Face recognition stands out as a singular case of object recognition: Although most faces are very much alike, people discriminate between many different faces with outstanding efficiency. Even though little is known about the mechanisms of face recognition, viewpoint dependence — a recurrent characteristic of research in face recognition — could help to understand algorithmic and representational issues. The current research tests whether learning only one view of a face could be sufficient to generalize recognition to other views of the same face. Computational and psychophysical research (Poggio & Vetter, 1992) showed that learning one view of a bilaterally symmetric object could be sufficient for its recognition, if this view allows the computation of a symmetric, "virtual," view. Faces are roughly bilaterally symmetric objects. Learning a side-view — which always has a symmetric view — should allow for better generalization performances than learning the frontal view. Two psychophysical experiments tested these predictions. Stimuli were views of shaded 3D models of laserscanned faces. The first experiment tested whether a particular view of a face was canonical. The second experiment tested which single views of a face give rise to best generalization performances. The results were compatible with the theoretical predictions of Poggio and Vetter (1992): learning a side view allows better generalization performances than learning the frontal view.

The representation of navigable space, consisting of multiple interconnected spaces, yet is not well understood. Weexamined different levels of integration within memory (local, regional, global). Participants learned two distinctive regions ofa virtual environment that converged at a common transition-point. Subsequently, we tested their memory with a pointing task,varying body alignment during pointing, corridor distance to and regional belonging of the target. Pointing latency increasedwith increasing distance to the target and when pointing into the other region. Further, alignment with local, regional and globalreference frames were found to facilitate pointing latency. These findings suggest that participants memorized local corridors,clustered corridors into regions, and also formed global reference frames, thus, represented the environment on multiple levelsof integration. They are inconsistent with conceptions of spatial memory for navigable environments based either on exclusiverepresentation within a single reference frame or exclusive reliance on local reference frames.