Sensitivity to Perspective Structure While Walking without Vision

Abstract

Experiments are reported of the nonvisual sensitivity of observers to their paths of locomotion and to the resulting changes in the structure of their perspectives, ie changes in the network of directions and distances spatially relating them to objects fixed in the surrounding environment. In the first experiment it was found that adults can keep up to date on the changing structure of their perspectives even in the absence of sights and sounds that specify changes in self-to-object relations. They do this rapidly, accurately, and, according to the subjects' reports, automatically, as if perceiving the new perspective structures. The second experiment was designed to investigate the role of visual experience in the development of sensitivity to occluded changes in perspective structure by comparing the judgments of sighted adults with those of late-blinded adults (who had extensive life histories of vision) and those of early-blinded adults (who had little or no history of vision). The three groups performed similarly when asked to judge perspective while imagining a new point of observation. However, locomoting to the new point greatly facilitated the judgments of the sighted and late-blinded subjects, but not those of the early-blinded subjects. The findings indicate that visual experience plays an important role in the development of sensitivity to changes in perspective structure when walking without vision.

Systems of Spatial Reference in Human Memory

“…The role of egocentric reference systems in spatial memory is, at this point, well documented (e.g., Diwadkar & McNamara, 1997;Presson & Montello, 1994;Rieser, 1989;Rieser, Guth, & Hill, 1986; Roskos-Ewoldsen, McNamara, Shelton, & Carr, 1998;Shelton & McNamara, 1997a, 1997b; Sholl & Nolin, 1997). For example, Roskos-Ewoldsen et al (1998) had participants learn four-point paths (see Fig.…”

Motor processes in mental rotation

“…Given that these STP cells distinguish self-produced from external movement, they must have access to a visual representation of the anticipated results of the motor act. In addition, Rieser and his colleagues (Rieser et al, 1986) have shown that when people memorize the positions of several objects and then walk blindfolded to a new location, they can quickly and accurately point to the new egocentric positions of the objects. This 'mental updating' seems to be automatic and difficult to inhibit; after memorizing an object's position and moving without vision, it is easier to give the object's new, mentally-updated position than the old, memorized one.…”

Imagined own-body transformations during passive self-motion

“…For instance, rotating oneself on a desk chair to take the same visual perspective as a colleague results in a stimulation of the semicircular channels and in the spatial updating of our own body position based on visual and vestibular information (Angelaki & Cullen, 2008). Rieser, Guth, & Hill, (1986) have underlined the importance of vestibular information for spatial localization, by showing that blindfolded participants walking a short distance were well able to keep track of their visuo-spatial perspective. Furthermore, recent work has shown the importance of vestibular information for the experienced first person perspective and for bodily selfconsciousness (Ferre, Bottini, & Haggard, 2011;Ionta et al, 2011;Lopez, Bachofner, Mercier, & Blanke, 2009;Lopez, Lenggenhager, & Blanke, 2010).…”