International Journal of Comparative Psychology

The connection between reduced reinforcement probability and increased behavioral variability hasbeen well established in recent years (Gharib, Gade, & Roberts, 2004; Stahlman, Roberts, & Blaisdell, 2010). Researchers have hypothesized that this relationship is an adaptive one - it is beneficial for animals to increase behavioral variability in response to low likelihood of success,because this increase in variability potentially allows them to discover new behavioral options that are more highly rewarded. We conducted a study to investigate the relationship between behavioral variability and reward probability in an ecologically valid experimental task. We trained rats tosearch for hidden food in the presence of either of two landmarks, each that signaled a different likelihood of reward (i.e., HI and LO). Variation in locations searched was higher in the presence ofthe LO probability landmark. These results build on prior findings that reward expectation drives behavioral variability.