The spatial extent of size adaptation effect in peripheral vision

Abstract

It has been shown that prolonged exposure to a certain object size (i.e. size adaptation) alters the subsequent size perception such that the size of the latter appears more dissimilar to the adapted size (Pooresmaeili, Arrighi, Biagi, & Morrone, 2013). However, how much of the visual space is in uenced by the size adaptation at a certain location remains unanswered. Here, in order to investigate the spatial extent of the adaptation effect, we tested the size adaptation effect at the adapted location and various non-adapted locations. In the first psychophysical experiment, we showed a mid-sized adapter stimulus and tested its in uence on subsequent size perception at 5 locations. Results showed that the size perception at non-adapted locations was in uenced by the adapter, although not as much as the effect at the adapted location. In the second experiment, we tested the size aftereffect at 15 different locations and mapped out the perceived size distortions over the visual field. Lastly, in the third experiment, we tested the effect of size adaptation with ring-shaped stimuli and found a substantially large effect just as in the second experiment. These findings overall suggest that the size adaptation does not only have a local effect but also the size perception in consequence of adaptation is being distorted throughout the visual field.