title: Altered global shape discrimination in deprivation amblyopia.
abstract: To assess the effect of deprivation amblyopia on global shape discrimination, sensitivity to radial deformation of circular patterns was assessed in patients treated for congenital (N=7) or developmental (N=1) cataracts. Elevation in radial deformation threshold was dependent on circular contour frequency and the depth of amblyopia. Analysis of thresholds expressed as Weber fractions indicated a shift in global integration to a larger scale. In a pedestal experiment, equivalent intrinsic noise increased in proportion to the depth of amblyopia. The results suggest neural undersampling in V1 and/or higher visual cortical areas in deprivation amblyopia and a possible role for neural disarray.
authors.affiliation: Retina Foundation of the Southwest, 9900 North Central Expressway, Suite 400, Dallas, TX 75231, USA.
authors.forename: Brett G
authors.initials: BG
authors.lastname: Jeffrey
authors.forename: Yi Zhong
authors.initials: YZ
authors.lastname: Wang
authors.forename: Eileen E
authors.initials: EE
authors.lastname: Birch
mesh_terms: D000293:Adolescent; D000328:Adult; D000550:Amblyopia / Q000503:physiopathology*; D002386:Cataract / Q000503:physiopathology; D002648:Child; D015350:Contrast Sensitivity / Q000502:physiology; D004192:Discrimination, Psychological / Q000502:physiology; D005260:Female; D005556:Form Perception / Q000502:physiology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D010364:Pattern Recognition, Visual / Q000502:physiology