Forty-eight undergraduates were randomly assigned to either a mindfulness class or a nutrition class. Both classes met for 45 minutes, four times a week, for two weeks. During the mindfulness class, participants sat on cushions in a circle; they were asked to pay focused attention to some aspect of sensory experience, like the sounds of their own breathing. They practiced distinguishing between the simple thoughts that naturally arise in our minds (I have a test tomorrow) and the thoughts that become “elaborated” with emotion (I’m really worried that I won’t do well, and if I fail it, I’ll have to take the class over, and then I won’t graduate on time). The undergrads enrolled in the mindfulness class were taught how to reframe these more emotional concerns as mere “mental projections,” and how to allow their minds to rest naturally, rather than trying to suppress or get rid of their thoughts.
The results were clear: Participants who received mindfulness training showed improved accuracy on the GRE and higher working memory capacity, compared to those who received instruction in nutrition. Analyses indicated that the improvement could be explained, at least in part, by reduced mind wandering during the task.
The researchers estimated that mindfulness training resulted in the equivalent of a 16 percentile-point boost on the GRE, on average.