In order to keep pace with a complex and ever-changing visual environment, the visual system must combine moment-to-moment sensory evidence with prior expectations that reflect predictable regularities in the environment. Although priors (and other subjective probability distributions) are key to visual perception, they are notoriously difficult to estimate because perception is an inherently private (subjective) experience. In this talk, I will highlight work using large-scale serial reproduction experiments to obtain stable estimates of subjective probability distributions in visual memory. I will also discuss recent work elucidating how neural population activity in the PFC integrates prior expectations with sensory signals during visual perception in macaque monkeys. Time permitting, I will highlight my current work investigating the relation between perceptual representations and emergent communication using the Information Bottleneck (IB) Principle.