Pons Carmen, Mazade Reece, Jin Jianzhong, Dul Mitchell, Alonso Jose-Manuel
Department of Biological and Visual Sciences, SUNY Optometry, New York, NY 10036, USA.
Department of Neurological Surgery, University of Chicago Medicine, Chicago, IL 60637, USA.
bioRxiv. 2024 Oct 21:2024.10.17.618707. doi: 10.1101/2024.10.17.618707.
The human eye has a crystalline lens that focuses retinal images at the point of fixation. Outside this fixation region, images are distorted by optical blur, which increases light scatter and reduces the spatial resolution and contrast processed by neuronal pathways. The spectacle lenses that humans use for optical correction also minify or magnify the images, affecting neuronal surround suppression in visual processing. Because light and dark stimuli are processed with ON and OFF pathways that have different spatial resolution, contrast sensitivity and surround suppression, optical blur and image magnification should affect differently the two pathways and the perception of lights and darks. Our results provide support for this prediction in cats and humans. We demonstrate that optical blur expands ON receptive fields while shrinking OFF receptive fields, as expected from the expansion of light stimuli and shrinkage of dark stimuli with light scatter. Spectacle-induced image magnification also shrinks OFF more than ON receptive fields, as expected from the stronger surround suppression in OFF than ON pathways. Optical blur also decreases the population response of OFF more than ON pathways, consistent with the different effects of light scatter on dark and light stimuli and the ON-OFF pathway differences in contrast sensitivity. Based on these results, we conclude that optical blur and image magnification reduce the receptive field sizes and cortical responses of OFF more than ON pathways, making the ON-OFF response balance a reliable signal to optimize the size and quality of the retinal image.
人眼有一个晶状体，可将视网膜图像聚焦在注视点上。在这个注视区域之外，图像会因光学模糊而失真，这会增加光散射，并降低神经通路处理的空间分辨率和对比度。人类用于视力矫正的眼镜镜片也会缩小或放大图像，影响视觉处理中的神经周围抑制。由于明暗刺激是通过具有不同空间分辨率、对比度敏感度和周围抑制的开环和闭环通路进行处理的，光学模糊和图像放大对这两条通路以及明暗感知的影响应该有所不同。我们的研究结果在猫和人类身上为这一预测提供了支持。我们证明，正如光散射导致光刺激扩大和暗刺激缩小所预期的那样，光学模糊会扩大开环感受野，同时缩小闭环感受野。眼镜引起的图像放大也会使闭环感受野比开环感受野缩小得更多，这与闭环通路比开环通路具有更强的周围抑制作用所预期的一致。光学模糊对闭环通路的群体反应的降低也比对开环通路的更大，这与光散射对明暗刺激的不同影响以及开环 - 闭环通路在对比度敏感度上的差异相一致。基于这些结果，我们得出结论，光学模糊和图像放大对闭环通路的感受野大小和皮质反应的降低比对开环通路的更大，使得开环 - 闭环反应平衡成为优化视网膜图像大小和质量的可靠信号。
