Max Wertheimer on seen motion: Theory and evidence

Summary Max Wertheimer, the chief founder of an experimentally based Gestalt psychology, conducted his pioneering studies in motion perception on new theoretical grounds. Since the influence of this approach may be greater in today's cognitive psychology than it has ever been during the half-century of introspectionism and radical behaviorism, it is appropriate to review the actual roots of Wertheimer's (1912) seminal publication and his continuing research on apparent and real motion perception in the light of past and recent work. Illustrative examples, especially of Wertheimer's early research, are provided in this paper. The implications of his experimentation and biopsychological theorizing are still of major interest for present psychological inquiry. Nevertheless, the need for more future systematic comparative research on motion perception must be emphasized. The Epilogue of this paper examines why important parts of Wertheimer's experimental contributions to psychology may have been underrated or neglected by many contemporary psychologists.Some of the issues dealt with here are treated at length in a three-part laudatio (Sarris, 1987a, b, 1988a). When this article was prepared for print, its original title, Max Wertheimer on Seen Motion: The Significance of Sound Experimentation for Present and Future Research, as presented at the Wertheimer Memorial Symposium, was changed to the present title. Under the present title, a brief version of this paper was presented at the APA Convention, New Orleans, Louisiana, USA, August 11–15, 1989.I am grateful for the comments and cooperative help provided by Carl F. Graumann, Michael W. von Grünau, Eckart Scheerer, and Michael Wertheimer.