PERCEPTION OF MOTION AND CHANGING FORM: A study of visual perception from continuous transformations of a solid angle of light at the eye

It is shown how geometrically changing projections of objects which move and/or change their shape carry no specific information about form and three‐dimensional motion. How, then, does the visual apparatus produce specific percepts from such non‐specific changing stimuli? By applying an analogue computer technique, changing projections of artificial objects are generated on a CRT screen. These projections are fed into the eye by means of an optical device where they form a continuously changing solid angle of homogeneous light. The main conclusion is that it is a principle of perceptual three‐dimensionality which gives specificity to the percepts. Preliminary statements of principles for prediction of perceived motion in depth from a given change in proximal stimulus are presented.