Which theory of learning has found that knowledge of internal processes is crucial to the understanding of learning?

Cognitive theory treats learning as a change in internal mental processes such as perception, memory, thinking and insight, not merely outward behaviour.

Stimulus-response theory reduces learning to observable bonds between a stimulus and a response, leaving out internal cognition.

Operant conditioning theory of B.F. Skinner explains behaviour through reinforcement of its consequences, again external.

Classical conditioning theory of Ivan Pavlov pairs a neutral stimulus with a natural one to form a conditioned response.

Jean Piaget and the Gestalt school are the leading cognitive theorists of learning.

Wolfgang Kohler's insight learning shows a sudden internal restructuring of a problem, a purely cognitive event.