Science without technology

The thought of neurological research often conjures up images of state-of-the-art technology such as fMRI machines, powerful microscopes, and sophisticated computer systems.

But V.S. Ramachandran, Director of the Center for Brain and Cognition at the University of California at San Diego , made one of his best-known scientific discoveries using a mirror and a cardboard box.

He was investigating “phantom limb syndrome,” in which patients experience physical sensations in a limb that has been amputated or missing from birth. Some sufferers, for example, feel their missing arm is stiffened into a fixed position, and it is excruciatingly painful, sometimes with the sensation of fingernails digging into the palm of the hand relentlessly. Even though the limb is missing, the pain is quite real, and poses a major challenge to physicians charged with alleviating their patient’s suffering.

Several theories have been put forth to explain this bizarre phenomenon, the most widely accepted of which was the possibility of irritated peripheral nerves (“neuromas”) at the site of the amputation — a theory that Ramachandran disproved using a q-tip. He theorized that the patient may actually be the victim of a type of broken feedback loop.

Consider that as I type this, my brain is telling my fingers to move. Then, as they move, my brain (specifically the “somatosensory cortex”) gets feedback from the nerves in my hands to say “yes, I’m moving.” In phantom limb syndrome, the brain tells the missing limb to move, but receives no feedback of movement. Thus, the brain “learns” that the limb is completely paralyzed and unmoving. Similarly, the brain may tell the hand to clench and make a fist (it may do this to try to gain some sensory feedback which it has noticed is lacking). With no feedback from the hand to say “stop clenching now, that hurts,” the signal continues indefinitely, creating the sensation of digging fingernails.

In order to overcome these painful phantom limb sensations and restore the feedback loop, Ramachandran needed a way to stimulate the brain into thinking that the arm was actually moving. What he did next was both laughably simple and astoundingly ingenious. He took a cardboard box and stood a mirror upright in the centre of the inside of the box. The phantom limb patient could then sit at the box and place his real hand by the mirror, creating the illusion of two hands! Immediately, patients felt their phantom limbs moving, and in many cases their pain was alleviated after just a few sessions with the “mirror box.” The visual signal was enough to tell the brain that the hand was moving, just as if the hand had sent the signal itself.

This treatment has shown much promise and has spurred further investigation in this area. Recently, scientists from the University of Manchester have demonstrated that the use of virtual reality environments (which also create the illusion of the missing limb, only stronger) are effective in treating phantom limb syndrome .

But this is only the tip of the iceberg when it comes to the bizarre neurological phenomena that Ramachandran investigates. Richard Dawkins dubbed him “the Marco Polo of neuroscience,” and he has lived up to this title, covering everything from neglect of the left visual field to the delusion that one is God. A personal favourite is something called the Capgras’ delusion.

The Capgras’ delusion occurs after a certain type of brain damage where the fusiform gyrus (an area linked to face recognition) is disconnected from the amygdala (which is involved in gauging the emotional significance of stimuli). When a patient with this type of brain damage sees family members and friends, they are utterly convinced that someone is playing a trick on them and that all of these people are impostors, made to look identical to family members or friends (or even family pets).

Why? Ramachandran hypothesized that the unconscious emotional reaction (measured by galvanic skin response) that normally occurs when we encounter a familiar face is absent in these patients. This means that the patient has the same type of emotional reaction upon seeing his own mother as he does a complete stranger. The woman looks exactly like his mother, yet the patient feels like she’s a stranger. In order to make sense of this contradiction, the assumption is made that she must be an impostor. Of course, most of this goes on subconsciously; all the patient is aware of is that there is some joker trying to impersonate his mother.

As Ramachandran points out, it is interesting to think about what this means for rationality. If I had Capgras’ delusion, I would believe a woman who looks and acts exactly like my mother is an impostor just because the emotional processing is missing! Why wouldn’t rational processes take over enough to convince me that it is her? After all, she is sitting in her favourite chair, wearing that same torn housecoat and cackling at Nancy Grace as usual. Is an emotional reaction really that important for me to know it’s her? Oddly, it seems it is.

Besides his work on phantom limbs and the Capgras delusion, Ramachandran has also contributed to our understanding of synesthesia (or “cross-modal perception,” such as perceiving sounds as being coloured), blindsight (the ability to perform fine motor tasks in those who are effectively blind), neglect (the tendency to “ignore” half of the visual field) and numerous optical illusions. To investigate these neurological deficits he has used papers, crayons, envelopes, telephones and simple drawings.

Ramachandran has made many media appearances, written numerous articles for Scientific American (and other academic journals), is in high demand as a speaker, and has an entire NOVA special devoted to his work. Currently, he is tackling the complicated subject of the nature of human consciousness, which he will probably be able to elucidate using such tools as an elastic band and a paper clip. Perhaps Richard Dawkins should have called him “The MacGyver of Neuroscience.”

The bottom line is that you don’t need a lot of fancy technology to do some really cool science. You just need creativity, a childlike curiosity about the world and some ordinary household duct tape.