Physical self-motion facilitates object recognition, but does not enable view-independence

Abstract

It is well known that people have difficulties in recognizing an object from novel views as compared to learned views, resulting in increased response times and/or errors. This so-called view-dependency has been confirmed by many studies. In the natural environment, however, there are two ways of changing views of an object: one is to rotate an object in front of a stationary observer (object-movement), the other is for the observer to move around a stationary object (observer-movement). Note that almost all previous studies are based on the former procedure. Simons et al. [2002] criticized previous studies in this regard and examined the difference between object- and observer-movement directly. As a result, Simons et al. [2002] reported the elimination of this view-dependency when novel views resulted from observer-movement, instead of object-movement. They suggest the contribution of extra-retinal (vestibular and proprioceptive) information to object recognition. Recently, however, Zhao et al. [2007] reported that the observer's movement from one view to another only decreased view-dependency without fully eliminating it. Furthermore, even this effect vanished for rotations of 90° instead of 50°. Larger rotations were not tested. The aim of the present study was to clarify the underlying mechanism of this phenomenon and to investigate larger angles of view change (45-180°, in 45° steps).