We need to measure the "goodness" of each policy at the group and societal level to make our society free and fair. However, it is known that such an index cannot be successfully created without methods for comparing the well-being (or utility) of different people (Arrow's impossibility theorem; Arrow, 1963). It is also known that it is impossible to compare utility across individuals using classical methods based solely on behavioral data. In our project, we propose methods to measure well-being in an interpersonally comparable manner by combining various physiological indices (Plan 3-1).

In addition, we are strengthening our MEG research system to clarify the neural circuit dynamics of human pleasure and aspiration, and have human MEG and marmoset ECoG experiments on "sense of self of agency" and MEG experiments on "narrative self" underway (Issue 3-2).

(1) Quantification of the intensity of pleasure using brain indices

• We determined the direction for the development of a technique for reading utility with high accuracy (multi-echo fMRI imaging, analysis using generative models).
• We are using an independent database (ABCD study) to analyze the activity of brain regions that we have identified as correlated with utility prediction error (Matsumori et al., 2021).
• In order to reveal the dynamic process by which utility is computed in the brain at high temporal resolution, we determined the design of the utility task for the MEG experiment.