Study Reveals How the Brain Assesses Confidence In Its Decisions

Wellcome Trust researchers have discovered the way a brain evaluates confidence in its decision. They have explained why some people have a better insight into their choices than others.

Decision making is not an inherent trait but it is vital in making life problem-free.

The reason people struggle with the decision making process is because there are so many things to consider. But it is essential to have a strong sense of self-confidence when making a decision.

Specific areas of the brain have been pinpointed by the researchers led by professor Ray Dolan for neuroimaging at UCL. These highlighted areas interact to compute both the value of the choices people have and their confidence in those choices, giving us the ability to know what we want.

With the help of functional magnetic resonance imaging (fMRI) they analyzed 20 volunteers. The researchers measured the activity in the brains of the volunteers as they made choices between food items they would eat later.

These volunteers were asked to indicate how much they would be willing to pay for each snack; with this they determined the subjective value of snack options. After they made their choice, they were asked to report how confident they were that they had made the right decision and selected the best snack.

Prior to this, it was shown that a region at the front of the brain, the ventromedial prefrontal cortex, is important for working out the value of decision options. 

But these findings reveal that the level of activity in this area is also linked to the level of confidence participants placed on choosing the best option. It also highlights that the interaction between this area of the brain and an adjacent area reflects participants' ability to access and report their level of confidence in their choices.

Dr Steve Fleming, a Sir Henry Wellcome Postdoctoral Fellow now based at New York University, explains: "We found that people's confidence varied from decision to decision. While we knew where to look for signals of value computation, it was very interesting to also observe neural signals of confidence in the same brain region."

Dr Benedetto De Martino, a Sir Henry Wellcome Postdoctoral Fellow at UCL, added: "Overall, we think our results provide an initial account both of how people make choices, and also their insight into the decision process."

The study has been published in the journal Nature Neuroscience.