ISSN:
1432-1106
Keywords:
Visual acuity
;
Cones
;
Ganglion cells
;
Striate cortex
Source:
Springer Online Journal Archives 1860-2000
Topics:
Medicine
Notes:
Summary Density of cones and ganglion cells was studied in horizontal sections of retina in the rhesus monkey (Macaca, mulatta) and the squirrel monkey (Saimiri sciureus). The lower angular density of cones in the fovea of Saimiri correlates with its visual acuity, which is poorer than that of Macaca (0.74 and 0.65 min of arc respectively). Cone density falls more steeply with angular eccentricity from the fovea in Saimiri, in accordance with its relatively poorer peripheral acuity. Comparable results were obtained with retinal ganglion cells, but the comparisons at the fovea itself are more difficult because of the lateral displacement of these elements in the foveal region. The cortical magnification of the visual field (that is, the number of mm of cortex per degree of visual field) is lower for both the foveal and parafoveal representations at the striate cortex in Saimiri. This was correlated with its poorer foveal and parafoveal acuity. It was shown that with increasing eccentricity from the fovea, the fall in the magnification of the visual field at the striate cortex is approximately proportional to the decrease in ganglion cell density at the retina. The results of this study, in which acuity and topography of the visual system are compared in two species of monkey, are consistent with the view that both retinal topography, and the cortical magnification of the visual field, are closely related to visual acuity.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00235053
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