Visual Acuity and the Balance between Receptor Density and Ganglion Cell Receptive Field Overlap

摘要

Visual acuity has been analyzed in terms of the responses of the retinal ganglion cells to different stimuli within their receptive field. The analysis includes not only the relation of the response to the receptor matrix, but also to the neural processing within the retina. A discussion is given of the different methods of analyzing the receptive fields: sensitivity profiles and Ricco field (area x intensity) plots, and displacement sensitivity (the response to a small stimulus plot switched between two positions just touching each other). The difficulties with each of these methods of analyzing the receptive field are illustrated with experimental data. The experimental data also indicates that the blue cone system may not contribute to visual acuity, possibly due to the neural organization of the receptive field, rather than to the small number of blue receptors. The present data indicates that in the cat area central is the average ganglion cell receptive field size is so large that through overlap, each retinal locus must be connected to at least 15 receptive field centers. (Author)