We learn more from our mistakes than from our successes, the old cliché says—and now scientists know why. Researchers at the University of Exeter in England discovered a brain mechanism that alerts us to situations in which we previously went wrong.
In the study, students playing physicians had to diagnose a fictitious disease based on images from equally fictitious blood samples. When participants saw images that had previously led them to an erroneous diagnosis, warning signals in the brain appeared only a tenth of a second later—much more quickly than did signals triggered by images that had resulted in a correct diagnosis. Earlier studies had confirmed that slipups do indeed result in better learning, but this one is the first to show the brain's specific reaction to a prior blunder.