Vision shapes tactile spatial perspective taking.

Abstract

Information from the environment can be perceived according to ego-centered or decentered spatial perspectives. Different spatial perspectives can be adopted when perceiving not only visual but also auditory or tactile information. Because vision may be dominant in setting up spatial information processing, visual loss might affect perspective taking in other sensory modalities. The present study investigated the influence of vision on the perspective that is adopted naturally and the influence of visual experience on the ability to switch between perspectives in the tactile domain. Participants with varying degrees of visual experience (early blind, late blind, blindfolded-sighted, and sighted) completed a tactile recognition task of ambiguous letter stimuli ("b," "d," "p," and "q") presented on the body, for which 3 perspectives can be adopted (trunk centered, head centered, and decentered). The participants were first free to adopt any perspective they wanted before either the same or a different perspective was imposed. The results showed that both a temporary and a permanent lack of vision promote spontaneous adoption of ego-centered spatial coordinates, anchored to the head. Moreover, more decentered coordinates were adopted by the blindfolded-sighted compared with the early and late blind, suggesting that blindness reduces the adoption of decentered perspectives. Finally, the early blind exhibited a greater cost of switching perspectives compared with the sighted, suggesting that early visual experience is important for flexible perspective taking. Overall, our study reveals that vision shapes both the naturally adopted perspective and the flexibility to change perspective. (PsycInfo Database Record (c) 2021 APA, all rights reserved).