Understanding the Brain’s Capacity to Learn and Adapt: Dr. Kandel’s Seminal Discovery Opens a World of Possibilities

Eric R. Kandel, M.D.
Eric R. Kandel, M.D.

From The Quarterly, Winter 2012

Despite the halting progress, so far, in developing drugs to combat memory loss in old age, there is something profoundly uplifting about the great discovery of Dr. Kandel’s career, and it may be a legitimate source of hope for better results in the not-distant future. 

This discovery is beautifully captured in one of Dr. Kandel’s early and thought-shifting papers, notes his friend and Columbia colleague of many years, Dr. Herbert Pardes, President of the Foundation Scientific Council since its inception. “The paper was called ‘Psychotherapy and the Single Synapse’ and it deeply influenced many people, including me,” says Dr. Pardes.

Dr. Kandel explains that he set out to say two things in that paper, which appeared in the New England Journal of Medicine in 1979. “First, I pointed out that it was foolish to think that the psychoanalytic approach to mental illness and the biological approach to understanding the brain are in conflict with one another. They really support each other.

“The other point was that insofar as psychotherapy works in people, it is a learning experience. The patient and doctor work together to allow the patient, in a trusting environment, to relive earlier memories, earlier traumas and to rework them.” It’s a form of learning that involves memory recall and the reworking of memory. This is highly relevant for many psychiatric illnesses, from depression to post-traumatic stress disorder.  

And the optimism? It is inherent, it can be said, in the nature of the biology that makes remembering and learning possible. “I predicted, and scientists have now shown, that when psychotherapy works it’s because it produces anatomical changes, changes in the strength of synaptic connections,” says Dr. Kandel. This is his great discovery —that the tiny gaps across which adjacent nerve cells communicate are plastic; their strength changes in response to experience. When a memory is encoded, the connections at relevant synapses become stronger; when a memory is modified, the connection might become stronger or weaker.  

But the arguably uplifting point is that experience routinely modifies our synapses. It is uplifting because it suggests that any given synaptic configuration is neither “given” nor “fixed as is” for as long as an organism lives. We change, our synapses change, in response to experience. It’s what enables one of Dr. Kandel’s dear friends, the renowned painter Chuck Close, to be one of the foremost portrait artists of our era—this, despite the remarkable fact that Mr. Close is “face-blind”—his brain is configured in such a way that it does not normally process the cues that enable us to recognize individual faces, one of the defining human attributes.  

“Chuck has solved the problem,” Dr. Kandel explains. “He has learned that he doesn’t have difficulty with faces when they’re flat, only when they’re presented to him in three dimensions. So he makes a photograph; he lays it down and draws a grid over it; then he transfers that to canvas, piece by piece. This only begins to suggest that there are many ways around things, as a result of the creativity and plasticity of the brain.”

At the moment, science knows no way in which memory loss—whether Alzheimer’s or non-Alzheimer’s—can be rescued. But in the knowledge that the brain is, in biological terms, a plastic, if stupendously complicated, entity, there is more than mere hope; there is a reason based in science to believe that we can modify biological processes that lead to brain dysfunction. The possibilities for effectively treating, preventing, curing mental illness are not far-fetched illusions—with the work of scientists like Dr. Kandel evolving what we know about the brain and how it works, these goals are within our reach.