Visual body size adaptation and estimation of tactile distance

Abstract

Estimating the size of bodies is crucial for interactions with physical and social environments. Body size perception is malleable and can be altered using visual adaptation paradigms. However, it is unclear whether such visual adaptation effects also transfer to other modalities and influence, for example, the perception of tactile distances. In this study we employed a visual adaptation paradigm. Participants were exposed to images of expanded or contracted versions of self- or other-identity bodies. Before and after this adaptation they were asked to manipulate the width of body images to appear as “normal” as possible. We replicated an effect of visual adaptation, such that the body size selected as most “normal” was larger after exposure to expanded and thinner after exposure to contracted adaptation stimuli. In contrast, we did not find evidence that this adaptation effect transfers to distance estimates for paired tactile stimuli delivered to the abdomen. A Bayesian analysis showed that our data provide moderate evidence that there is no effect of visual body size adaptation on the estimation of spatial parameters in a tactile task. This suggests that visual body size adaptation effects do not transfer to somatosensory body size representations.