Professor Lappin

Psychology 115A Section 13

October 9, 2000

Damasio and Descartes’ Error

Antonio Damasio, in his book Descartes’ Error: Emotion, Reason, and the Human Brain, stimulates a discussion about how the human mind processes feelings and how those feelings affect the way humans interact with the world. His volume is not meant to provide concrete answers as much as it is intended to be a catalyst for dialogue about the connections between the mental and physical centers of the brain. Although research into the workings of the mind is still in its infancy, it has advanced at an exponential rate during the late decades of the 20^th century. Modern technology allows us to greatly increase the pace of research through the use of magnetic resonance imaging, computerized axial tomography scanning, and other new processes. Science is on the verge of a new frontier of knowledge concerning the mind and the body. Damasio’s book is a beacon of light pointing towards questions science must use its new expertise to answer: Why does our body state affect the way we think and act? Can emotions alone provoke a measurable change in physical properties of the body? How can frontal lobe injuries be prevented, and can such injuries be treated or repaired?

The central dogma of Damasio’s book is that the brain and body are inseparably linked, and cannot be considered to be two distinct organisms. It is critical to understand that not only do the brain and body send and receive signals back and forth, but that parts of the brain separated by many neurons also communicate directly (Damasio 88). It is impossible to separate any part of the brain from the body without having a profoundly negative effect on some part of the organism’s physical or mental functions. Conversely, the loss of a limb from the body does not always prevent the brain from believing that it receives signals from that portion of the body. There are two disorders associated with loss of control of a bodily function. People with phantom-limb condition have physically lost an extremity, yet somehow they insist that they can still feel heat, cold, and pain in the area which is not physically a part of their body anymore. This suggests that although a piece of the body has been destroyed, the corresponding piece of the brain responsible for receiving signals from the nerves in that part of the body can still function normally. A more serious condition occurs when both the body and the part of the brain responsible for visceral signal processing are damaged simultaneously. This condition, called anosognosia, renders a person unable to contemplate the fact that they have been injured (Damasio 62-63). Anosognosics must be constantly reminded that they have been paralyzed, as they can never remember that they cannot move their extremities. The component of the mind responsible for receiving sensation from the body has been destroyed, so the patient’s brain has no way of knowing what has happened to his body. Anosognosia tells us brain damage can affect not only the way we think, but also the way we perceive our physical condition. Descartes made his most significant error when he suggested in his statement "I think, therefore I am" that the body and the brain could ever be thought of independently.

Damasio’s findings are significant because they attempt to answer the questions of how the mind and body interacts while concurrently raising other questions about our knowledge of self. Damasio proposes a "somatic marker hypothesis", in which he postulates that good or bad physical states can cause us to accept or eliminate possible courses of action, respectively, in a much quicker fashion than would be possible with a normal qualitative analysis (Damasio 173). This theory, which he bases upon factual evidence and his own speculation, provides a model for understanding how humans make decisions. One of the major deficiencies seen in patients with damage to the frontal lobes of their brain is that they have trouble making decisions which involve complicated sets of outcomes and consequences. Damasio believes that these people have lost their ability to generate or recognize somatic markers, thus rendering them incapable of detecting the most beneficial in a series of options. The loss of somatic markers renders the afflicted individual nearly incapable of functioning in society. Damasio’s example is that of a frontal lobe patient who could not decide on which of two days to schedule an appointment, even after half an hour’s cogitation (Damasio 193-194). This example and the well-documented struggles of other frontal lobe patients lend credence to Damasio’s theory while simultaneously illustrating the need for more research into this area of science.

It is obvious that more research must be done in the field of neurology, specifically in the area of frontal lobe damage and its resulting effects on emotion and reason. Though Damasio has conducted thorough and excellent research and experimentation, his findings are constrained by the fact that one of his principal case studies dates back to the 19^th century, when the field of medicine and documentation were worlds away from their present efficiency (Damasio 3-7). Unfortunately, science must presently wait for a personal misfortune to bring them a patient with frontal lobe damage to be examined. Hopefully, in the future, we will acquire a groundswell of knowledge about how the different parts of the brain responsible for controlling emotion and reason are connected. Then, assuming that the pace of computer technology continues to advance at or near its current rate, we will be able to generate computer simulations of frontal lobe damage and predict its resultant effects on physical, mental, emotional, and societal well being. As this knowledge is disseminated throughout the world, it may be possible to create a three-dimensional map of the human brain, much as has been done with the human genome. Until that day, however, we must understand that our knowledge about the mind-body connection is rudimentary, and be willing to adapt or scrap existing theories as new evidence presents itself.

It is obvious that Damasio’s book does not take us to a destination; it merely points our compass in the right direction to begin our journey. In other words, science has a long way to go to explain and understand the complexity of the connection between emotion and reason. For instance, the problem of how to treat existing frontal lobe injuries remains largely unsolved. With enough knowledge of the chemical signals between the brain and the body, could medicine synthesize a drug which could partially restore the somatic markers lacking in frontal lobe patients? If our expertise with microscopic surgical instruments increases dramatically, is it conceivable to think that brain surgery could one day become safe and commonplace? Or would special classes designed to help brain-damaged patients better deal with society be the most viable answer? Whatever the answer, Damasio’s insights provide hope that an effective treatment for frontal lobe damage lies on the horizon.

Works Cited