A multivariate approach reveals the behavioral templates underlying visual discrimination in rats.

Although rodents are the first-choice animal model in the life sciences, they are rarely used to study higher visual functions. It is unclear to what extent rodents follow complex visual strategies to solve visual object recognition and discrimination tasks [1-5]. We report the performance of rats in a visual discrimination task applying the multivariate "Bubbles" paradigm previously used in highly visual species such as humans, monkeys, and pigeons [6-8]. We demonstrate a relationship between accuracy and local occlusion of stimuli by bubbles, as such revealing the strategies or "templates" that underlie visual discrimination behavior. Performance was guided by relatively simple, screen-centered templates as well as more adaptive templates reflecting context dependency and tolerance for changes in stimulus position. These findings demonstrate the complexity of visual strategies followed by rats and reveal interesting similarities (e.g., potential for position tolerance) as well as differences (overall efficiency of visual processing) compared to primates. In conclusion, this study illustrates the feasibility of investigating visual cognition in rats with multivariate behavioral paradigms, with the ultimate aim to use a comparative approach to explore the anatomical and neurophysiological basis of vision, also for those visual abilities that are traditionally studied in humans and monkeys.