Learning to Pay Attention

1188 Our sensory system is constantly bombarded with inputs, but owing to the brain's fi nite processing power, we are forced to pay attention to only a tiny proportion of these inputs at any given time. In a new study, Richard Davidson and colleagues report that intensive training in meditation can alter the way in which the brain allocates attentional resources to important stimuli, allowing people to improve their performance on a demanding visual task. In the " attentional blink " task, volunteers were asked to identify two " target " stimuli—for example, two particular numbers—in a stream of rapidly presented " non-target " stimuli—for example, letters—which are irrelevant to the task. When the fi rst target number appears on the screen, it captures the attention of the subject, and this can prevent the person from spotting the second target if it appears within around half a second of the fi rst (the attentional blink). It is as if the brain is so busy processing the fi rst target that it can't also process the second, and therefore the second target goes unnoticed. However, the attentional blink does not represent a structural processing bottleneck. Most subjects are able to spot the second target on at least a small proportion of trials. Since this task gauges the ability of subjects to allocate cognitive resources effi ciently when multiple stimuli compete for attention, it is perfectly suited for investigations of the effects of mental training on attention. Previous studies had reported that the act of meditation can alter cognitive and perceptual abilities and neural responses. However, Davidson and colleagues wondered whether volunteers who received three months of intensive training in a particular type of meditation, known as Vipassana meditation, would allocate attentional resources more effi ciently and therefore show enhanced performance on the attentional blink task, a task that taps into similar skills used during training without directly involving meditation. Vipassana meditation encourages " non-reactive awareness " —a state of mind in which individuals cultivate awareness of stimuli without judgments or affective responses to those stimuli. Since Vipassana meditation allegedly reduces mental distraction, the authors hypothesized that volunteers (" practitioners ") who attended the intensive training course, which involved 10–12 hours of meditation each day, would be more successful at identifying the second target, because the subjects' attention would be captured less by the fi rst target. Performance on the task before …