Anticipatory modulation as a unifying principle of sensory coding during locomotion

Locomotion modulates the activity of sensory systems in multiple ways: from gain changes in individual neurons to changing interactions in neural populations. These effects are not universal; while movement has a strong influence on sensory coding in rodents, its impact on primates is less prominent. The diversity of effects that locomotion exerts on sensory neurons, as well as disparities between species, raises questions about the existence of universal principles that may underlie sensation during behavior. We propose that sensory systems are modulated in anticipation of systematic changes in stimulus statistics caused by locomotion to maintain an accurate and efficient sensory code across behavioral states. Model neurons optimized to encode stimuli recorded during movement in natural environments predict and reproduce a broad spectrum of experimental observations. The proposed, simple principle of anticipatory modulation reconciles the diversity of ways in which locomotion modulates visual coding in different animal species.