EXPRESS: Spatial representations of objects used away and toward the body: the effect of near and far space.

An action with an object can be accomplished only if we encode the position of the object with respect to our body (i.e. egocentrically) and/or to another element in the environment (i.e. allocentrically). However, some actions with the objects are directed towards our body, such as brushing our teeth, and others away from the body, such as writing. Objects can be near the body, that is within arm reaching, or far from the body, that is outside arm reaching. The aim of this study was to verify if the direction of use of the objects influences the way we represent their position in both near and far space. Objects typically used towards (TB) or away from the body (AB) were presented in near or far space and participants had to judge whether an object was closer to them (i.e. egocentric judgment) or closer to another object (i.e. allocentric judgment). Results showed that egocentric judgments on TB objects were more accurate in near than in far space. Moreover, allocentric judgments on AB objects were less accurate than egocentric judgments in near but not in far space. These results are discussed with respect to the different role that visuomotor and visuospatial mechanisms play in near and in far space, respectively.