Mindfulness Trains Focused Attention

Last week I made an off-hand claim about “the advantages of mindfulness for attention being well documented in high-tier research journals”. This Mindful Monday, let’s have a look at one of those studies in more detail.

In 2007, Amishi Jha and colleagues presented a fascinating study that looked at mindfulness benefits in both novice and experienced meditators. The key insight behind this research was that both meditators and attention researchers talked about attention in similar ways. Meditators first practice concentrative attention, where you try to maintain focus on a single thing (usually, your breath), and later cultivate receptive attention, where you try to maintain an open awareness of your surroundings. Meanwhile, attention researchers suggest differences between top-down attention, which includes “orienting” your attention to one thing and “conflict monitoring” to ignore distractions, and bottom-up attention, which includes “alerting” to something that appears in the environment. If you noticed that concentrative sounds a lot like top-down, and receptive sounds similar to bottom-up, you’re in good company; that’s just what Jha and her colleagues built their study around.

First, let’s consider concentrative/top-down attention. This is the kind of attention that most meditators start with, particularly in Mindfulness Based Stress-Reduction (MBSR): Try to pay attention to nothing but your breath; let any other thoughts arise, and then set them aside, and get back to your breath. Sometimes attention is directed to a body scan, where you attend to each part of your body in turn, and sometimes to your steps in a walking meditation, but always you try to hold one thing in mind to the exclusion of all else. Naturally, Jha et. al. expected that meditation would train how well people could focus on one thing and ignore distractions.

A good first step to testing the benefits of meditation is to compare long-term meditators to similar people who have never meditated; this lets researchers see if there are benefits after months or years of meditating, without actually having to keep track of participants for months or years and hope they’re following your instructions. So Jha et al. compared an unspecified number of people who had been meditating for between 4 months and 30 years (about 5 years on average) to 34 medical or nursing students with zero meditation experience.

As a test of top-down attention, everyone completed a version of the “flanker” task. The instructions in this task seem very simple: There’s an arrow in red, and you have to press a key to show which direction the arrow is pointing in, left or right. The trick is that the arrow isn’t presented by itself. Sometimes it’s surrounding by other arrows all pointing the same direction, and sometimes it’s surrounded by arrows that are all pointing the opposite direction. Most adults are still quite good at the task when the surrounding arrows don’t match the center arrow – but they do slow down. The better your top-down attention (specifically, “conflict monitoring”), the less you’ll slow down; in other words, Jha et al. predicted that meditators would be less distracted by arrows pointing in the wrong direction.

To add another layer to this task, sometimes the arrow would appear on the top of the screen, and sometimes it would appear on the bottom. The researchers would present a little asterisk on the screen before the arrows appeared; sometimes it was in the center, and didn’t tell anyone much beyond “get ready”, and sometimes it was on the top or bottom, letting people know where the arrows were going to appear. That location information can help you direct your attention to the right place and respond faster – if you have good top-down attention. So Jha et al. also predicted that meditators could be helped more by the location information.

As predicted, experienced meditators seemed to have advantages in top-down attention. Everyone was slower to identify an arrow’s direction when is was surrounded by mismatched arrows, but the experienced meditators weren’t quite as slow: They only slowed about 90 milliseconds (that’s .09 seconds), while novices slowed about 110 milliseconds. That difference might not sound like much, but put it in the context of needing to slam on the brakes to avoid a car crash, and every tenth of a second becomes important. It’s also more impressive if you consider that the meditators were quite a bit older than the novices – 35 years on average, compared to only 24 years – and people tend to get slower on this task as they age. The experienced meditators weren’t helped by the location cue any more than the novices, but overall there was decent evidence that meditators had better top-down attention.

Unfortunately, this kind of research doesn’t really prove that meditation improves attention, because Jha and her colleagues couldn’t control or even measure what led the experienced meditators to meditation. It’s possible that they managed to become experienced meditators because they had good attention, could do the focused meditation exercises more easily, and so didn’t give up in frustration. Fortunately, about half of the medical/nursing students who had never meditated before were signed up for an MBSR course of their own: They would take a 3-hour lesson each week for the next 8 weeks, with homework assignments to practice their meditation. Although they chose to be in the group, I can say from experience that joining an MBSR course has more to do with beliefs about what might help reduce stress (or a certain amount of desperation) than how good one’s attention is.

At the start of those 8 weeks, the medical students who were enrolled in MBSR had the same attention skills as the students who didn’t enroll; after those 8 weeks, though, the meditating students had better top-down attention. Oddly, their improvement was the opposite of the experienced meditators’ advantage: They were better at orienting to the location cue and using it to help them solve the flanker task, but they weren’t any better at managing the conflict of the mismatched arrows. Jha et al. think the task just isn’t sensitive enough – and when you consider that the experienced meditators only had a 20 millisecond advantage, you can see how difficult it might be to see an advantage – but it could also be that short-term meditating improves orienting, and only long-term meditating will carry over to conflict management.

There was one odd thing about Jha’s study, though: They included a group of experienced meditators with those medical students who weren’t in the MBSR course. So the students in MBSR did better than students not in it, but also better than a group of young experienced meditators who had just finished an intense month-long meditation retreat. Even though Jha and her colleagues say that the retreatant meditators would be practicing a different style of meditation (that “open awareness” mentioned earlier), it’s really bad form to have combined such different groups of people together to compare to the MBSR students. It’s not unlike taking a bunch of students who have just finished a summer chess camp, and comparing them to one group of people, some of whom don’t know the rules of chess and some of whom are grandmasters. It means those findings have to be taken with a grain of salt, and I personally had to remind myself that there are other studies that also show attention improvements with meditation, although with slightly different tasks.

Why did Jha’s study get published if there’s such a hiccup in the comparison they made? It goes back to that difference between concentrative and receptive attention. Jha’s study didn’t just show that short-term meditation training helps concentrative attention; it also showed that long-term meditation would start having benefits on receptive attention. But that part of the study will have to wait for another week.

ResearchBlogging.org
Jha, A.P., Krompinger, J., & Baime, M. J. (2007). Mindfulness training modifies subsystems of attention. Cognitive, Affective, & Behavioral Neuroscience, 7, 109-119 DOI: 10.3758/CABN.7.2.109

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