SFGate: Brain workout may help anxiety, study suggests

Charles Burress, Chronicle Staff Writer

Wednesday, December 17, 2008

Could Sudoku be a balm for anxious people?

A new study suggests that intellectually demanding challenges like crossword puzzles or chess may be more successful at keeping worry-prone people from worrying than supposedly relaxing pastimes like watching TV or shopping.

Contrary to theories that "as things get harder, anxious people fall apart, this suggests it's the opposite way around," said UC Berkeley psychologist Sonia Bishop, lead researcher on the study published online this week by Nature Neuroscience.

The study showed that anxious people performed just as well as others when facing tasks that demanded concentration, but they took more time than others to complete tasks that were easier, Bishop said.

Their slower response time to challenges not requiring full attention was accompanied by reduced blood flow to the prefrontal cortex, which serves as the brain's CEO in thinking, planning and active memory.

The study indicated that anxious individuals have a weakened ability to block out distractions and that they might benefit from mindfulness training, which often uses meditation and stress-reduction exercises to help increase one's awareness and focus.

"With some very popular therapies like mindfulness training, people aren't sure why they work," Bishop said. "This perhaps gives us a rationale for why they do."

The results also challenge another explanation for why anxious people face day-to-day problems in concentration and work-related cognitive function, Bishop said. It has been argued that the "fight or flight" response center of the brain, the amygdala, overreacts to threat-related stimuli in anxious people, thus playing a central role in undermining concentration. But the new study suggests that attention-focusing ability in such individuals is impaired even when the amygdala is not extra-active, and thus their difficulties with concentration may be determined by a different mechanism, she said.

The study consisted of simple letter-recognition tests given to 17 volunteers, ages 19 to 48, while blood flow to a section in the front of the brain called the dorsolateral prefrontal cortex was measured by magnetic resonance imaging. The volunteers, seven female and 10 male, were from Cambridge, England, where Bishop did research at the University of Cambridge before becoming an assistant professor at Berkeley in July.

The results were scored according to the difficulty of the tests, including the distraction level of extraneous elements, and correlated to the volunteers' degree of anxiety. Surveys indicate that nearly a fifth of U.S. adults suffer from one or more anxiety disorders in a given year, Bishop noted in the study, titled "Trait anxiety and impoverished prefrontal control of attention."