IS HUMAN OBJECT RECOGNITION BETTER DESCRIBED BY GEON STRUCTURAL DESCRIPTIONS OR BY MULTIPLE VIEWS - COMMENT ON BIEDERMAN AND GERHARDSTEIN (1993)

Is human object recognition viewpoint dependent or viewpoint invariant under ''everyday'' conditions? I. Biederman and P. C. Gerhardstein (1993) argued that viewpoint-invariant mechanisms are used almost exclusively. However, our analysis indicates that (a) their conditions for immediate viewpoint invariance lack the generality to characterize a :vide range of recognition phenomena, (b) the extensive body of viewpoint-dependent results cannot be dismissed as processing ''by-products'' or ''experimental artifacts,'' and (c) geon structural descriptions cannot coherently account for category recognition, the domain they are intended to explain. The weight of current evidence supports an exemplar-based multiple-views mechanism as an important component of both exemplar-specific and categorical recognition.