INTERROGATING SUBJECTIVE VALUE AND CONFIDENCE THROUGH BEHAVIOR AND LARGE-SCALE NEURAL RECORDING

Adaptive behavior relies on external cues and internal variables such as subjective value and belief. We examine reward-related processing and decision confidence in rodents using a head-fixed approach, which allows precise measurement of neural activity and behavior. We performed wide-field calcium imaging of the dorsal cortex in head-fixed mice during a classical conditioning task. Auditory cues predicted reward with varying probabilities, and animals were tested under different levels of thirst. Reward-predicting cues elicited widespread cortical activity even in sated conditions with little licking. This activity was absent in naïve animals, suggesting that it reflects learned predictions. Cue- and outcome-related signals were distributed across frontal to parietal cortical regions and were modulated by physiological condition in ways not fully explained by movement alone. These results suggest that subjective value is represented as a large-scale cortical variable integrating learned predictions with internal context. We also developed a confidence-reporting task for head-fixed rats. Rats performed a visual discrimination task in which they moved a cursor using their forepaws. After making a choice, animals maintained that choice for a variable duration before terminating it to start the next trial, and this duration served as a behavioral measure of confidence. Trained rats showed clear outcome-dependent differences in this duration, indicating stable confidence-related behavior. We are also analyzing facial expressions as an additional behavioral readout. Together, these results show that rodent behavioral tasks combined with neural measurements provide a framework for studying how internal variables interact with external cues across neural scales.