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Abstract
We have shown recently that an occipital correlate of the electric phosphene can be recorded by a summation technique. We have named this phenomenon the electrically evoked response (EER) of the visual system. The present report concerns an attempt to locate the retinal cell of origin of the EER. For this purpose we have utilized a strain of rats reported by Bourne, Campbell, and Tansley,4 and by Dowling and Sidman,5 in which the retinal receptors degenerate during the first month of life. By recording from the dura over the visual cortex we have been able to demonstrate that in animals with complete loss of receptor segments and nuclei, the light evoked response (VER) and electroretinogram (ERG) is absent; in these same animals the EER is normal. Together with previously reported findings, this conclusively eliminates the receptor cell as the site of origin of the EER as recorded by us.