Faculty of Life Sciences, University of Manchester, Manchester, United Kingdom.
Invest Ophthalmol Vis Sci. 2011 Jan 25;52(1):541-8. doi: 10.1167/iovs.10-5910.
To link psychophysical thresholds for blind spot awareness and filling-in with early neural components that underpin these perceptions.
Blind spot dimensions were quantified, after which an intrinsic stimulus (i.e., a rectangular bar of varying length centered within the blind spot) was used to determine blind spot awareness and filling-in for five subjects. Histologic examination of six human retinas at 20-μm intervals from the temporal and nasal neural rims of the optic nerve head out to 1040 μm allowed the quantification of outer nuclear layer thickness, a direct correlate of photoreceptor density.
Blind spot awareness was reported for bar extensions beyond 0.4° to 0.8° from the edge of the blind spot. Partial and total blind spot filling-in were reported between 1.1° and 1.3° and beyond 1.5°, respectively. Histologic measures of ONL thickness were correlated with previously published data of photoreceptor spatial density to determine the percentage of photoreceptor density required to trigger a 75% probability response. Blind spot awareness was achieved by stimulating 43% to 70% of the maximum photoreceptor density. Partial and total filling-in of the blind spot required between 78% and 83% and more than 85% photoreceptor spatial densities, respectively.
A novel intrinsic stimulus has been used to concurrently investigate blind spot awareness and blind spot filling-in. Retinal neural correlates of each visual experience have been quantified. Future computational models will have to integrate bottom-up constraints with long-range cortical receptive field activity and higher order cognitive factors.
将盲点意识和填充的心理物理阈值与这些感知所依赖的早期神经成分联系起来。
量化盲点尺寸后，使用固有刺激（即位于盲点中心的长度不同的矩形条）来确定五个受试者的盲点意识和填充情况。对六个人视网膜进行组织学检查，从视神经头的颞侧和鼻侧神经边缘以 20μm 的间隔进行，直到 1040μm，以量化外核层厚度，这是光感受器密度的直接相关物。
报告了盲点边缘外 0.4°至 0.8°的棒延伸的盲点意识。报告了部分和完全盲点填充，分别在 1.1°至 1.3°和 1.5°以上。ONL 厚度的组织学测量与先前发表的光感受器空间密度数据相关联，以确定触发 75%概率反应所需的光感受器密度百分比。通过刺激 43%至 70%的最大光感受器密度来实现盲点意识。部分和完全填充盲点需要分别达到 78%至 83%和超过 85%的光感受器空间密度。
使用新颖的固有刺激同时研究了盲点意识和盲点填充。量化了每种视觉体验的视网膜神经相关性。未来的计算模型将不得不整合自下而上的约束与远距离皮质感受野活动和更高阶认知因素。
