Meditation Apparently Activates Positive Areas Within the Brain
Meditation is often promoted as a tool for alleviating stress and anxiety, but exactly why it calms the nerves has long mystified scientists. A study published in February offers a few clues. For the first time ever, a team of medical researchers led by Richard Davidson, director of the Laboratory for Affective Neuroscience at the University of Wisconsin at Madison, showed that meditation activates an area of the brain associated with positive emotions. A randomly selected group of middle-class volunteers with stressful jobs took an eight-week course in Mindfulness Meditation given by author Jon Kabat-Zinn, a professor at the University of Massachusetts Medical School. A control group from the same pool of volunteers did not receive any meditation training. To establish a baseline, everyone was given electroencephalograms.
After the course, both groups were asked to pick two intense emotional experiences they’d had—one good, one bad—and write about them while their brains’ electrical activity was monitored. Whether they summoned a happy or an unhappy memory, the meditation group showed markedly more electrical activity in their left prefrontal cortex—the locus of positive, optimistic emotions—than they had in their baseline test or than the control group had in either reading. “This shows that these changes are not just ‘in your head,’ so to speak,” says Davidson. “The meditation produced real changes in the brain.”
—Michael W. Robbins
Chronic Stress Triggers Overeating
Ever wonder why you find yourself raiding the icebox or tearing through a bag of potato chips when you feel completely frazzled? In September a team led by physiologist Mary Dallman of the University of California at San Francisco subjected lab rats to a series of stress tests and learned how comfort food manages to comfort. During times of chronic stress, foods laden with sugar and calories act as a brake on the body’s overworked emergency response system.
Say your dander is up because your boss just threatened to fire you. Acute stress, says psychologist Norman Pecoraro, provokes a flurry of brain signals to the adrenal glands, which in turn release a flood of cortisol and other hormones. This release is self-limiting; the cortisol itself eventually triggers a shut-off mechanism. When the immediate crisis passes, the cortisol level abruptly decreases. But when you encounter threatening situations for days or weeks on end, the brain reacts differently. Instead of shutting off the cortisol, it tells the adrenal glands to make even more. High-energy foods help restore hormonal calm.
Unfortunately, such stress-induced overeating has unsightly—and unhealthy—side effects. Test rats that ingested large amounts of sucrose and lard to combat stress developed potbellies within four days.
—Annette Foglino
