PERCEPTUAL-LEARNING IN SEEING FORM FROM MOTION

Some perceptual tasks, such as global stereopsis, have been shown to i mprove with practice. Paradigms that involve such 'perceptual learning ' have been exploited to learn more about the nature and sites of thes e perceptual tasks in the brain and about plasticity in the adult cent ral nervous system. We found that seeing structure from global motion in some kinematograms composed of tilted line elements required a peri od of learning. However, such learning was specific neither to the ori entation of the line elements nor to the direction of global motion, e ven though detection of these line elements and the direction of motio n was necessary for seeing the global structure in these kinematograms . Our results suggest that the neural site of deriving form from motio n is beyond the level of individual motion and pattern detectors. In b oth its nature and locus along the hierarchy of the visual system, thi s learning is quite different from other types of perceptual learning reported so far.