Do Monkeys Want Audio or Visual Stimuli? Interactive Computers for Choice with White-Faced Sakis in Zoos

Interactive systems were built to give monkeys a choice over when and where to trigger stimuli as a way to control their environment to improve their welfare indices. Typically, systems only support the triggering of one stimulus - either audio or visual. In this study, a system was developed for monkeys that allowed them to choose between multiple auditory and visual stimuli. Utilising this system over several weeks, we found that monkeys would interact and choose between different stimuli, though not significantly, and that sakis triggered audio stimuli twice as much as visual stimuli. The monkeys interacted with audio and visual stimuli differently over time, spotlighting how we can define and measure the interactivity and user experience for monkey-computer interfaces. Furthermore, the monkeys' interactions, while initially increasing, declined over the study period, which indicated a novelty effect. This paper builds upon computer systems for primates by uncovering answers to key questions regarding creating and defining interactive systems according to a user's choices.