Research has shown that the haptic perception of orientation is susceptible to systematic spatial bias. Large and systematic deviations have been found in haptic parallelity matching tasks supporting a reference frame based model. It has been suggested that the observed deviations result from the use of a frame of reference that is intermediate to an allocentric and an egocentric reference frame. The systemic bias of the deviations seems be caused by the strong bias produced by the hand-centered egocentric reference frame. In this paper results of studies are discussed showing a strong evidence for the abovementioned model in which egocentric representations exist in parallel to allocentric ones, and in which the former is biased by a hand-centered reference frame. The extent to which each representation is used appears to depend on factors like orientation, distance, gender, task instruction, practice and training. Manipulations stimulating allocentric processing or reducing egocentric processing have been shown to affect haptic parallelity performance.
展开▼
