The researchers found that by doing this, they could boost participants’ confidence when they were doing a task in a laboratory, regardless of how well they actually performed the task. What’s more, the same technique could be used to decrease confidence, if people were rewarded when their brain activity showed a pattern that was linked to low confidence, according to the researchers.
The finding “adds to the growing body of evidence on how confidence is generated in the brain,” the researchers wrote in the Dec. 15 issue of the journal Nature Communications. [10 Things You Didn’t Know About the Brain]
The same group of researchers recently published a study suggesting that decoded neurofeedback could be used to erase frightening memories.
In the new study, 17 participants had their brains scanned while they performed a perceptual task — they had to determine whether dots on a screen appeared to be moving to the left or right. Then they were asked to rate how confident they were in their choice.
The researchers used their technique to “decode” brain activity patterns, to find patterns linked with the times that participants said that they were very confident in their choice.
The researchers wanted to know, “How is confidence represented in the brain?” study researcher Mitsuo Kawato, director of the Computational Neuroscience Laboratories at ATR, a research institute in Kyoto, Japan, said in a statement. To find out, the researchers looked for specific patterns in the brain “that could reliably tell us when a participant was in a high or low confidence state,” he said.
And then they used this information “to make the occurrence of a confident state more likely to happen in the future,” Kawato said.
To do this, the researchers had participants undergo a “training” session. During the session, the participants lay in a brain scanner while staring at an image of a white disc. They were instructed to “regulate” their brain activity in order to make the disc image grow larger, but they weren’t given any tips for how this might be accomplished. When asked later what they were thinking about in the scanner, participants said things like “I was counting,” “I was focusing on the disc itself,” or “I was thinking about food.”
Unbeknownst to the participants, the disc image grew bigger whenever their brain activity patterns corresponded to those that were observed when they were in their high-confidence states. After the training session, they were given a small, monetary reward that was based on how large they said the disc grew. [Top 10 Mysteries of the Mind]
“By continuously pairing the occurrence of the highly confident state with a reward — a small amount of money — in real time,” we were able to make participants more confident on the perceptual task, said study researcher Aurelio Cortese, also of ATR. The researchers saw these changes in confidence even though participants’ level of accuracy the task didn’t change.
The researchers noted that their study was small, and that they aren’t exactly sure how the technique may be working, on a psychological level, to boost people’s confidence.
But the researchers hope that the technique might one day be used to treat people with certain psychiatric conditions that are associated with changes in confidence. For example, a person’s depression can be made worse if the individual thinks negatively about his or her capacities, the researchers said.
Charan Ranganath, a professor for the Center for Neuroscience at the University of California, Davis, said that the findings were interesting, but they do not necessarily mean that the study participants would experience a confidence boost in other areas of their life.
“There’s a limit to what you can infer from this study,” said Ranganath, who was not involved in the study. “You can train people to be more confident in making left-right decisions, but that doesn’t generalize, necessarily, to any other decision in life,” Ranganath said.
So much more research would be needed to see whether the technique could help people in real-world situations, such as public speaking or social events, Ranganath said.
Ranganath noted that even talk therapy treatments that appear to work in a clinic may not work in the real world, because of the way our brains are wired to learn — that is, we learn things in a way that is specific to a certain situation.
“It’s hard to work against that and get people to learn something that fundamentally generalizes [to other situations], because our brains don’t want to do that,” Ranganath said.
But the study does show that a person’s confidence level is not necessarily related to anything objective.
“It’s kind of another piece of evidence to say, when people are confident, it doesn’t necessarily mean they’re right or wrong,” Ranganath said. “It’s important for people to understand that somebody who’s confidently saying something doesn’t necessarily know more than somebody who’s not confidently saying it.”