Signatures of visuospatial information foraging during learning of complex environments

Abstract

AbstractMany real world environments contain latent features that animals must learn in order to accomplish their goals. Animals often learn these environments over sequences of choices, but the behavioral mechanisms underlying this complex cognitive competence remain poorly characterized. We investigate this sophisticated behavior in two primate species, humans and macaque monkeys, with a task in which subjects searched for shapes hidden on a grid. Both primate species were adept learners, quickly learning the subset of shapes out of the numerous possibilities. Subjects tended to select tiles earlier in trials that were informative in the past about the hidden shape than those that were rewarding. In addition, we found a surprising signature of foraging behavior over sequences of choices during trials, with human subjects searching local areas of the board until information dropped below the average across all choices, at which time they jumped to a different part of the board. This pattern of choices was not evident for rewards in humans. In contrast, the sequences of choices of monkeys were equally well-described as information or reward foraging. Finally, the rate at which humans learned shapes could be predicted by how well their choice sequences matched foraging behavior. These findings suggest that humans are more tuned to the search for information than reward than monkeys and that foraging competence predicts the capacity to learn complex environments.