Current models of motion perception depend on unidirectional motion-sensitive mechanisms that provide local inputs for complex pattern motion, such as optic flow. To test the generality of such models, we asked observers to compare the speed of radial gratings with the translational speed of vertical gratings. The speed of the radial gratings was consistently overestimated by 20-60% relative to...

vances ever closer to the post-war horizon. With Victory will come the day when the scientific instruments and processes of war will turn abruptly to peace. Machines and tools, as well as industrial and economic thinking, will be converted quickly from the demands of war to the needs of peace. Industry will be called upon to relieve the strains of war with utmiost speed by ministering anew to h...