Christian Long

VS Ramachandran: On Your Mind

In TED Talks on May 2, 2010 at 10:42 pm

Reflection by KATHY B.

Original TED page w/ speaker bio, links, comments, etc:

VS Ramachandran:  On Your Mind

This is a very intriguing talk by neuroscientist VS Ramachandran regarding various oddities of the human brain. Dr. Ramachandran discusses three main themes in his talk-a delusion known as Capgras delusion, phantom limbs, and synaesthesia.

Capgras delusion is a lesser-known condition in which a person can recognize someone’s face (as opposed to Capgras syndrome), but they believe it to be an impostor. For example, someone’s mother could walk in the room and the patient would recognize that it looks exactly like their mother, but they would be convinced that it was not actually their mother, but an impostor.

Although I do not know much about the subject, Dr. Ramachandran’s explanation of Capgras delusion seems more sensible to me than does that based on Freudian theory. Whereas Freud would associate the delusion with sexual tendencies, Dr. Ramachandran associates it with a lack of emotional response. He conducted experiments in which he displayed various pictures in front of patients of Capgras delusion and gauged their emotional responses. The pictures were of random inanimate objects, which would not cause an emotional response in anyone, but also of people, such as the patients’ mothers, that, in a person without the delusion, would evoke a response. The patients, however, had no emotional response whatsoever to these images. This caused Dr. Ramachandran to conclude that the reason for Capgras delusion comes from the malfunctioning or miswiring of the section of the brain that causes one to experience emotional reactions to people or things that they have some sort of attraction or connection to.

Phantom limbs were a very fascinating topic to hear about during this talk. These occur when people lose a limb, be it from amputation, in war, or in some other type of accident, and even after the limb is gone they can still feel it there. The patients are cognizant of the fact that the limb is truly not there; they just feel it as a phenomenal sensory experience. Unfortunately, sometimes these phantom limbs can be “paralyzed”, and can be very painful. Dr. Ramachandran believed that the reason for phantom limbs was “learned”; that is, the message that the limb was paralyzed was given to the brain so often that it came to accept it, and thus could not allow it to move.

So how does one help this type of patient?

Dr. VS Ramachandran may have discovered the answer. He gave a patient with a paralyzed phantom limb a box with a mirror, and told him to put the phantom arm on one side of the mirror and the real arm on the other side, in the exact same position. When the patient did this and moved his real arm, he watched in the mirror and it appeared as if the phantom arm was moving. The brain computed this as if the phantom truly was moving, and as a result the pain of the phantom diminished. Dr. Ramachandran allowed this patient to take the mirror box home, and two weeks later the patient called him to report that his phantom was entirely gone. This new technique of helping patients with paralyzed phantom limbs will probably prove to be extremely beneficial to a number of patients in unbearable pain, to the credit of Dr. Ramachandran.

The final phenomenon Dr. Ramachandran discusses is synaesthesia, which is a mingling of the senses. Someone with synaesthesia might, for example, see a color when they see a number, or associate a certain color with a musical tone.

How is this possible?

Scientists found that this is a genetic condition. That means that it results from a mutation in a gene that causes an abnormal cross-wiring of senses in the brain. We are all born with everything wired to everything else in our brain, so if a genetic mutation causes a flaw in the separation of a pair of these, they can remain interconnected, resulting in synaesthesia.

The final thing Dr. VS Ramachandran did in his talk was an amazing demonstration of how we are all really synaesthetes. He showed two shapes, one with sharp edges and corners, and one with soft, round edges. He said that one was named Kiki, and the other was Buba, and asked which people thought which drawing was Kiki or Buba. The result? 99% of people in the audience called the drawing with sharp corners Kiki, and that with rounded edges Buba (myself included). He attributed this to the fact that Kiki sounds sharper, and we therefore associate it with the shape that looks sharper. Similarly, Buba sounds softer and more flowing, so we associated it with the shape that was rounded and “flowing” as well.

Dr. VS Ramachandran is an incredibly brilliant scientist and has made some truly remarkable discoveries in the field of neuroscience. His discoveries, such as that of how to “cure” paralyzed phantom limbs, will lead the way for many scientists in the years to come to find cures, or at least reasons, for various mental illnesses and will undoubtedly benefit many people.

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