A Cognitive Map of a Subjective Value Space During Risky Decision-Making

Poster Session B - Sunday, March 30, 2025, 8:00 – 10:00 am EDT, Back Bay Ballroom/Republic Ballroom

Jake Blumwald¹ (jblumwald@ucdavis.edu), Mark A. Orloff¹, Seongmin A. Park², Phillipe Domenech^3,4,5, Erie D. Boorman¹; ¹University of California Davis, ²Virginia Tech, ³Paris Brain Institute, ⁴INSERM, ⁵CNRS

Individuals make decisions according to subjective valuations of options, integrating multiple attributes into a subjective value signal thought to be encoded by a value coding system. How the brain transforms option attributes into subjective values remains poorly understood. We hypothesize the cognitive mapping system, comprising grid cell representations in the entorhinal cortex (EC) & medial prefrontal cortex (mPFC), may mediate this process when when decisions rely on a cognitive map. We developed a novel risky decision-making task & use computational modeling combined with fMRI to test if grid-like representations of a 2D 'value-space' (comprised of reward amount and probability) are utilized during the decision-making process. Using computational modeling to account for individuals' subjective valuation of options based on cumulative prospect theory, we estimated a distorted 'subjective value' space per individual, and tested for key signatures of the cognitive mapping system for an objectively and subjectively defined cognitive map. FMRI results demonstrate a grid-like representation of decision vectors in individuals' subjective value space of probability and amount in both EC & mPFC. Using representational similarity analysis, we further identify a 2D positional code for individuals' subjective value spaces, again in EC & mPFC. Furthermore, we show that the strength of grid-like representation in EC is correlated with the strength of subjective value representations in two regions, ventromedial prefrontal cortex & posterior cingulate cortex, suggesting the cognitive mapping and value coding system work in tandem. These findings suggest a potential novel mechanism by which individuals construct and compare subjective values for choices.

Topic Area: THINKING: Decision making