Actions as perceptual experiments

How do we know where (and when) things happen? We review evidence that actions operate as experiments that test and recalibrate internal spatial hypotheses. Postsaccadic errors across ∼100,000 daily saccades induce serial dependencies that shift visual localization. During eye-head gaze shifts, the brain compares expected self-generated motion with sensed motion; subtle velocity-gain perturbations bias perception and head kinematics. In locomotion, manipulating optic-flow speed changes walked distance and, in turn, rescales perceived depth. Temporal reproduction shows serial dependence within action but little transfer to visual time perception. Together, these findings support a unifying perspective on visual space perception as a permanent and active probing of our internal predictions about the environment.