Abstract
We showed previously that children with amblyopia show significant deficits in motion-defined form perception (Giaschi et al., 1992, IOVS). These deficits are found in both the amblyopic and the nonamblyopic fellow eye. Performance on low-level direction-discrimination tasks is often normal in these children (Giaschi et al., 1998, ARVO). The purpose of this study was to examine performance of amblyopes on high-level motion tasks based on attentive tracking. We tested each eye of 8 children with unilateral anisometropic amblyopia (9 to 16 years old) and 20 age-matched controls on 1 low-level motion task and 4 high-level motion tasks. Children with amblyopia showed similar performance to controls in both eyes on the low-level motion coherence task and on two high-level motion tasks: the maximum number of targets that can be tracked in a multiple-item tracking task; and the perception of “long-range” apparent motion in a four-dot quartet display. However, they showed significantly worse performance than controls in both eyes on the maximum speed for tracking a single target, and in visual search for a biological-motion target, two tasks that are linked in other studies to limits of temporal attention (Battelli et al., 2000, VSS; Verstraten et al., 2000, Vis. Research). These results suggest that amblyopia may be accompanied by a loss in both eyes of some aspects of temporal attention. In contrast, a recent report finds deficits of spatial attention in the amblyopic eye of adults with strabismic amblyopia (Sharma et al., 2000, Nature Neuroscience).