What a brush with death taught David Eagleman about the mysteries of time and the brain
Eagleman’s program was a theoretical as well as a technical feat: it showed that brain cells can exchange information not just through neurotransmitters but through the ebb and flow of calcium atoms. He went on to earn a postdoc at the prestigious Salk Institute, near San Diego. Once there, though, he fell under the spell of Francis Crick, a biologist interested in more than clever simulations. Crick was eighty-three when Eagleman met him, in 1999. He had won the Nobel Prize with James Watson almost forty years earlier, for deciphering the structure of DNA, but his research had taken a hard left turn since then, from genetics to the study of consciousness. “We’d have these seminars and he’d sit there and his head would nod, and I’d think, Oh, poor guy, the tolls of senescence,” Eagleman recalls. “Then he’d get this smile on his face and raise his hand-and just disembowel the speaker. I’d never seen anything like that.”
For decades, brain researchers had taken their lead from behaviorists like B. F. Skinner. They treated their subject as a machine like any other, with inputs, outputs, and a shadowy mechanism in between. But Crick and a handful of other researchers believed that it was time to pry open Skinner’s black box-to at least begin to identify the mechanics of individual awareness. “When I started out, you basically weren’t allowed to talk about it,” Eagleman says. “Why does it feel like something to be alive? Why, when you put together millions of parts, does something suddenly have a sense of itself? All of this went out the window after B. F. Skinner. And it took a guy with Crick’s gravitas to come in and say, ‘You know what? This is a scientific problem-the most exciting of our time.’ ” Crick called it the scientific search for the soul.
“Living in the past may seem like a disadvantage, but it’s a cost that the brain is willing to pay,” Eagleman said. “It’s trying to put together the best possible story about what’s going on in the world, and that takes time.” Touch is the slowest of the senses, since the signal has to travel up the spinal cord from as far away as the big toe. That could mean that the over-all delay is a function of body size: elephants may live a little farther in the past than hummingbirds, with humans somewhere in between. The smaller you are, the more you live in the moment. (Eagleman suspects that the speed of an animal’s mating call-from the piping of a chickadee to the plainchant of a humpback-is a proxy for its sense of time.) “I once mentioned this in an NPR interview and I got flooded by e-mails from short people,” Eagleman said. “They were so pleased. For about a day, I was the hero of the short people.”
This is a rich, long neuroscience article woven with an engaging narrative on a scientific process, or maybe better said, an exploration. It’s so well done, that I feel no single excerpt can do it justice. Highly recommended.
Tip my hat with thanks to Purplegem