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.
Acknowledgments
We thank H. Schoknecht for help with animal training and S. Ballesta, W. Shi, and E. Bromberg-Martin for comments on earlier versions of the manuscript. This work was supported by the National Institutes of Health (grant number R01-MH104494 to CPS and grant number F31-MH107111 to KEC).
Footnotes
Conflict of interest: None