The Dalai Lama helps scientists show the power of the mind to sculpt our gray matter. Although science and religion are often in conflict, the Dalai Lama takes a different approach. Every year or so the head of Tibetan Buddhism invites a group of scientists to his home in Dharamsala, in Northern India, to discuss their work and how Buddhism might contribute to it.
In 2004 the subject was neuroplasticity, the ability of the brain to change its structure and function in response to experience. The following are vignettes adapted from “Train Your Mind, Change Your Brain,” which describes this emerging area of science: The Dalai Lama, who had watched a brain operation during a visit to an American medical school over a decade earlier, asked the surgeons a startling question: Can the mind shape brain matter?
Over the years, he said, neuroscientists had explained to him that mental experiences reflect chemical and electrical changes in the brain. When electrical impulses zip through our visual cortex, for instance, we see; when neurochemicals course through the limbic system we feel.
But something had always bothered him about this explanation, the Dalai Lama said. Could it work the other way around? That is, in addition to the brain giving rise to thoughts and hopes and beliefs and emotions that add up to this thing we call the mind, maybe the mind also acts back on the brain to cause physical changes in the very matter that created it.
If so, then pure thought would change the brain’s activity, its circuits or even its structure. One brain surgeon hardly paused. Physical states give rise to mental states, he asserted; “downward” causation from the mental to the physical is not possible. The Dalai Lama let the matter drop. This wasn’t the first time a man of science had dismissed the possibility that the mind can change the brain.
But “I thought then and still think that there is yet no scientific basis for such a categorical claim,” he later explained. “I am interested in the extent to which the mind itself, and specific subtle thoughts, may have an influence upon the brain.” The Dalai Lama had put his finger on an emerging revolution in brain research. In the last decade of the 20th century, neuroscientists overthrew the dogma that the adult brain can’t change.
To the contrary, its structure and activity can morph in response to experience, an ability called neuroplasticity. The discovery has led to promising new treatments for children with dyslexia and for stroke patients, among others. But the brain changes that were discovered in the first rounds of the neuroplasticity revolution reflected input from the outside world.
For instance, certain synthesized speech can alter the auditory cortex of dyslexic kids in a way that lets their brains hear previously garbled syllables; intensely practiced movements can alter the motor cortex of stroke patients and allow them to move once paralyzed arms or legs.
The kind of change the Dalai Lama asked about was different. It would come from inside. Something as intangible and insubstantial as a thought would rewire the brain. To the mandarins of neuroscience, the very idea seemed as likely as the wings of a butterfly leaving a dent on an armoured tank.
Neuroscientist Helen Mayberg had not endeared herself to the pharmaceutical industry by discovering, in 2002, that inert pills — placebos — work the same way on the brains of depressed people as antidepressants do. Activity in the frontal cortex, the seat of higher thought, increased; activity in limbic regions, which specialize in emotions, fell.
She figured that cognitive-behavioural therapy, in which patients learn to think about their thoughts differently, would act by the same mechanism. At the University of Toronto, Dr. Mayberg, Zindel Segal and their colleagues first used brain imaging to measure activity in the brains of depressed adults. Some of these volunteers then received paroxetine (the generic name of the antidepressant Paxil), while others underwent 15 to 20 sessions of cognitive-behavior therapy, learning not to catastrophize.
That is, they were taught to break their habit of interpreting every little setback as a calamity, as when they conclude from a lousy date that no one will ever love them.