Logical empiricism and the standard view in the philosophy of science made a strict separation between the logic of science and the empirical study of cognitive processing as it is described by psychology. Kuhn rejected this strict separation and used the results of the nascent cognitive psychology, but also from Gestalt psychology to evaluate and criticize the claims of the standard conception in philosophy of science (as he rejected the separation of the logic of science from sociology and history of science). Already in his unpublished Lowell lectures (1951) Kuhn used such a naturalistic approach and developed it further in The Structure of Scientific Revolutions (1962). Based on this naturalistic approach to philosophy of science and the new results of psychology, Kuhn gave new answers to the question of the relation of theory and observation, but also to the question of conceptual changes and the development of new scientific insights. While the logical empiricists analyzed the logical relations between the theoretical and the observational vocabulary letting aside the psychology of perception, Kuhn used the results of cognitive psychology to contest the independence between theory and observation. The psychology in the 50s strongly suggested the idea, that perceptual processes are penetrated by beliefs and conceptual content. Besides Gestalt psychology, the so called “new look” in psychology (e.g. Jerome Bruner) influenced theory-ladenness and seemed to empirically confirm it. Gestalt psychology suggested that new conceptual structures and patterns are gained through sudden insight and permit a new organization of what we see. We will investigate how this psychological research shaped Kuhn´s conception of scientific revolutions in Structure and will evaluate the conclusions Kuhn drew from psychology.