At the Society for Neuroscience meeting, several researchers are to present new findings on the meditating brain. In one study, Sara Lazar of Massachusetts General Hospital in Boston put meditators and non-meditators into an MRI brain scan to study the structure (and ultimately the function) of their brains. "People who meditate always talk about lasting effects that go beyond the meditation session," Lazar said in a telephone interview last week. "If so, the implication is that different brain wiring supports this change."

According to Lazar's study, which appears tomorrow in NeuroReport, 30 volunteers who had practiced meditation anywhere from one year to three decades had thicker brain tissue in two regions - the insula and the prefrontal cortex - than 20 non-meditators in the study. The insula is involved in pain perception, hunger, the perception of heart rate and breathing, and the integration of emotion and thought. The prefrontal cortex mediates attention, memory and decision-making.

Tissue loss slows

This thickening, Lazar said, "gives credibility to the claims of meditators. It is not just sitting there quietly, but meditating, that is having a profound effect on key brain structures." Normally, the prefrontal cortex thins with age, but meditating seems to slow this tissue loss, she said.

The next studies under way in her lab are designed to test whether meditators have better working memory and attention. She wants to test whether meditators have better control over their daily planning and decisions. The National Institutes of Health and the Centers for Disease Control and Prevention have funded her research.

For more information on neuroscience and meditation: www .investigatingthemind.org. The Society for Neuroscience Web site is www.sfn.org.