Kiper D C, Kiorpes L
Howard Hughes Medical Institute, Center for Neural Science, New York University, NY 10003.
Vision Res. 1994 Jun;34(12):1575-83. doi: 10.1016/0042-6989(94)90114-7.
Human strabismic amblyopes show deficits in spatial vision that can be revealed in a variety of visual tasks. In particular, they show a reduced sensitivity to contrast for a wide range of spatial frequencies. The ability of strabismic amblyopes to process contrast information at levels well above detection threshold is less well understood and somewhat controversial. In the course of investigating the neural basis of strabismic amblyopia we studied contrast processing both at and above detection threshold in experimentally strabismic monkeys (Macaca nemestrina). First we trained them to perform a contrast detection task and measured their contrast sensitivity for a wide range of spatial frequencies. Then we trained them to discriminate between two gratings that were identical except for their contrast. We show that these monkeys exhibit deficits in both tasks. The deficits in the contrast discrimination task cannot be solely attributed to their deficit at threshold.
人类斜视性弱视患者在空间视觉方面存在缺陷，这在各种视觉任务中都有所体现。特别是，他们在广泛的空间频率范围内对对比度的敏感度降低。斜视性弱视患者在远高于检测阈值的水平上处理对比度信息的能力，目前了解较少且存在一定争议。在研究斜视性弱视的神经基础过程中，我们对实验性斜视猕猴（食蟹猴）在检测阈值及以上水平的对比度处理进行了研究。首先，我们训练它们执行对比度检测任务，并测量它们在广泛空间频率范围内的对比度敏感度。然后，我们训练它们区分两个除对比度外完全相同的光栅。我们发现这些猴子在两项任务中均表现出缺陷。对比度辨别任务中的缺陷不能仅仅归因于它们在阈值水平的缺陷。
