Dissociation of first- and second-order motion systems by perceptual learning

Abstract

Published in final edited form as: Atten Percept Psychophys. 2012 July ; 74(5): 1009–1019. doi:10.3758/s13414-012-0290-3.Previous studies investigating transfer of perceptual learning between luminance-defined (LD) motion and texture-contrast-defined (CD) motion tasks have found little or no transfer from LD to CD motion tasks but nearly perfect transfer from CD to LD motion tasks. Here, we introduce a paradigm that yields a clean double dissociation: LD training yields no transfer to the CD task, but more interestingly, CD training yields no transfer to the LD task. Participants were trained in two variants of a global motion task. In one (LD) variant, motion was defined by tokens that differed from the background in mean luminance. In the other (CD) variant, motion was defined by tokens that had mean luminance equal to the background but differed from the background in texture contrast. The task was to judge whether the signal tokens were moving to the right or to the left. Task difficulty was varied by manipulating the proportion of tokens that moved coherently across the four frames of the stimulus display. Performance in each of the LD and CD variants of the task was measured as training proceeded. In each task, training produced substantial improvement in performance in the trained task; however, in neither case did this improvement show any significant transfer to the nontrained task.This work was supported in part by NSF Award BCS-0843897 to Dr. Chubb and in part by Award Number RO1NS064100 from the National Institutes of Health, National Institute of Neurological Disorders and Stroke to Dr. Vaina. (BCS-0843897 - NSF; RO1NS064100 - National Institutes of Health, National Institute of Neurological Disorders and Stroke)Accepted manuscrip