Vision shapes tactile spatial perspective taking
Résumé
Information from the environment can be perceived according to egocentred or decentred spatial perspectives. Different spatial perspectives can be adopted when perceiving not only visual, but also auditory or tactile information. As 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 three perspectives can be adopted (trunk-centred, head-centred and decentred). 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 permanent lack of vision promotes spontaneous adoption of egocentred spatial coordinates, anchored to the head. Moreover, more decentred coordinates were adopted by the blindfolded-sighted compared to the early and late-blind, suggesting that blindness reduces the adoption of decentred perspectives. Finally, the early-blind exhibited a greater cost of switching perspectives compared to 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.
Origine : Fichiers produits par l'(les) auteur(s)