Abstract
We examined the effect of duration of stimuli on the grid-type extinction illusion. A white disc with black edge was presented at an intersection (intersection condition) or near an intersection (alley condition) of gray alleys on black background or was presented on a unique black or gray background (background condition). Experiment 1 examined the effects of duration of the stimuli and retinal eccentricity of the disc on the extinction illusion. Experiment 2 examined the effect of the visual field of stimuli on the extinction illusion. The subjects' task was reported the number of perceived white discs. Two experiments showed the following results in the intersection condition. (1) The frequency that the disc was perceived decreased as the duration of the stimuli increased, if the duration was over 1000ms. (2) The frequency that the disc was perceived decreased as retinal eccentricity increased. (3) The disc presented in the upper visual field was perceived less frequently than that in the lower visual field, when the duration was 200ms; there was no anisotropy when the duration was 6000ms. These results showed that the grid-type extinction illusion depends on the duration and the retinal eccentricity.
