Rislove Elizabeth M, Hall Elaine C, Stavros Kara A, Kiorpes Lynne
School of Optometry, University of California, Berkeley, Berkeley, CA, USA.
J Vis. 2010 Oct 22;10(12):25. doi: 10.1167/10.12.25.
Amblyopic humans are known to have a range of spatial vision abnormalities. Prior studies have documented amblyopic deficits in global form perception but have typically used only one set of stimulus parameters. Our aim in this study was to examine the extent and nature of global form perception deficits in strabismic amblyopia using a range of spatial scales and pattern types. Glass patterns are random dot stimuli in which the local orientations of paired dots must be integrated over space to yield a global form percept. We measured coherence thresholds for discrimination of pattern structure in translational (linear) and concentric Glass patterns at three spatial scales in two control and six amblyopic observers. We found that sensitivity to Glass patterns depended on both spatial scale and pattern type in all observers. Participants with a history of abnormal early visual experience showed greater interocular threshold difference when the discrimination was based on translational patterns than when it was based on concentric patterns, and the degree of amblyopic loss was greatest at fine spatial scale. Our results show that the nature and extent of global form vision deficits vary substantially with stimulus parameters and are greatest at fine spatial scales.
已知患有弱视的人存在一系列空间视觉异常。先前的研究记录了弱视患者在整体形状感知方面的缺陷，但通常仅使用一组刺激参数。我们这项研究的目的是使用一系列空间尺度和图案类型，来检验斜视性弱视中整体形状感知缺陷的程度和性质。格拉斯图案是随机点刺激，其中配对点的局部方向必须在空间上整合，以产生整体形状感知。我们在两个对照组和六个弱视观察者中，测量了在三个空间尺度下，平移（线性）和同心格拉斯图案中图案结构辨别所需的连贯阈值。我们发现，在所有观察者中，对格拉斯图案的敏感度均取决于空间尺度和图案类型。有早期视觉经验异常病史的参与者，基于平移图案进行辨别时，两眼间的阈值差异比基于同心图案时更大，且弱视损失程度在精细空间尺度下最大。我们的结果表明，整体形状视觉缺陷的性质和程度会随刺激参数而大幅变化，且在精细空间尺度下最为严重。
