title: Low-level processing deficits underlying poor contrast sensitivity for moving plaids in anisometropic amblyopia.
abstract: Many studies using random dot kinematograms have indicated a global motion processing deficit originated from extrastriate cortex, specifically middle temporal area (MT) and media superior temporal area (MST), in patients with amblyopia. However, the nature of this deficit remains unclear. To explore whether the ability of motion integration is impaired in amblyopia, contrast sensitivity for moving plaids and their corresponding component gratings were measured over a range of stimulus durations and spatial and temporal frequencies in 10 control subjects and 13 anisometropic amblyopes by using a motion direction discrimination task. The results indicated a significant loss of contrast sensitivity for moving plaids as well as for moving gratings at intermediate and high spatial frequencies in amblyopic eyes (AEs). Additionally, we found that the loss of contrast sensitivity for moving plaids was statistically equivalent to that for moving component gratings in AEs, that is, the former could be almost completely accounted for by the latter. These results suggest that the integration of motion information conveyed by component gratings of moving plaids may be intact in anisometropic amblyopia, and that the apparent deficits in contrast sensitivity for moving plaids in anisometropic amblyopia can be almost completely attributed to those for gratings, that is, low-level processing deficits.
authors.affiliation: CAS Key Laboratory of Brain Function and Diseases and School of Life Sciences, University of Science and Technology of China, Hefei, People's Republic of China.
authors.forename: Yong
authors.initials: Y
authors.lastname: Tang
authors.forename: Linyi
authors.initials: L
authors.lastname: Chen
authors.forename: Zhongjian
authors.initials: Z
authors.lastname: Liu
authors.forename: Caiyuan
authors.initials: C
authors.lastname: Liu
authors.forename: Yifeng
authors.initials: Y
authors.lastname: Zhou
mesh_terms: D000328:Adult; D000550:Amblyopia / Q000503:physiopathology*; D015350:Contrast Sensitivity / Q000502:physiology; D004192:Discrimination, Psychological / Q000502:physiology; D006801:Humans; D008962:Models, Theoretical; D009039:Motion Perception / Q000502:physiology; D009483:Neuropsychological Tests; D010364:Pattern Recognition, Visual / Q000502:physiology; D010468:Perceptual Disorders / Q000503:physiopathology*; D013028:Space Perception / Q000502:physiology; D014796:Visual Perception / Q000502:physiology*; D055815:Young Adult