From cs240@cs.rochester.edu Tue Nov 4 17:59:43 2003 Date: Tue, 4 Nov 2003 17:57:43 -0500 From: cs240 To: tetreaul@vienna.cs.rochester.edu Jon Weinheimer: Assignment 1

Jon Weinheimer
cs240: Assignment #4
jw010m@mail.rochester.edu
10-10-03

Who Am I?

The question of identity is one that has often been asked and little understood (in the scientific sense of understanding, at least).  When looking to answer the question ^ÓWho am I?^Ô one may resort to many different areas for the answer.  ^ÓI am simply this person, this body.^Ô  ^ÓI am my collection of beliefs and values.^Ô  ^ÓI am the figment created from my memories and experiences.^Ô  All these answers seem perfectly reasonable, however, Dr. V.S. Ramachandran believes that the question ^ÓWho am I?^Ô, as it is currently perceived by most people, cannot truly be answered.  In his book, ^ÓPhantoms in the Brain,^Ô Ramachandran leads the reader through many fascinating neurological cases and experiments that question the nature and existence of a unified self.

Ramachandran^Òs study of phantom limbs provides his first insight into the absence of a unique, unified self.  ^ÓPhantoms in the Brain^Ô contains numerous accounts of amputee patients that claim to still feel and manipulate their phantom limb.  This could simply be explained by a psychological want to still have a limb but Ramachandran provides reasons and examples of it being much more than that.  He claims that since the part of the brain that used to deal with the manipulations of the limb is no longer functional, neurons in the brain have the ability to ^Órewire^Ô themselves to other areas where they can be used.  Other neurologists, like Mriganka Sur, have helped verified this possibility by physically rewiring animals such as ferrets.  This rewiring helps explain the bizarre phenomenon of a man feeling an orgasm in his phantom foot while having sex.  (This phenomenon is not so easily explained through the psychological want to have an orgasm in your foot).  The rewiring of nerves raises some questions about the existence of one^Òs self.  The amputee usually consciously knows that their limb is missing, but the brain continues to ^Ósee^Ô the limb as a part of the body.  These dual images are quite contradictory and yet appear simultaneously as descriptions of one^Òs self.  Ramachandran discusses, in detail, the ability of rewiring and the different consequences it may have.

Another set of simultaneous contradictory descriptions occurs in the discussion of Ramachandran^Òs theory of a ^Ózombie^Ô in the brain.  He relates a story of a woman with a bizarre syndrome that was termed ^Óblindsight.^Ô  The woman in this story suffered damage to a specific pathway in her brain, which left her completely unable to see.  Her condition was unique, however, because when she was asked the orientation of an object or to reach out and grab something, she performed almost perfectly.  Ramachandran provides a logical explanation of this paradoxical occurrence based on the modular nature of the brain.  Without the piece of the brain involved in conscious sight the woman, cannot ^Ósee^Ô an object, but the sight information still reaches the unconscious module of the brain through a different pathway.  This ^Ózombie^Ô allows some actions to be performed without actually experiencing sight.  In one sense, the woman is blind because she does not experience sight, but her ^Ózombie^Ô is able to unconsciously ^Ósee^Ô an object^Òs orientation.  Ramachandran claims that there may be ^Óa multitude of [zombies] inhabiting your brain.  If so, your concept of a single ^ÑI^Ò or ^Ñself^Ò inhabiting your brain may be simply an illusion^Ô (84).

Finally, Ramachandran explains the most bizarre occurrence of simultaneous contradictory images of self with the actions of the limbic system.  Most people feel that emotions play a vital role in their consciousness and their self-image.  The limbic system is the most important part of the brain in the creation, expression, and interpretation of emotions, but what would occur if this system were damaged or entirely destroyed?  One patient Ramachandran describes will not believe that he is actually himself.  In a case with even more damage to the limbic system, a patient may experience Cotard^Òs syndrome and will even refuses to admit that they are alive!  The cause of Cotard^Òs syndrome is not fully explained, but Ramashandran predicts ^Óthat Cotard syndrome patients will have a complete loss of GSR for all external stimuli^Å and this leaves them on an island of emotional desolation, as close as anyone can come to experiencing death^Ô (166).  The possibility of this being merely a psychological issue is refuted by examining normal body reactions.  These patients did not experience the same type of reaction as a normal human when viewing a picture of them.  This is perhaps the most obvious of all possible contradicting images of self.  By all logical definitions of the word, you are very alive but in your own mind, you are indeed dead. 

Despite the serious nature of many of the topics in ^ÓPhantoms in the Brain,^Ô Ramachandran takes a very humorous tone throughout much of his work.  The vast majority of the book revolves around his patients that usually have severe brain damage; however, Ramachandran relates countless humorous anecdotes about the nature and behavior of his patients.  Ramachandran is not making light of the situations or philosophies presented in the book, he uses this tone to make his book readable to audiences that are not extremely familiar with the nervous system.  Although, at times, he does go into detail about the many pathways and circuits in the brain, he balances this with humorous stories of patients believing their arm actually belongs to their brother in Texas.  Because of this humorous tone, the book is still extremely enjoyable for someone with little knowledge of the ins and outs of the visual cortex.

Although it is readable for the average individual, Ramachandran^Òs book is not at all lacking in scientific content.  All the theories he presents are based on his thorough knowledge of the human nervous system.  In addition to neuroscience, his arguments span the fields of psychology, physics, math, and biology.  All this broad scientific material, however, is presented in a clear, understandable manner.  He keeps his discussion of the brain located in the upper levels are the brain structure.  The lower level workings of the brain are not discussed nearly as much as the different pathways and modules of the brain.  This technique keeps the book understandable and reasonable in length while still providing a good basis for understanding his theories and conjectures.  To the scientific mind, this is an important fact to recognize; Ramachandran makes only conjectures rather than claiming to truly prove anything.  At times, he even states that his ideas are mere conjectures that even he only gives 10% chance of being correct, but this does not impede the extreme insight that these conjectures provide about the workings of the human brain.

Although it is not the classic piece of scientific literature, ^ÓPhantoms in the Brain^Ô provides enormous insight and new theories to be studied in neuroscience.  The book was not written to ^Óclose the book^Ô on any topics in neuroscience.  Rather, it provides many new open doors to theories about the brain^Òs complex structures and their interactions.  By examining cases of patients that have portions of their brain missing or damaged, he is able to begin to break down the extreme complexity of the human brain.  ^ÓPhantoms in the Brain^Ô intellectually stimulates the reader so that they too can begin ^Óprobing the mysteries of the human mind^Ô (Front Cover).