Reduced food accessibility enhances value-based decision-making in rats

Abstract

Finding nutrients regularly is critical for survival; therefore, most animals invest a large portion of their time and energy in securing access to food. Food acquisition activates the brain's reward system, enhancing motivation and thereby increasing chances to succeed again in the future. However, little is known about the effect of food accessibility on cognition. We hypothesize that reducing food accessibility by requiring laboratory animals to get it with effort, will expose them to daily learning challenges, enhance reward system engagement and consequently have a positive impact on cognitive performance. To test whether effortful access to food confers cognitive benefits, one group of rats was housed with a food dispenser specifically designed to reduce food accessibility (Low Accessibility, LA). The comparison group had free access to food at any time (High Accessibility, HA). Both groups were trained in a value-based task in which they were required to choose between two options and, through trial and error, learn which option was more likely to deliver a reward. We found that both groups learned the task structure similarly. However, the LA group showed a higher proportion of optimal choices throughout training, indicating better task performance. We also found that LA rats were more sensitive to the outcomes of previous decisions. Collectively, our findings suggest that reducing food accessibility improves value-based decision-making, potentially by increasing sensitivity to action outcomes, highlighting a previously underappreciated link between food acquisition demands and cognitive performance.