Evan X. Merz Gage's LegacyThe first thing a reader has to realize about Descartes' Error is that in it, Damasio takes on a subject that is largely ignored by the scientific community. He acknowledges this when he writes "emotions and feelings are considered elusive entities, unfit to share the stage with the tangible contents of the thoughts they nonetheless qualify" (159). So a reader has to be prepared to entertain ideas which may seem at odds with much of the scientific community. Though Descartes' Error does have its flaws, Damasio presents a provocative study of how emotions relate to reasoning, and he comes to some intriguing conclusions. He begins with the oft-quoted and tragic tale of Phineas Gage. In 1848, Gage was a railroad worker laying track across the state of Vermont. Unfortunately for Gage, but perhaps fortunately for his legacy, he was traumatically injured when a steel rod traveled through the front of his skull. The bizarre transformation that occurred has been a subject of intrigue since that day. Though Gage was physically healthy, he went from being a friendly, hard-working leader, to being a foul-mouthed, obnoxious loner. This case serves as a spring board for Damasio's book; he observes that Gage was most likely injured in the frontal lobes, and wonders how Gage's case would be handled by modern neurology. The patient who is the centerpiece of the book is referred to simply as Elliot. Elliot was a successful business man, husband, and father until he started getting extraordinary headaches. When his doctors discovered the tumor, his only option was to have it removed surgically. Unfortunately, it was located in a spot nearly exactly where Gage was impailed. After the surgery, Elliot was a different man; he couldn't hold a job, got divorced twice, and made a series of serious financial mistakes. Damasio describes, at great length, how rigorously he tested the functioning of Elliot's brain; Damasio administered nearly every brain functioning examination known to modern science, yet could come up with no test that revealed anything about Elliot's condition. His quandry was simple, "while Elliot's preserved performance was consonant with his superior scoring on conventional tests of memory and intellect, it contrasted sharply with the defective decision-making he exhibited i! n real life" (49). So Damasio's basic goal is to discover the connection between Gage and Elliot, and to do so, he takes a stab at some black subjects of neurology. At this point the book gets a bit off track. Part 2 of the book gets away from patients and experiments and focuses on the process which led Damasio to the formulation of his theory. At very great length, he discusses the anatomy of the brain, brain images, classifications of emotions versus feelings, and evolution. Though much of this serves as a basis for his theory, I found it quite cumbersome and at times, a bit pedantic. Also, much of his theorizing seems based more on intuition and conjecture than on experimental data. The most irksome of his ideas is that of dispositional states. His explanation, though quite-indirectly supported by case studies, seems to dodge the question of how we recall mental images. He reminds us that it is a statistical impossibility for the human brain to store images explicitly, then argues that we store images with dispositional representations. He writes, "Dispositional representations exist as potential patterns of neuron activity in small ensembles of neurons I call 'converge! nce zones'; that is, they consist of a set of neuron firing dispositions within the ensemble" (102). In my interpretation, and I had to read this section many times, he is saying that images don't exist explicitly, but then arguring that they are stored in some sort of encoded form which seems equivalent to an explicit representation. Luckily, a reader doesn't have to accept, or even understand, section 2 in order to enjoy his final conclusions. In the final chapters of the book, he presents his somatic marker hypothesis. In a very cogent manner, he explains his understanding of the connection between emotions and reasoning. The somatic marker theorem states that our minds, at a subconscious level, mark everything we experience with the somatic state which it elicits. So, when a choice presents itself, even before conscious deliberation occurs, our mind runs through the possible outcomes, eliminating or highlighting outcomes based on their supposed somatic markers. He writes, "this covert mechanism would be the source of what we call intuition, the mysterious mechanism by which we arrive at the solution of a problem without reasoning toward it" (188). He concludes that both Gage and Elliot lacked the ability to recall somatic markers, so when they were presented with choices, they would unwittingly make disastrous decisions! Though Damasio can be a bit long-winded, his book is an intriguing journey through the neurology of reasoning. In truth, he touches on many more subjects than could possibly be mentioned in a short review. The broad nature of his work and it's results is both the greatest asset and the greatest weakness of the book. Perhaps though, as Damasio himself hopes, this book will open the doors for other scientists who think that emotion and reason belong to experimenters as well as philosophers. |