Being one of the pillars of the cognitive revolution in psychology, information theory provides valuable insights into how the brain functions as an information system in various cognitive functions. In motor control, the body serves as a conduit for information transmission between the mind and the physical world. With this approach, researchers have demonstrated how optimization of information processing enhances movement efficiency and accuracy, with far-reaching impacts on robotics and AI in terms of replicating human motor learning and control. Overall, the information-theoretic perspective provides a comprehensive evaluation framework that allows disparate cognitive functions to be studied under a unified, information-centric paradigm.