Everyone knows that it is impossible to concentrate with a splitting headache, but now neuroscientists can explain why. Researchers at the University Medical Center Hamburg-Eppendorf in Germany have identified a region of the brain that processes both working memory and pain, and it seems to give preference to painful stimuli. Using functional magnetic resonance imaging, the researchers found that applying pain to volunteers' hands increased activity in brain areas involved in pain processing, while decreasing activity in areas that were working on the assigned visual task.

Ulrike Bingel, who led the study, says the work might have implications for pain management. When doctors decide whether to use strong painkillers such as opiates, they weigh the cognitive side effects of treatment, Bingel says, but they do not always consider that the pain itself can interfere with mental function.