101 Theory Drive

101 Theory Drive



The Talking Cure

THE ENGRAM

Save for Lynch, Lynch Lab was empty the day I arrived, a clear blue winter morning in the last week of December 2004. Outside, the parking lot contained nothing but clean black asphalt and bright white lines. Inside, the double ranks of stainless-steel lab benches were bare and quiet. Much to Gary Lynch’s chagrin, every single one of the dozen or so scientists, students, and technicians who worked in the lab had gone on holiday. Lynch’s attitude toward other people’s vacations could most charitably be described as dim. He worked 365 days a year. Why couldn’t they? Especially now.

Scientists in Lynch’s lab at the University of California, Irvine, had recently developed a technique that Lynch, a neuroscientist who had been investigating the biochemistry of memory for more than thirty years, thought would allow researchers for the first time to visualize a trace of memory; that is, to see a map of the physical changes in the brain that occur when a memory is made. This was not an insignificant undertaking. For at least a century, scientists had been trying - and failing - to do exactly what Lynch thought his lab was on the verge of accomplishing: to teach an animal a new skill or experience; to, in other words, expose that animal’s brain to something in the exterior world, then look deeply enough into the close, dark, complicated space that is the mammalian brain and say, with certainty, “There! Right there! That’s it.” “The thing itself,” Lynch sometimes called it, making it sound like a rumored but never- quite-glimpsed spirit in the night.

Such a physical trace of memory is commonly called an engram. Karl Lashley, a famed American psychologist, had popularized the term in the mid-twentieth century and had devoted a significant portion of his career to pursuing it. His search had been exhaustive and, in the end, fruitless.

“This series of experiments has yielded a good bit of information about what and where the memory trace is not,” Lashley wrote. “It has discovered nothing directly of the real nature of the engram. I sometimes feel, in reviewing the evidence on the localization of the memory trace, that the necessary conclusion is that learning just is not possible. It is difficult to conceive of a mechanism that can satisfy the conditions set for it. Nevertheless, in spite of such evidence against it, learning sometimes does occur.”

The history of memory research since Lashley had been rife with heated disagreements about whether such a thing as an engram actually existed, about whether such a thing could actually be seen, about what such a thing would look like if it did exist and could be seen, about where it would be, and, especially, about what did or did not occur inside the brain cells, called neurons, that would cause such a thing to exist. If, that is, it did.

Excerpted from 101 Theory Drive by Terry McDermott Copyright © 2010 by Terry McDermott. Excerpted by permission of Pantheon, a division of Random House, Inc. All rights reserved. No part of this excerpt may be reproduced or reprinted without permission in writing from the publisher.