Low- and high-level motion perception deficits in anisometropic and strabismic amblyopia: evidence from fMRI.

摘要: Maximum motion displacement (Dmax) is the largest dot in a random-dot kinematogram (RDK) at which direction of can be correctly discriminated [Braddick, O. (1974). A short-range process apparent motion. Vision Research, 14, 519-527]. For first-order RDKs, Dmax gets larger as size increases and/or density decreases. It has been suggested that this increase reflects greater involvement high-level feature-matching mechanisms and less dependence on low-level detectors [Sato, T. (1998). Dmax: Relations to low- processes. In Watanabe (Ed.), High-level processing, computational, neurobiological, psychophysical perspectives (pp. 115-151). Boston: MIT Press]. Recent findings [Ho, C. S., & Giaschi, D. E. (2006). Deficient maximum amblyopia. 46, 4595-4603; Ho, (2007). Stereopsis-dependent deficits displacement. 47, 2778-2785] suggest "switch" from processing also observed children with anisometropic strabismic amblyopia RDK increased decreased. However, both high- were reduced relative controls. study, we used functional MRI determine motion-sensitive areas may account for control group, RDKs elicited stronger responses (posterior occipital) response (extra-striate occipital-parietal) when activation was compared RDKs. Participants showed same pattern cortical although extent differences than those amblyopia, there almost no difference activity other groups. Differences related amblyogenic subtype.