Realistic, everyday rewards contain multiple components. An apple has taste and size. However, we choose along a single dimension, preferring some apples more or less than others. Likewise, reward signals in individual neurons vary along a single dimension; they are higher or lower. Using...

Decisions can be risky or riskless, depending on the outcomes of the choice. Expected Utility Theory describes risky choices as a utility maximization process: we choose the option with the highest utility, which we compute considering both the value of the option and its associated risk....

Rewarding choice options typically contain multiple components, but neural signals in single brain voxels are scalar and primarily vary up or down. In a previous study, we had designed reward bundles that contained the same two milkshakes with independently set amounts; we had used psychophysics...