The Spiral After-Effect

The Spiral After-Effect discusses the spiral after-effect of apparent movement. It aims to bring a body of research literature into some compact form for the convenience of students and clinicians in particular, and experimentalists in general. It seeks to outline the main areas of interest in the study of this intriguing illusion and to examine the influence of selected psychophysical, program, and subject factors on its incidence and duration. It also provides a few suggestions for future research. The book begins with an introduction and historical review of studies on the after-effect of apparent movement. Separate chapters then cover stimulus variables and their influence on the incidence and duration of the after-effect; program variables relevant to the incidence and duration of the illusion; the influence of selected observer variables on the incidence and duration of the after-effect; and theoretical explanations of the after-effect. The appendix provides an abstract of the main experiments, findings, and conclusions of the pre-eminent figure in the field of motion aftereffects Dr. G. A. Wohlgemuth who, working between 1905 and 1909, brought together the existing literature up to the period and summarized what was largely nineteenth-century work.