[Binocular summation in the perception of Landolt-ring presented at brief durations (author's transl)]

Landolt-ring identification accuracy of brief durations was determined under monocular presentation. Dichopic presentation to corresponding retinal areas was studied when the same Landolt-ring was presented simultaneously and successively. Both simultaneous and successive dichopic presentation gave identification accuracy significantly above the level expected from two independent chances to perceive at SOAs shorter than 60 msec. Performance under dichopic simultaneous stimulation to non-corresponding areas was slightly lower than that predicted level. Identification performance under monocular successive presentation was better than that under dichopic successive presentation to corresponding areas though these conditions were given the same amount of energy entering the visual system. Laterality and anisotropy in the perception of Landolt-ring were also considered in connection with binocular summation.