Meditation: The key to improved attention?

"...a new study from the University of Wisconsin-Madison suggests that attention does not have a fixed capacity - and that it can be improved by directed mental training, such as meditation. "

In this study, subjects received 3 months of intensive training in Vipassana meditation. They then gave them the following test, with promising results.

"Volunteers were asked to look for target numbers that were mixed into a series of distracting letters and quickly flashed on a screen. As subjects performed the task, their brain activity was recorded with electrodes placed on the scalp. In some cases, two target numbers appeared in the series less than one-half second apart - close enough to fall within the typical attentional blink window.

The research group found that three months of rigorous training in Vipassana meditation improved people's ability to detect a second target within the half-second time window. In addition, though the ability to see the first target did not change, the mental training reduced the amount of brain activity associated with seeing the first target. "The decrease [of brain activity associated with the first target] strongly predicted the accuracy of their ability to detect the second target," Davidson says."

I wonder how much of their improvement has to do with practice and learning? The blurb does not mention whether there was a control group of subjects that also took these same tests over the same period of time, but did not get the meditation training.
Either way, this does indicate that attention is something that can be improved, whether it be from meditation, or simply practice of a task.

http://www.sciencedaily.com/releases/2007/05/070507202029.htm