Confidence is important for our daily life decisions. This applies both to conscious and less conscious decisions. When crossing a busy street, for example, we trust in a scenario in which we are not run over. If we consider investing in stocks or securities, we will only do so if our brains can come up with a profitable scenario.
Comparing scenario’s
This is not always obvious, as several scenarios are often feasible. Are you sure that the car in the busy street will not accelerate at the last moment? Is there not a chance that the stock market will collapse if war breaks out in the Ukraine? Our brain calculates different scenarios and chooses the most likely. If many alternatives are conceivable, we make a different choice.
“Our brains are actually doing the same thing as the RIVM”, explains Janneke Jehee. ‘They don't just calculate what the best decision is, but also take alternative scenarios into account. If the number of alternative scenarios is high, we make a different decision.” Laura Geurts adds: “How much confidence we subsequently have in that decision is determined by the number of possible alternatives.”
Brain activity
The researchers studied this with visual information. Subjects were shown something and had to answer questions about it. They had to indicate how much confidence they had in their answers. While they were doing this, their brain activity was measured in an MRI scanner.
The smaller the number of possible alternatives, the more confident people were about their answers. The consideration of scenarios was reflected in brain activity, in areas involved in decision making and confidence. All in all, according to the researchers, this indicates that we derive confidence mainly from the number of scenarios. Rather than, for example, from simple rules of thumb, such as how busy the street is at the moment of crossing.
Learning better with confidence
The mini RIVM in our brains is therefore calculating scenarios all day long. The fact that we base a large part of our confidence on them is useful to know. It can, for instance, support the development of teaching methods or therapies. Jehee: "It is known that many psychiatric disorders are associated with changes in how confident people are about their decisions. We also know that children and adults learn better and faster if they can properly assess their own uncertainty."