Alpern M, Tamaki R
J Physiol. 1983 May;338:669-91. doi: 10.1113/jphysiol.1983.sp014695.
Foveal dark-adaptation undertaken to test the hypothesis that the excitation of rods causes the desaturation of 'yellow' lights in a 1 degree field traversing the margin of the pupil, fails to exclude that possibility. The desaturation is largest for a 1 degree outside diameter annular test, is still measurable with a 0.5 degree circular disk, but disappears for a 0.29 degree disk. The supersaturation of obliquely incident 501.2 nm test light follows the opposite pattern; it disappears with an annulus and is largest for a 0.29 degree circular field. It is unlikely that rods replace short-wave sensitive cones in the trichromatic match of an obliquely incident test with normally incident primaries. If rods as well as all three cones species are involved, the matches might not be trichromatic in the strong sense. Grassmann's law of scalar multiplication was tested and shown not to hold for the match of an obliquely incident test with normally incident primaries, though it remains valid whenever, both primaries and test strike the retina at the same angle of incidence (independent of that angle). The result in section 3 (above) cannot be due to rod intrusion. It persists (and becomes more conspicuous) on backgrounds (4.0 log scotopic td) which saturate rods. Moreover obliquely incident 'yellow' lights remain desaturated in intervals in the dark after a full bleach, whilst the test field is below rod threshold. The amount of desaturation does not differ appreciably from that normally found. The assumption of the unified theory of Alpern, Kitahara & Tamaki (1983) that the outer segments of only a single set of three cone species (with acceptance angles wide enough to include the entire exit pupil) contain the visual pigments absorbing both the normally incident primaries and the obliquely incident test is disproved by these results. Failure of Grassmann's law is most conspicuous under the conditions for which the changes in saturation upon changing from normal to oblique incidence are greatest and least when the saturation changes are the smallest. Either all unified theories of the Stiles-Crawford effects are wrong or all the effects of oblique incidence operate at a stage in the visual process at which the effects of radiation of different wave-lengths are no longer compounded by the simple linear laws.
在穿过瞳孔边缘的1度视野中，视杆细胞的兴奋会导致“黄色”光去饱和，但这一实验未能排除这种可能性。对于外径为1度的环形测试，去饱和程度最大；对于0.5度的圆盘仍可测量到去饱和，但对于0.29度的圆盘，去饱和现象消失。倾斜入射的501.2纳米测试光的过饱和情况则呈现相反的模式；它在环形测试时消失，而在0.29度的圆形视野中最大。在倾斜入射测试光与垂直入射原色光的三色匹配中，视杆细胞不太可能替代短波敏感视锥细胞。如果视杆细胞以及所有三种视锥细胞都参与其中，那么这种匹配在严格意义上可能不是三色性的。对格拉斯曼标量乘法定律进行了测试，结果表明在倾斜入射测试光与垂直入射原色光的匹配中该定律不成立，不过只要原色光和测试光以相同入射角照射视网膜（与该角度无关），该定律仍然有效。上述第3节中的结果不可能是由于视杆细胞的干扰。在使视杆细胞饱和的背景（4.0对数暗视td）下，该结果依然存在（并且变得更加明显）。此外，在完全漂白后的黑暗间隔中，倾斜入射的“黄色”光在测试视野低于视杆细胞阈值时仍保持去饱和状态。去饱和量与正常情况下发现的量没有明显差异。阿尔珀恩、北原和玉置（1983年）的统一理论假设只有一组三种视锥细胞（其接受角足够宽以涵盖整个出射瞳孔）的外段含有吸收垂直入射原色光和倾斜入射测试光的视觉色素，这些结果证明了这一假设是错误的。在从垂直入射变为倾斜入射时饱和度变化最大的条件下，格拉斯曼定律的失效最为明显；而当饱和度变化最小时，失效则最小。要么所有关于斯泰尔斯 - 克劳福德效应的统一理论都是错误的，要么倾斜入射的所有效应都在视觉过程的某个阶段起作用，在这个阶段不同波长辐射的效应不再由简单的线性定律复合而成。
