DHARAMSALA, INDIA, November 5, 2004: Although the Buddhists and scientists who met for five days last month in the Dalai Lama’s home in Dharamsala, India, had different views on the matters of reincarnation and the relationship of mind to brain, they set them aside in the interest of a shared goal. They had come together to discuss one of the hottest topics in brain science: neuroplasticity. The term refers to the brain’s recently discovered ability to change its structure and function, in particular by expanding or strengthening circuits that are used and by shrinking or weakening those that are rarely engaged. In its short history, the science of neuroplasticity has mostly documented brain changes that reflect physical experience and input from the outside world. Lately scientists have begun to wonder whether the brain can change in response to purely internal, mental signals. That’s where the Buddhists come in. Their centuries-old tradition of meditation offers a real-life experiment in the power of thoughts to alter the physical matter of the brain.
In Dharamsala, the resulting brain scans compared brain activity in volunteers who were novice meditators to that of Buddhist monks who had spent more than 10,000 hours in meditation. The task was to practice “compassion” meditation, generating a feeling of loving kindness towards all beings. In a striking difference between novices and monks, the latter showed a dramatic increase in high-frequency brain activity called gamma waves during compassion meditation. Thought to be the signature of neuronal activity that knits together far-flung brain circuits, gamma waves underlie higher mental activity such as consciousness. The novice meditators “showed a slight increase in gamma activity, but most monks showed extremely large increases of a sort that has never been reported before in the neuroscience literature,” says neuroscientist Richard Davidson of the University of Wisconsin, suggesting that mental training can bring the brain to a greater level of consciousness.
Using the brain scan called functional magnetic resonance imaging, the scientists pinpointed regions that were active during compassion meditation. In almost every case, the enhanced activity was greater in the monks’ brains than the novices’. Activity in the left prefrontal cortex (the seat of positive emotions such as happiness) swamped activity in the right prefrontal (site of negative emotions and anxiety), something never before seen from purely mental activity. A sprawling circuit that switches on at the sight of suffering also showed greater activity in the monks. So did regions responsible for planned movement, as if the monks’ brains were itching to go to the aid of those in distress, says this article. The study will be published next week in Proceedings of the National Academy of Sciences.
Courtesy of http://www.HinduismToday.com/ and Jaya Tirtha Caran: http://www.hknet.org.nz/