Varella, T. T.; Takahashi, D. Y.; Ghazanfar, A. A.

Active sensing is a behavioral strategy for exploring the environment. In this study, we show that contact vocal behaviors can be an active sensing mechanism that uses sampling to gain information about the social environment, in particular, the vocal behavior of others. With a focus on the real-time dyadic vocal interactions of marmoset monkeys, we contrast active sampling to a vocal accommodation framework which suggests that vocalizations are adjusted for maximizing perceived response probability. We conducted simulations of a vocal accommodation and an active sampling policy and compared them with real vocal exchange data. Our findings support active sampling as the best model for marmoset monkey vocal exchanges. These results suggest a new function for primate vocal interactions in which they are used by animals to seek information from social environments.