Subjective value, not a grid-like code, describes neural activity in ventromedial prefrontal cortex during decision-making
Lee, S., Yu, L. Q., & Kable, J. W.
Across numerous studies, ventromedial prefrontal cortex (vmPFC) activity has been found to correlate with subjective value during value-based decision-making. Recently, however, vmPFC has also been shown to reflect a grid-like code used for navigation through physical and conceptual space. This raises the possibility that such a grid-like code could broadly underlie vmPFC’s role in complex cognition and, specifically, may be used for comparing options in decision-making. Here, we first show that, in theory, a grid-like code could account for vmPFC activity previously attributed to subjective value. We then test for grid-like modulation in a large fMRI dataset of intertemporal choice. Here, however, we find that the grid-like model fails confirmatory tests and that instead subjective value provides the better description for vmPFC responses. Our results constrain the tasks for which grid-like modulation is observed in vmPFC and suggest that vmPFC might implement the most useful code for the current task.