能量、量子和视觉。

ENERGY, QUANTA, AND VISION.

机构信息

Laboratory of Biophysics, Columbia University, New York.

出版信息

J Gen Physiol. 1942 Jul 20;25(6):819-40. doi: 10.1085/jgp.25.6.819.

DOI:10.1085/jgp.25.6.819

PMID:19873316

原文链接:https://pmc.ncbi.nlm.nih.gov/articles/PMC2142545/

Abstract

Direct measurements of the minimum energy required for threshold vision under optimal physiological conditions yield values between 2.1 and 5.7 x 10(-10) ergs at the cornea, which correspond to between 54 and 148 quanta of blue-green light. 2. These values are at the cornea. To yield physiologically significant data they must be corrected for corneal reflection, which is 4 per cent; for ocular media absorption, which is almost precisely 50 per cent; and for retinal transmission, which is at least 80 per cent. Retinal transmission is derived from previous direct measurements and from new comparisons between the percentage absorption spectrum of visual purple with the dim-vision luminosity function. With these three corrections, the range of 54 to 148 quanta at the cornea becomes as an upper limit 5 to 14 quanta actually absorbed by the retinal rods. 3. This small number of quanta, in comparison with the large number of rods (500) involved, precludes any significant two quantum absorptions per rod, and means that in order to produce a visual effect, one quantum must be absorbed by each of 5 to 14 rods in the retina. 4. Because this number of individual events is so small, it may be derived from an independent statistical study of the relation between the intensity of a light flash and the frequency with which it is seen. Such experiments give values of 5 to 8 for the number of critical events involved at the threshold of vision. Biological variation does not alter these numbers essentially, and the agreement between the values measured directly and those derived from statistical considerations is therefore significant. 5. The results clarify the nature of the fluctuations shown by an organism in response to a stimulus. The general assumption has been that the stimulus is constant and the organism variable. The present considerations show, however, that at the threshold it is the stimulus which is variable, and that the properties of its variation determine the fluctuations found between response and stimulus.

摘要

在最佳生理条件下，阈下视觉所需的最小能量的直接测量值在角膜处产生 2.1 到 5.7 x 10(-10) 尔格的值，相当于 54 到 148 个蓝绿光量子。
这些值是在角膜处的。为了得到有生理意义的数据，它们必须校正角膜反射，其值为 4%；校正眼内介质吸收，其值几乎正好是 50%；校正视网膜传输，其值至少是 80%。视网膜传输是从前人直接测量值和视紫红质的吸收光谱与暗视力发光函数之间的新比较中得出的。经过这三次校正，角膜处 54 到 148 个量子的范围上限成为视网膜棒状细胞实际吸收的 5 到 14 个量子。
与所涉及的大量棒状细胞（500 个）相比，这个小数量的量子排除了每个棒状细胞吸收两个量子的任何显著吸收，这意味着为了产生视觉效果，每个视网膜棒状细胞必须吸收一个量子。
由于单个事件的数量如此之小，它可以从光闪烁强度与可见频率之间关系的独立统计研究中得出。这些实验给出了视觉阈限所涉及的关键事件数量为 5 到 8 的值。生物变异不会从根本上改变这些数字，因此，直接测量值和统计考虑值之间的一致性是有意义的。
这些结果阐明了生物体对刺激的波动的性质。一般的假设是刺激是恒定的，而生物体是可变的。然而，目前的考虑表明，在阈限处，是刺激在变化，其变化的性质决定了在响应和刺激之间发现的波动。