Trained visual experts often rapidly perceive things that elude novices, but how? How does experience tailor perception to support skilled performance? These are important questions, both theoretically and in practice as visual experts such as radiologists or security personnel perform tasks that contribute daily to public health and safety. To provide answers, this project integrates knowledge across distinct research areas to propose and rigorously test a new, mechanistic framework for understanding how experience alters perception to support skilled visual processing. The knowledge gained will inform future developments of both training programs fostering transitions from novice to expert and computer systems aiding expert performance.