Abstract
Global motion perception is an important building block of visual development. Here we focus on the development of this ability itself. Specifically, we explore the impact of early visual deprivation on the availability and development of this ability. This issue has both basic and applied implications related to sensitive periods in visual development and prognoses for sight-restoring surgeries late in childhood. Examples of global motion assessment after recovery from extended blindness are scanty (Ellemberg et al., 2002; Fine et al., 2003). As a part of Project Prakash, we studied 8 subjects who were blind for the first 8 to 17 years of life because of very-early onset bilateral cataracts. Global motion perception was assessed by measuring coherence thresholds using random dot kinetograms (Newsome and Paré, 1988). The assessments were conducted 4 months to 2 years post cataract removal. All subjects had above chance global motion coherence thresholds with the performance of some subjects approaching near-normal levels. Evidence for even partial acquisition of global motion coherence is significant in that it shows that even extended periods of blindness starting near birth do not entirely preclude the development of this ability. The present data greatly extends the window of very early onset blindness duration after which acquisition or development of global motion coherence sensitivity is possible.
Meeting abstract presented at VSS 2013