Theoretical definitions describe the underlying mechanisms of learning. They identify ‘the nature’ of learning. Some of the theoretical definitions are physiological in nature. Hull defined learning in terms of ‘receptor-effector’ connections. Bugelski defined learning as the process of formation of relatively permanent neural circuits.
Cognitive psychologists define learning as a reorganization of the perceptual, psychological, and behavioral world of the learner. Kretch and Crutchfield (1948) defined learning as a reorganization of the cognitive field. According to cognitive psychologists, we do not learn a particular response; we learn the relationships between objects, events, concepts, and principles. Through learning, we discover new relations among objects, events, and responses.