June 29 (HealthDay News) -- Anxious people have more difficulty tuning out distractions and require more time to shift their attention from one task to another, a new study from British researchers has found.

The study included volunteers who took part in several experiments designed to assess the effects of anxiety on their ability to perform such tasks as avoiding distractions when reading a story or solving a series of simple math problems.

In one test, participants were told to read a story on a computer screen, and their eye movements were recorded as they read. The story included a few unrelated "distracter" words, and the researchers found that anxious people took longer to read the story because they tended to dwell on the irrelevant words, especially when they believed they would be evaluated on their reading comprehension.

In a different experiment, volunteers alternated between multiplication and division problems. Anxious participants took longer to complete the task, the study found.

"A lot of the negative effects of anxiety appear to be caused by difficulties with controlling attention," study co-author Michael Eysenck of Royal Holloway, University of London, said in a news release from the Economic & Social Research Council, which funded the study. "This suggests that training techniques designed to enhance attentional control -- the ability to ignore distractions and to switch attention from one task to another -- could help anxious students to achieve their academic potential."

Eysenck and colleague Nazanin Derakshan also found that anxious people often perform at a level comparable to those who aren't anxious, but at a greater cost in terms of effort and perhaps long-term stress.

"This shows that it is important that teachers focus not only on whether a student's academic performance seems to be OK but also on how much effort the student had to put in to achieve that level," Eysenck said. "Anxious students may be trying desperately hard just to keep up, and this could be at great psychological cost."

The study appears in a recent issue of the council's publication, Society Today.

SOURCE: Economic & Social Research Council, news release, June 2009