Awareness and Filling-in of the Human Blind Spot: Linking Psychophysics with Retinal Topography

作者：Abadi Richard V^*; Jeffery Glen; Murphy Jonathan S

来源：Investigative Ophthalmology & Visual Science, 2011, 52(1): 541-548.

DOI：10.1167/iovs.10-5910

PURPOSE. To link psychophysical thresholds for blind spot awareness and filling-in with early neural components that underpin these perceptions.
METHODS. 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-mu m intervals from the temporal and nasal neural rims of the optic nerve head out to 1040 mu m allowed the quantification of outer nuclear layer thickness, a direct correlate of photoreceptor density.
RESULTS. Blind spot awareness was reported for bar extensions beyond 0.4 degrees to 0.8 degrees from the edge of the blind spot. Partial and total blind spot filling-in were reported between 1.1 degrees and 1.3 degrees and beyond 1.5 degrees, 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.
CONCLUSIONS. 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. (Invest Ophthalmol Vis Sci. 2011;52:541-548) DOI:10.1167/iovs.105910

• 出版日期2011-1