03 July 1987
Vol 237, Issue 4810

About The Cover

Computer simulation of the brain's view of the opening passage of the U.S. Constitution. Each point on the image represents the activity of a retinal ganglion cell viewing the corresponding part of the original document. The image is sharp only in the fovea, which is viewing a point several lines below the large word “People.” The illustration shows the rapid decrease in acuity for small features (high spatial frequencies) as a function of distance from the fovea. This effect of the spatial tuning of the nonfoveal retina is much more apparent in viewing printed text, which is dominated by such small features, than in viewing other kinds of scenes. See page 73. [Josh Wallman, Christopher M. Harris, and Michael D. Gottlieb, City University of New York]