Interaction of Successive Photic Stimuli in the Human Retina
1955 年 63 巻 1 号 p. 9-17
詳細
1955 年 63 巻 1 号 p. 9-17
By the method of electrostimulation, the cone- and the rod-proc-esses following two successive flashes of white light were separately investigated in the human retina.
1) The cone- and rod-responses to two flashes, conditioning and testing, are in shape almost identical with their responses to the testing flash alone, but the magnitudes of the responses are greater for the two flashes than for the single. This phenomenon is called summation.
2) For summation to occur, the intensity of the conditioning stimulus relative to that of the testing is important. No summation occurs at all when the conditioning stimulus is weaker than the testing.
3) When the interval between two flashes is shorter than 1.5 seconds, inhibition occurs, instead of summation. At intervals longer than 2 seconds the degree of summation is almost constant irrespective of the interval. Summation can still be seen at such a long interval as 20 seconds.
4) The degree of summation is greater for the rod-process than for the cone-process.
We are greatly indebted to Prof. K. Motokawa for his many valuable discussions and kind guidance.
