Levi D M, Harwerth R S, Manny R E
Invest Ophthalmol Vis Sci. 1979 Jul;18(7):714-25.
We have investigated suprathreshold contrast sensitivity and binocular interactions in strabismic and anisometropic amblyopes using a reaction time paradigm. For every spatial frequency, reaction time increased as the grating contrast decreased. At all spatial frequencies and contrast values the reaction times using the amblyopic eye were prolonged compared to the nonamblyopic eye, but most markedly at high spatial frequencies. In the middle range of spatial frequencies, the contrast vs. reaction time function for the nonamblyopic eyes was biphasic, suggesting that two separate mechanisms detect gratings at high and low contrast levels. These functions in deep amblyopia were monotonic, and in shallow amblyopia the break in the functions was present but shifted to lower contrast levels. Binocular interaction experiments showed that binocular summation was absent at all contrast levels, but binocular occlusion was evident at high contrast levels for amblyopic observers.
我们使用反应时范式研究了斜视性和屈光参差性弱视患者的阈上对比敏感度和双眼相互作用。对于每个空间频率，随着光栅对比度降低，反应时增加。在所有空间频率和对比度值下，使用弱视眼的反应时比非弱视眼延长，但在高空间频率时最为明显。在空间频率的中间范围内，非弱视眼的对比度与反应时函数呈双相性，表明有两种不同机制分别检测高对比度和低对比度水平的光栅。深度弱视患者的这些函数是单调的，浅度弱视患者的函数有转折点，但转折点移至较低的对比度水平。双眼相互作用实验表明，在所有对比度水平下均不存在双眼总和现象，但对于弱视观察者，在高对比度水平下双眼遮挡现象明显。
