Xuefei Yu¹, Atul Gopal¹, Okihide Hikosaka¹; ¹NIH

Value can originate from different sources, such as being associated with specific objects or locations. While extensive research has explored the neural underpinnings of object and location value processing, the precise brain regions, and mechanisms through which these distinct value sources are processed and integrated to motivate actions in non-human primate remain unclear. In this study, we trained two macaque monkeys to perform two value association tasks: an object value task, where objects were associated with high or low rewards, and a location value task, where value was linked to the location where objects were displayed. After training, both monkeys successfully established value associations in both tasks. This was evidenced by faster saccadic eye movements toward high-value object and locations, as well as a preference for high-value conditions in choice behavior. Neuronal population responses in the primate Frontal Eye Field (FEF) showed significant modulation based on value associations. Among the neuronal population, over half encoded a single source of value (either object or location), while a subset of neurons encoded both object and location values. The separation of object value signals emerged approximately 100ms after object onset, whereas location value signals appeared before target onset, indicating stronger anticipatory modulation for location value. These findings suggest that object and location values partially converge in the FEF, supporting a flexible coding scheme that accommodates both integrated and distinct encoding of object and location values.