We’ve all experienced the fading of our ability to concentrate when we’ve been focused on a task for too long. The dominant theory of why this should be so has been around for half a century, and describes attention as a limited resource that gets ‘used up’. Well, attention is assuredly a limited resource in the sense that you only have so much of it to apply. But is it limited in the sense of being used up and needing to refresh? A new study indicates that it isn’t.

The researchers make what strikes me as a cogent argument: attention is an endless resource; we are always paying attention to something. The problem is our ability to maintain attention on a single task without respite. Articulated like this, we are immediately struck by the parallel with perception. Any smell, touch, sight, sound, that remains constant eventually stops registering with us. We become habituated to it. Is that what’s happening with attention? Is it a form of habituation?

In an experimental study, 84 volunteers were tested on their ability to focus on a repetitive computerized task for 50 minutes under various conditions: one group had no breaks or distractions; two groups memorized four digits beforehand and were told to respond if they saw them on the screen during the task (but only one group were shown them during the task); one group were shown the digits but told to ignore them if they saw them.

As expected, performance declined significantly over the course of the task for most participants — with the exception of those who were twice shown the memorized digits and had to respond to them. That was all it took, a very brief break in the task, and their focus was maintained.

The finding suggests that prolonged attention to a single task actually hinders performance, but briefly deactivating and reactivating your goals is all you need to stay focused.

I’ve talked about the importance of retrieval practice at length, so I’m pleased to report on the latest study to confirm its value. Indeed, this study demonstrates that practicing retrieval is a more effective strategy than elaborative studying.

In two studies, a total of 200 students studied texts on topics from different science disciplines. One group engaged in elaborative studying by creating concept maps. The second group read the texts, then put the material away and practiced recalling the concepts from the text. Both groups performed at about the same level on a test at the end of the study period. However, when the students were tested again a week later, the group that studied by practicing retrieval performed 50% better than the group that studied by creating concept maps.

The test involved understanding as well as memory, with some of the questions asking them to draw connections between things that weren't explicitly stated in the material.

The study also confirms that most students are poor at judging the success of their study habits. Asked to predict which technique would produce better results, most thought that concept mapping would be superior.

The findings should certainly not be taken as a slur on concept mapping, which is a study strategy of proven effectiveness. Moreover, while concept mapping can be used solely as an elaborative study method (as it was in these experiments), it can also be used as a retrieval practice technique.

In a recent study, volunteers were asked to solve a problem known as the Tower of Hanoi, a game in which you have to move stacked disks from one peg to another. Later, they were asked to explain how they did it (very difficult to do without using your hands.) The volunteers then played the game again. But for some of them, the weight of the disks had secretly reversed, so that the smallest disk was now the heaviest and needed two hands.

People who had used one hand in their gestures when talking about moving the small disk were in trouble when that disk got heavier. They took longer to complete the task than did people who used two hands in their gestures—and the more one-handed gestures they used, the longer they took.

For those who had not been asked to explain their solution (and replayed the game in the interval) were unaffected by the disk weights changing. So even though they had repeated the action with the original weights, they weren’t thrown by the unexpected changes in weights, as those who gestured with one hand were.

The findings add to the evidence that gestures make thought concrete. Related research has indicated that children can come to understand abstract concepts in mathematics and science more readily if they gesture (and perhaps if their teachers gesture).

A working memory training program developed to help children with ADHD has been tested by 52 students, aged 7 to 17. Between a quarter and a third of the children showed significant improvement in inattention, overall number of ADHD symptoms, initiation, planning/organization, and working memory, according to parental ratings. While teacher ratings were positive, they did not quite reach significance. It is worth noting that this improvement was maintained at the four-month follow-up.

The children used the software in their homes, under the supervision of their parents and the researchers. The program includes a set of 25 exercises in a computer-game format that students had to complete within 5 to 6 weeks. For example, in one exercise a robot will speak numbers in a certain order, and the student has to click on the numbers the robot spoke, on the computer screen, in the opposite order. Each session is 30 to 40 minutes long, and the exercises become progressively harder as the students improve.

The software was developed by a Swedish company called Cogmed in conjunction with the Karolinska Institute. Earlier studies in Sweden have been promising, but this is the first study in the United States, and the first to include children on medication (60% of the participants).

It’s well known that being too anxious about an exam can make you perform worse, and studies indicate that part of the reason for this is that your limited working memory is being clogged up with thoughts related to this anxiety. However for those who suffer from test anxiety, it’s not so easy to simply ‘relax’ and clear their heads. But now a new study has found that simply spending 10 minutes before the exam writing about your thoughts and feelings can free up brainpower previously occupied by testing worries.

In the first laboratory experiments, 20 college students were given two math tests. After the first test, the students were told that there would be a monetary reward for high marks — from both them and the student they had been paired with. They were then told that the other student had already sat the second test and improved their score, increasing the pressure. They were also they’d be videotaped, and their performance analyzed by teachers and students. Having thus upped the stakes considerably, half the students were given 10 minutes to write down any concerns they had about the test, while the other half were just given 10 minutes to sit quietly.

Under this pressure, the students who sat quietly did 12% worse on the second test. However those who wrote about their fears improved by 5%. In a subsequent experiment, those who wrote about an unrelated unemotional event did as badly as the control students (a drop of 7% this time, vs a 4% gain for the expressive writing group). In other words, it’s not enough to simply write, you need to be expressing your worries.

Moving out of the laboratory, the researchers then replayed their experiment in a 9th-grade classroom, in two studies involving 51 and 55 students sitting a biology exam. The students were scored for test anxiety six weeks before the exam. The control students were told to write about a topic that wouldn’t be covered in the exam (this being a common topic in one’s thoughts prior to an exam). It was found that those who scored high in test anxiety performed poorly in the control condition, but at the level of those low in test anxiety when in the expressive writing condition (improving their own performance by nearly a grade point). Those who were low in test anxiety performed at the same level regardless of what they wrote about prior to the exam.

One of the researchers, Sian Beilock, recently published a book on these matters: Choke: What the Secrets of the Brain Reveal About Getting It Right When You Have To