Tag Archives: radiolab

The Voices In Your Head

First, some background. Synesthesia is a surprisingly common condition that causes two different sensory pathways to interact in unusual ways. Synesthetes may perceive letters as having dedicated colors, or numbers as having personalities. Read more here. Vilayanur S. Ramachandran is a neurologist: a doctor, a researcher, and an occasional Radiolab guest. Listen to him explain how he performed the first ever phantom-limb “amputation” here.

John Colapinto, in New Yorker profile of Ramachandran last May, found him speculating about the nature of creativity:

The most common synesthesia is number-color. Ramachandran believed it was not coincidental that the fusiform gyrus, where number shapes are processed in the brain, lies next to the area where colors are processed. He suspected that a cross-wiring in the brain, similar to that in phantom-limb patients, was responsible. Brain scans confirmed his hunch: in synesthetes, there are excess neural connections between the two brain centers. This suggested to Ramachandran that the syndrome arises from a defect in the gene responsible for pruning away the neural fibres that connect the various centers of the brain as it develops early in life. “What do artists, poets, and novelists have in common?” Ramachandran asked me. “The propensity to link seemingly unrelated things. It’s called metaphor. So what I’m arguing is, if the same gene, instead of being expressed only in the fusiform gyrus, is expressed diffusely throughout the brain, you’ve got a greater propensity to link seemingly unrelated brain areas in concepts and ideas. So it’s a very phrenological view of creativity.”

It can feel uncomfortable to examine the biology behind creative talent, which we’ve always treated as kind of magical, or divine. But science addressing questions that philosophers and priests once had a monopoly on is a wonderful thing. Nothing is more fascinating or important to us than our own nature, and beginning to build real, concrete knowledge about it is an enormous blessing. Reading about neurology leaves me awed, excited, and impatient. The brain is so marvellously complicated, as are the questions we ask, that our best efforts fall far short of sating our curiosity.

One of the most magnificent puzzles is consciousness itself: why we’re aware of our own thinking, and how we came to be this way. It’s a favorite subject for people who believe that some mental phenomena exist outside physical, testable reality, those who jeer at evidence-based approaches to these unknowns. But Ramachandran is willing to speculate on consciousness, too. Like his hypothesis about metaphors, these ideas are likely wrong, one of the many errors that “trial and error” requires. Still, it’s provocative stuff:

Mirror neurons play a role, he thinks. “One of the theories we put forward,” he said, as he packed up his bag, “is that the mirror-neuron system is used for modelling someone else’s behavior, putting yourself in another person’s shoes, looking at the world from another person’s point of view. This is called an allocentric view of the world, as opposed to the egocentric view. So I made the suggestion that at some point in evolution this system turned back and allowed you to create an allocentric view of yourself. This, I claim, is the dawn of self-awareness.”

I confess I find this possibility absolutely thrilling, especially compared to vague, untestable stories about “supernatural” mechanisms. But of course it doesn’t matter that it’s an appealing story; we have to figure out ways to challenge it, test it, until we know whether it’s true or false. “What we’re hoping,” Ramachandran says, “is that we can grope our way toward the answer, finding little bits and pieces, little clues, toward understanding what conciousness is. We’ve just scratched the surface of the problem.”

Amid insights on vision, autism, and the brain’s body-image map, one last passage caught my eye. “You know that when people think to themselves you get unconscious movement of the vocal chords?” Ramachandran asks. (It’s fun to try to notice this.) Well.

In the case of schizophrenia, whose sufferers often complain of “hearing voices,” Ramachandran suspected damage of deficit in a sensory mechanism in the vocal chords which, when normal people think, sends a signal to the brain indicating “This is simply a thought; no one is actually saying this.” If this mechanism was damaged, the subconscious movement of the vocal chords could be interpreted as an outside voice speaking in one’s head.

“By the way,” Ramachandran continued, “I have a theory that if you take people with carcinoma of the larynx, and you remove the vocal chords, and they think to themselves, they may actually start hallucinating. A prediction.”

A prediction. That’s where we start. Isn’t it great to be alive now?

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Filed under biology, science, skepticism, wild speculation

“Moments” by Radiolab

If possible, watch this fullscreen with a minimum of distractions.

There’s very little I can add to that.

I remembered this video writing about “John Smith” by This American Life, which is similar except it lasts an hour and might be even more beautiful.

Radiolab is a an extremely ambitious and innovative radio show on WNYC, always worth listening to. Check out their podcast and blog.

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Filed under beauty, memory, radio