Burns S A, Wu S, He J C, Elsner A E
Schepens Eye Research Institute, Boston, Massachusetts 02114, USA.
J Opt Soc Am A Opt Image Sci Vis. 1997 Sep;14(9):2033-40. doi: 10.1364/josaa.14.002033.
Cones show a differential sensitivity to light coming from different portions of the pupil, typically being most sensitive to light from the center of the pupil. We measured the directional properties of the cones across the central 6 deg of the retina, using an optical imaging technique. We find that the cones in the center of the fovea have the broadest tuning. The width of the angular tuning changes rapidly from 0 deg to 1 deg retinal eccentricity, with cones at 1 deg being much more narrowly tuned that the cones in the center of the fovea. Directional tuning of the cones remains relatively constant from 1 deg to 3 deg retinal eccentricity. Receptoral disarray contributes minimally to the measured directional properties of the foveal cones, and there is no evidence of asymmetry between horizontal and vertical retinal locations. There are only small differences among the five subjects in the change in angular tuning of the cones with retinal location. We find that at the foveal center the directional tuning of the cones is limited by the diameter of the cone apertures.
视锥细胞对来自瞳孔不同部位的光表现出不同的敏感度，通常对来自瞳孔中心的光最为敏感。我们使用光学成像技术测量了视网膜中央6度范围内视锥细胞的方向特性。我们发现，中央凹中心的视锥细胞具有最宽的调谐范围。角调谐宽度从0度视网膜偏心率迅速变化到1度，1度处的视锥细胞调谐比中央凹中心的视锥细胞窄得多。视锥细胞的方向调谐在1度到3度视网膜偏心率范围内保持相对恒定。感受器紊乱对视锥细胞测量的方向特性贡献最小，并且没有证据表明视网膜水平和垂直位置之间存在不对称。在五个受试者中，视锥细胞角调谐随视网膜位置的变化只有很小的差异。我们发现，在中央凹中心，视锥细胞的方向调谐受视锥细胞孔径直径的限制。
