First published in 1978. In this book the author has attempted to present a systematic theoretical and factual account of the role of higher mental processes in human learning and memory, and certain aspects of the psychology of perception and language. The major orienting theme of the book is its dual emphasis on nonverbal imagery and verbal processes (inner speech) as memory codes and mediators of behavior. Based on recent experimental evidence, the conceptual approach in a sense represents an integration of pre-behavioristic and behavioristic views concerning the nature of thought. The book is intended both as a textbook and as a theoretical monograph.