Abstract
Visual motion plays a fundamental role in our ability to interpret visual scenes. Previous findings suggest that dynamic information in visual stimuli greatly improves interpretability over still images, especially under conditions of reduced visual acuity. The importance of motion is the motivation for characterizing global motion sensitivity in children who have experienced prolonged periods of visual deprivation prior to treatment. Here, we report results from eighteen children who received treatment for bilateral congenital cataracts several years after birth. We examined their sensitivity to global motion at multiple time points post-operatively. The stimuli consisted of limited life-time kinematograms. Each trial comprised a two-second video of dots moving at a speed of 18° s-1. The field of view was 20 degrees by 20 degrees of visual angle and contained 300 black dots against a white background in each frame. A certain percentage of the dots moved either upwards or downwards, while the remainder of the dots moved in random directions. A staircase procedure was used to determine the subjects’ coherence thresholds. We partitioned the participants into two groups: those who could perform the task pre-operatively and those who could not. For the participants who could perform the task pre-operatively, the motion coherence thresholds remained relatively stable even after sight onset. For the remainder of the participant group, significantly impaired pre-operative vision had rendered them unable to perform the task prior to surgery. After first eye surgery, this subgroup showed significant improvements in performance. Their thresholds after surgery were comparable to the coherence thresholds of the other, less impaired, group. Performance on the global motion task did not correlate with visual acuity or age.