a complex social environment, and that this ability relies upon intact systems underlying both cognition and emotion- this concept is referred to as the “Gage Matrix”. Patients with damaged prefrontal lobes are emotionally bankrupt, unable to determine what choice they desire to make.

The somatic marker hypothesis is Damasio’s explanation of the true processes underlying decision-making. Body states and emotions become associated with certain outcomes, influencing our decisions; this is the hypothesis, briefly stated. Damasio claims that the capability to form and access somatic markers is central to the decision process, and this is why the patients with prefrontal lobe damage show the deficits that they do.

The somatic marker hypothesis derives from the commonly accepted idea that behavior is directed as much as by how we feel as how we think. The concept of the somatic marker is that changes in the peripheral nervous system constitutes a ‘gut’ feeling that helps you make correct choices prior to thinking about that choice. Thus the somatic marker helps you decide upon what course of action to take before you rationally consider what actions to indeed take.

To be continued…