Meditation
Richard Davidson has found that the brains of monks who are the most experienced meditators are different from other brains. They have a much stronger “gamma” wave, a form of electrical activity in the brain that is associated with consciousness and pulling together information and perceptions from different regions of the brain. They also have much greater activity in the left than the right prefrontal cortex (just behind the forehead), a mark of well-being and happiness.
Meditation can change brain circuits linked to attention.
Davidson taught volunteers Vipassana meditation, in which you first focus on an object such as your breath. You then let your focus expand, and let thoughts or perceptions engage your attention, but keep yourself from reacting emotionally or judgmentally.
The volunteers practiced Vipassana meditation for three months, for 10 to 12 hours a day. Another group got only a quickie one-hour course, then practiced Vipassana for 20 minutes a day for a week. Before the training, Davidson tested the volunteers on “attentional blink.” In this glitch, if you pay close attention to one thing it’s hard to notice something that comes hard on its heels, typically within half a second. For instance, Davidson had the volunteers watch a screen where capital letters flashed, one at a time, for one-twentieth of a second. Once or twice in the rapid-fire stream of 15 or so letters, a number snuck in. At the end, the volunteers typed which number or numbers had snuck in.
In general, if a second number creeps in less than half a second after the first, you don’t notice it. The meditators significantly improved their ability to detect the second number amid the barrage of letters, even when it came less than half a second later (the period when paying attention to the first number ordinarily keeps you from noticing the second). In addition, the amount of brain activity associated with seeing the first target fell in the meditators.