Perceptual learning of apparent motion is mediated through ON- and OFF-pathways in human vision

We document the performance of 26 human observers practicing a motion discrimination task in foveal vision. Two blocks of 1960 apparent motion stimuli each were presented in succession. Stimuli in the two blocks were tailored to activate either the ON-pathway (ON-stimulus) or the OFF-pathway (OFF-stimulus). Initial performance of about half of the subjects was rather weak but improved with practice. Initial performance of the other subjects remained unaffected for the first block. Once performance had improved in one of the tasks it transferred to the other tasks. Improvement in performance to the ON-stimulus was found to extend over many more presentations than that to the OFF-stimulus