Before smirking the next time you see someone put the milk in the pantry and the cereal in the fridge, you should know that your brain may be rehearsing the same mistake. A new study finds that a brain region thought to be important for detecting our own mistakes also picks up on those of others. The finding may provide insight into how we learn from watching people around us and into cooperative behaviors.
The anterior cingulate cortex acts like the brain's watchdog: It monitors our behavior and goes off if the outcome of an action isn't what was anticipated. Some neuroscientists, therefore, believe the region is important for detecting and correcting errors.
Previous work hinted that the anterior cingulate also fires up, although a bit belatedly, when people see someone else make a mistake. To investigate further, cognitive neuroscientist Michael Coles at the Danders Centre for Cognitive Neuroimaging in the Netherlands and colleagues invented a task in which one volunteer sat at a computer screen and punched a button for "left" or "right" depending on which direction the middle arrow in a row of arrows pointed. Meanwhile, another volunteer looked on. The observer, however, could only see the all-important middle arrow, making it easy to tell when the first volunteer made a mistake. When that happened, EEG recordings revealed that the button pusher's anterior cingulate revved up, as expected. And a couple hundred milliseconds later, the observer's anterior cingulate fired up too, suggesting it had noticed the mistake.
The researchers then looked at a particular pattern of activity, called the LRP, in the motor cortex that signals an impending movement such as pressing a button. Just before zapping the wrong button, however, the button pusher's LFP was diminished, suggesting that the motor cortex "knew" it was about to make a mistake, even if it was too late to change course. The observer's LRP also showed a dip, after a short delay, suggesting that the observer's motor system also caught the error, the scientists report 25 April in Nature Neuroscience.
"The paper shows that when monitoring someone else's behavior, you are doing what they do in your brain," says cognitive neuroscientist William Gehring of the University of Michigan, Ann Arbor. And it could be that the anterior cingulate pays attention in social situations, he speculates, such as cooperative tasks that rely on predicting the behavior of other people.