Neuronal Adaptation to the Value Range in Macaque Orbitofrontal Cortex

Abstract

Economic choice involves computing and comparing the subjective values of different options. The magnitude of these values can vary immensely in different situations. To compensate for this variability, decision-making neural circuits adapt to the current behavioral context. In orbitofrontal cortex (OFC), neurons encode the subjective value of offered and chosen goods in a quasi-linear way. Previous work found that the gain of the encoding is lower when the value range is wider. However, previous studies did not disambiguate between neurons adapting to the value range or to the maximum value. Furthermore, they did not examine changes in baseline activity. Here we investigated how neurons in the macaque OFC adapt to changes in the value distribution. We found that neurons adapt to both the maximum and the minimum value, but only partially. Concurrently, the baseline response is higher when the minimum value is larger. Using a simulated decision circuit, we showed that higher baseline activity increases choice variability, and thus lowers the expected payoff in high value contexts.