Brain Science

I recently read an article about Dr. Vilayanur Ramachandran, an Indian-born behavioral neurologist. This gentleman's approach to certain problems is generally low-tech, stemming from working with few resources in India.

One of the pathologies he devised a simple remedy for, and was at the forefront of the discovery of the cause of, is commonly called "phantom limb," where an amputee patient feels the missing limb as if it were there.

A different scientist working in the early '80s with Macaque monkeys discovered the different areas of the brain that deal with data coming in from the fingers. Then he amputated a finger (I'm not sure about the ethical ramifications about this move, but...), had his lab infiltrated by PETA and was stripped of his monkeys. He got them back years later, and checked the amputee's brain, and saw that the neurons allocated to the finger had been taken over on both sides by the neurons for the two surrounding fingers, like ivy taking over a small gorge.

Dr. Ramachandran noticed in a human amputee patient of his that when you touched certain parts of his face, he could feel it in his amputated arm quite realistically. Turns out the sensory neurons for the face are close enough to hijack good neurons from amputated limbs, but sometimes the brain can still cross itself up, and make you think it's the vacated limb that's delivering sensory data.

Most phantom limb problems are of the nature of pain or a stiffness from being held motionless. How do you fix this? Dr. Ramachandran devised a treatment: let's just cross up the brain ourselves deliberately. What was his expensive fancy sci-fi apparatus? A mirror.

He had his patient put his good arm and his stump onto a table while kneeling on a pillow, so his head was pretty much at the same level as his limbs. Then he put the mirror just in front of the stump and angled in such a way to make it look like his good arm was really his amputated arm. The Doc told him to just look at the mirror image and start doing things with your good hand. 

The patient immediately began to feel that his amputated hand was snapping fingers and counting to five and all the other activities his good hand was doing. They'd successfully crossed up and tricked the brain.

For most patients, this "mirror therapy"--twenty minutes a day for four weeks--tends to diminish the pain completely. Clinical studies at the Walter Reed facility, where amputees coming back from Iraq are stationed, have been positive, though at first everybody was quite skeptical.

One of the other problems this Ramachandran was working on is more bizarre; called apotemnophilia, it is the desire to have a perfectly healthy limb amputated. I'll try to get to the neurology and Ramachandran's low-tech solution to that later.