Order of Presentation, Duration and Latency of Spiral Aftereffect

Abstract

In Exp. I the duration and latency of contracting and expanding SAE illusions were measured for alternating and consistent orders of presentation with 1-min. intervals between trials. The duration of the illusion was shorter under the alternating order than under the consistent order, and this effect was attributed to the carry-over of neural aftereffects from one trial to the next. In Exp. II order of presentation was again investigated with intertrial interval varied from 1 to 5 min. The results revealed two types of inhibitory effects: (1) a general inhibitory effect produced when one illusion of either type follows another illusion of either type and (2) a specific inhibitory effect which occurs only when successive illusions are of opposite direction. Latency appears to be inversely related to duration.