How are decision processes in the human brain examined?

Taking a decision means weighing up information about the potential options in some way. Therefore, the Research Group Neurocode is developing decision tasks that allow the researchers to control precisely which pieces of information are relevant for a decision and which experiences study participants have made with the consequences of a decision before.

In most studies, brain data are recorded via magnetic resonance imaging (MRI) while the participants are working on such decision tasks. The researchers’ central questions are: How is relevant information and previous experience processed in the brain while the decision is being taken? For example, are individual experiences recalled or is there only some calculation of how a certain choice worked out on average? Addressing this question requires use of modern analysis methods from statistics and machine learning that allow to decode the signals in the brain data. One of the difficulties is that human brain activity cannot be measured directly in MRI, it can only be measured via blood flow.

The second methodological challenge is the interpretation of the statistical results. For example, why are certain experiences recalled while others are not? In order to answer these questions, the researchers test computer models that apply different algorithms to solve the same decision tasks as the human participants. The predictions of these models are then compared to the results of the behavior and brain data analysis.

The combination of the methods described above represents the classical repertoire of an emerging research discipline, namely computational cognitive neuroscience.