How the Brain Learns from Mistakes


by Kayt Sukel

October 16, 2012

Imagine renting a car in the United Kingdom. Though you may be an experienced driver on American soil, making the switch to the “wrong” side of the road can be a bit of a challenge. You have to remain vigilant and pay close attention to the new rules, as well as inhibit your automatic tendency to want to drive on the right. Chances are, you will also make a few mistakes at first or as you grow tired.

Common wisdom holds that we learn best from our mistakes. But researchers at Michigan State University have published a new study that suggests something more is needed: We must be conscious of our mistakes to reap the benefits of improved performance.

Learning from our errors

Change happens every day. Your web-based email account may update itself and move important settings to new locations. Your child’s school will enforce a new drop-off/pick-up policy. Your work’s accounting department may start using new timecard software. Or, you may find yourself behind the wheel of a rental car in Cardiff, Wales. When rules change, especially in a task that you are very familiar with, they can be difficult to assimilate.

“These rule changes can be really simple things. But they are things that can lead to more effort, more mistakes and, eventually, a lot of frustration,” says Jason Moser, director of Michigan State University’s clinical psychophysiology lab. “You have to keep in mind the new way of doing things while suppressing the old way. It’s a lot of work and is hard to overcome at first.”

Since the days of B.F. Skinner’s iconic behaviorism experiments, cognitive psychologists have known that initial learning is very powerful—and difficult to undo. Work from Redmond O’Connell at Trinity College Dublin also suggests that we need to be aware of our errors in order to learn any new approach.

“We know that we all make mistakes that we simply aren’t conscious of. But it would seem that awareness of an error plays an important role in being able to correct your behavior in the real world,” says O’Connell. “That has been harder to demonstrate in the lab, but there is now some data that suggests that being aware of your errors leads to improvement in performance later on.”

Response-switching and the brain

While neuroscientists and cognitive psychologists across the globe have focused on different aspects of task-switching over the years, to date, they have not looked at how switching tasks and monitoring errors intersect. Moser and graduate student Hans Schroder believed that the two are closely connected and ultimately influence task performance. To test the idea, they measured event-related brain potentials (ERPs), or the brain’s electrophysiological response to stimuli, using electrodes placed on the scalp, as study participants looked at strings of M’s and N’s. If the letter M was in the middle of the string, participants were to press a button on the left; if the letter N was in that position, they were to press one on the right. After 50 trials with those rules, the experimenters reversed the rules, asking participants to press the left button when the N was in the middle and the right button for the M. Using ERPs allowed the group to not only look at task performance and response times but also brain activity in regions implicated in action-monitoring and error awareness. The results were published online in Cognitive, Affective & Behavioral Neuroscience on July 15.  

“ERPs give us a precise look at the timing of specific brain operations. We wanted to know what was happening moment to moment in the brain,” says Moser. “Neuroimaging can tell you where things are happening in the brain but not necessarily when in time those things are happening. ERPs allow us to look at how the brain is processing things from A to Z and connect the dots in between.”

The group found activity in the anterior cingulate cortex, which is believed to signal when conflicts between old and new rule sets occur.

“What we saw is activity suggesting that people were successfully suppressing the old response when they were successful in a trial,” says Moser. “But when they made a mistake, they weren’t suppressing the old rule.” 

They also found activity in the centro-pariental region of the brain after errors were made, suggesting that participants were so overwhelmed by the conflict that they weren’t always aware of their errors—and, as such, were not actually learning from their mistakes or improving their overall performance after the task rules changed.

“When participants made a mistake, they became really focused on correcting that response—almost to the point that they lost sight of the fact that they were supposed to keep moving on to the next trial,” he says. “But if they did not recognize their response as wrong beyond a really initial, subconscious level [as determined by that centro-parietal activation], they weren’t able to process that mistake enough to rebound from it.” 

Moving Forward

Moser says they were surprised that the results told such a coherent story about what happens in the brain when it encounters a conflict.

“We expected this increased error-related negativity—this idea that once you have to think about more than one thing and decide between two options that it would be more work for the brain,” he says. But they were surprised to see this further loss of attention to mistakes, and ultimately task performance, when the brain could not overcome the conflict.

O’Connell maintains that there is still some debate about whether you have to be conscious of your errors in order to benefit from them, yet this finding fits in well with the data from patients with deficits in awareness. “Those with traumatic brain injury or other brain injuries that result in impairments in self-awareness suggest that your level of awareness of your own symptoms, for example, actually correlates with the probability that you’ll recover from them,” he says. “But there is still quite a bit we need to learn about conscious awareness and the role it plays in performance and judgment before we can say for certain.”