In this news, we discuss the Nerve cell activity reveals decision confidence.
Decision making is the mental process of selecting a course from a set of alternatives and it produces a result which can be an action, a recommendation or an opinion.
Every day we make decisions and we are much more confident in some of them than in others. Researchers at Bonn University Hospital have now identified nerve cells in the brain whose activity indicates confidence in decisions.
The results were published in the journal Current Biology.
A total of twelve men and women participated in their experiment. “We showed them pictures of two different snacks, for example a bar of chocolate and a bag of crisps,” explains Professor Florian Mormann from the Epileptology Department. “They were then asked to use a cursor to indicate which of these alternatives they prefer to eat. The more they moved the slider from its central position to the left or right photo, the more confident they were in their decision.
The participants had to judge a total of 190 pairs of different snacks. At the same time, scientists recorded the activity of 830 nerve cells each in the so-called temporal lobe. “We found that the frequency of electrical impulses in some neurons, ie their ‘trigger rate’, changes with increasing decision confidence,” says Mormann’s colleague Alexander Unruh-Pinheiro. “For example, some fired more frequently, the more confident the person tested was in their decision.”
This is the first time that such a correlation between activity and confidence in the decision has been identified. Affected neurons are located in an area of the brain that plays a role in memory processes. “It is possible that we are storing not only the decision we made, but also our confidence in it,” speculates Mormann. “Maybe such a learning process saves us from future bad decisions.”
Ethical reasons generally preclude studying the state of individual neurons in living humans. However, the study participants suffered from a severe form of epilepsy. In this form of the disease, the characteristic seizures always begin in the same region of the brain. One possible treatment therefore consists of surgically removing this epileptic focus. To identify the exact location of the site, doctors from the Epileptology Clinic implant several electrodes in the patient. These are spread over the entire potentially affected area. At the same time, they also provide a better understanding of the functioning of individual nerve cells in the brain.
Researchers at the University of Bonn were originally looking for a completely different phenomenon: When we make a decision, we assign a subjective value to each of the alternatives. “There is evidence that this subjective value is also reflected in the activity of individual neurons,” says Mormann. “The fact that we rather stumbled upon this link between fire behavior and confidence in decisions even surprised us.”
Nerve cell activity reveals confidence in the decision
Neural activity indicates how confident individuals are