Meditation does more than simply increase feelings of calmness and a sense of well-being—it changes the structure of the brain and increases its effectiveness, confirm researchers.
The practice of meditation increases the brain's energy, and certain meditators state they need less sleep. Many studies have shown that the brain functions differently during meditation—there is a change in the brain waves and synchronization of neuronal activity, for example—but the concept that it can offer some of the restorative aspects of sleep had not yet been explored.
According to an article in New Scientist , Nov. 15, 2005, a group of researchers from the University of Kentucky studied the subject. They used a test known as "psychomotor vigilance task," which measures the reaction time to external stimuli, and makes it possible to quantify the effects of sleep on mental alertness. In this test a subject stares at a television screen and presses a button as soon as an image appears.
Typically, people need 200 to 300 milliseconds to respond, except for those sleep-deprived people who are much slower, sometimes missing the image completely. In this experiment the Kentucky researchers tested ten volunteers before and 40 minutes after sleep, meditation, reading or conversation. Each subject was tested in each state.
The positive effect of a small nap was already known, and thus only confirmed. The researchers on the other hand were surprised to discover that meditation led immediately to an improvement in performance. However, none of the volunteers had practiced meditation before.
"Each person tested showed psychomotor improvement," said Dr. Bruce O'Hara, one of the researchers, while acknowledging not having any explanation for the phenomenon. The improvement was even more apparent after a night without sleep.
The effect, real or imagined, that meditation has on the brain has been the subject of intense debate. Dr. Sara Lazar, from Massachusetts General Hospital in Boston, used MRI (Magnetic Resonance Imaging) to compare the brain structure of 15 meditators having 1 to 30 years' meditation experience, with that of 15 people who had never meditated.
They observed that the cerebral cortex was thicker for the meditators. That was particularly true of the areas of the brain related to attention and sensory processing, namely the prefrontal cortex and the right anterior insula. "You are exercising it while you meditate, and it gets bigger," comments Lazar. Studies have already shown that accomplished musicians, athletes and linguists also have thickening in specific areas of the cerebral cortex.
Dr. O'Hara's team is now studying experienced meditators.