Summation of Potentials in the Chicken Electroretinogram

¹ From the Walter Reed Army Institute of Research, Walter Reed Army Medical Center, Washington, D. C.

An electroretinogram was found only for the first flash of a series of flashes alternating between two separate locations on the exposed chicken retina. This was still true when a septum separated the two locations, therefore, excluding the possibility that nonfocal light might prevent successive activities by providing a constant illumination of the entire retina during the alteration of exposures. Further observations showed that the retinal areas were not inhibited, but were continually active and that with certain electrode placements and exposure rates, electrical summation concealed the individual contributions of each focal area.