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Commentary on Phantoms in the Brain

Claire Ceriani's picture

In Phantoms in the Brain, author V.S. Ramachandran, M.D., PH.D describes a number of case studies of neurological phenomena that demonstrate the human mind’s ability to reconstruct reality.  He explains, among many other phenomena, how amputees may develop phantom limbs so well-defined they can “reach out” and “grab” objects, and how the brain fills in images to compensate for blind spots.  Through explaining these unusual situations, Ramachandran also explains how the brains of most people work, filling in missing information and reconstructing reality.  Though he never uses the terms “I-function” or “story-teller,” these are the equivalent concepts discussed in class.

As much of Ramachandran’s research is with phantom limb patients, a number of his case studies are of amputees who experience this phenomenon.  One very different case, however, is that of Mirabelle, a woman born without arms who still experiences phantom limbs.  The phantoms are “functional;” she can gesticulate with her phantom hands while talking.  What is especially interesting is that her phantom arms are much shorter than real arms would have been.  She even asked her prothetist to make her prosthetic arms shorter so they would feel more natural to her.  Ramachandran writes that “To me this was proof that Mirabelle’s phantoms were not wishful thinking.  If she wanted to be like other people, why would she want shorter-than-normal arms?  There must be something going on inside her brain that was giving rise to the vivid phantom experience” (Ramachandran, 41).

This example fits in well with the idea of a story-teller existing in the brain.  Many people argue that the phantom limbs experienced by amputees are just wishful thinking or a vivid type of memory, but then why would someone born without arms still have phantom limbs?  Clearly, the brain has an incredible ability to lie to itself.  Some part of Mirabelle’s brain must know that she does not and has never had arms, but another part knows that she should have arms.  The story-teller in her mind creates phantom limbs that are too short, because it has no blueprint from which it can work.  Mirabelle never had arms, so it cannot simply “remember” her arms.  It must make up its own story, which turns out to be somewhat flawed.  Yet this story is so convincing to Mirabelle that she insists that her arms are gesticulating as she talks, even though she can see that this is impossible.  It is as if she knows that she does not have arms, but simultaneously believes that she does.  Obviously, very different parts of the brain are at work here, one of which blatantly ignores reality.  Is there a part of our own brains that ignores reality and makes up stories as well?  Ramachandran explains that there is.

In another memorable case study, Ramachandran describes Josh who, due to an injury, has a large blind spot in his field of vision.  Ramachandran first explains how the brain fills in missing information in the small blind spot we all have in each eye.  Then he explains the difference in Josh.  Josh’s blind spot is large enough that, when he pays attention, he can actually see the image being filled in.  When looking at a vertical line, broken by his blind spot, he claims that he can see the two halves of the line growing toward each other in his blind spot until he just sees a solid line.  In another test, Josh looked at a column of numbers with 1, 2, and 3 visible above his blind spot, and 7, 8, and 9 visible below it.  His brain completed the column, and he claimed he could see a continuous column of numbers.  But when asked to read them, he could not actually read the numbers in his blind spot.  He said he knew they were numbers, but described them as hieroglyphics.  Ramachandran calls this temporary dyslexia and explains that “Those middle numbers did not exist, were not flashed before his eyes, yet his brain was making up the textural attributes of the number string and completing it” (Ramachandran, 101-102).  Josh’s brain was somehow able to not only fill in simple visual information, such as connecting a line, but to actually fill in textual information.  He knew there should be numbers in that column, so his brain filled it in with numerical information.  He was not able to read the numbers, but he knew they were numbers nonetheless.

This is evidence of the versatility of the story-teller of the I-function discussed so often in class.  Because our blind spots are so small, we do not notice them, and our I-functions are able to fill them in very easily.  But this case study demonstrates how far the I-function will go to fill in missing information.  Even with a very large and noticeable blind spot, it still attempts to fill in information, even if it takes a little longer to do it.  It is even capable of making up numbers, even if other parts of the brain are unable to read the numbers.  Ramachandran fails to explain exactly how this process works, but he does offer several interesting theories about why it works the way it does.  He explains that different parts of the brain are receiving conflicting signals, and that normally, we tend to ignore that difference.  The I-function fills in our blind spots, even though we do not actually see anything there, but because this area is so small, we can easily ignore the discrepancy between seeing something and knowing that we should not be seeing something.  For Josh, his blind spot is much larger, though he often ignores it as well.  He can, however, pay direct attention to it if he thinks about it, more easily than we can because of its size.  When he does pay attention to it, he can actually see the line being filled in.  He can see what he knows to be numbers, but he cannot actually read them.  Now the discrepancy becomes apparent.  One part of his brain is insisting that there should be numbers there and is filling them in.  Another part knows that the eye is not actually seeing numbers there, and so is unable to read any.  This kind of conflict must be going on in our own brains all the time, but we are skilled at ignoring it.  Perhaps if we did not ignore it, we would find it difficult to deal with so much conflicting information.  The stories made up by the I-function are simple explanations that allow us to function in reality without actually perceiving it.

Phantoms in the Brain provides excellent examples of how the I-function reconstructs reality without our ever even noticing it.  Ramachandran offers a number of fascinating theories to explain the many neurological phenomena mentioned in this book, but he never actually states without a doubt how something happens exactly as it does.  This is real science.  When it comes to the brain, there is no way to be certain about why something happens the way it does, because each discovery about the brain reveals new complexities.  The case studies in this book are not meant to be examples of what we already know.  They are meant to make the reader think about his or her own brain and the amazing capabilities it has, even if it is unable to understand itself.

Works Cited
Ramachandran, V.S., M.D., PH.D and Blakeslee, Sandra. (1998). Phantoms in the Brain. New York: HarperCollins Publishers, Inc.