Croner L J, Kaplan E
Laboratory of Biophysics, Rockefeller University, New York, NY 10021.
Vision Res. 1995 Jan;35(1):7-24. doi: 10.1016/0042-6989(94)e0066-t.
We studied the receptive field organization and contrast sensitivity of ganglion cells located within the central 80 (radius of 40) deg of the macaque retina. Ganglion cell activity was monitored as synaptic (S) potentials recorded extracellularly in the lateral geniculate nuclei of anesthetized and paralyzed monkeys. Receptive field center and surround regions of magnocellularly-projecting (M) and parvocellularly-projecting (P) cells increase in area with distance from the fovea, with the center radii of M cells being about twice those of neighboring P cells. Peak sensitivities of center and surround regions are inversely proportional to the regions' areas, so that integrated contrast sensitivities (contrast gains) are constant across the visual field, with the gain of M cells being, on average, six times that of P cells. For both M and P cells, the average ratio of surround/center gain is 0.55. Constant gain of P cells across the visual field is achieved by increasing sensitivity to stimuli falling on the peripheral retina to an extent that counteracts the aberrations introduced by the eye's optics.
我们研究了猕猴视网膜中央80度（半径40度）范围内神经节细胞的感受野组织和对比度敏感度。在麻醉和瘫痪的猴子的外侧膝状核中，通过细胞外记录突触（S）电位来监测神经节细胞的活动。大细胞投射（M）细胞和小细胞投射（P）细胞的感受野中心和周边区域面积随离中央凹距离增加而增大，M细胞的中心半径约为相邻P细胞的两倍。中心和周边区域的峰值敏感度与区域面积成反比，因此整个视野的综合对比度敏感度（对比度增益）是恒定的，M细胞的增益平均是P细胞的六倍。对于M细胞和P细胞，周边/中心增益的平均比值均为0.55。P细胞在整个视野中实现恒定增益是通过将对外周视网膜上刺激的敏感度提高到一定程度，以抵消眼睛光学系统引入的像差。
