A combinatorial study of pose effects in unfamiliar face recognition

The face inversion effect, evidence that humans possess a specialized system for face processing, and the (3/4) view advantage, evidence that a canonical viewpoint exists from which faces may be optimally recognized, are two commonly cited findings in the face processing literature. In this paper, the interaction of these effects is examined in a sequential matching paradigm in which unfamiliar faces are combinatorially randomized in pose across two dimensions (roll and yaw). Using large numbers of poses, trials and face stimuli, two experiments were conducted in which pose was either jointly or independently randomized between intervals. Results include that performance was modulated in a continuous fashion as each dimension was manipulated, that an offset-specific (3/4) advantage exists, that both specific study and test pose affect recognition, and that, for like offset, yaw rotation is more deleterious to performance than roll rotation. Response bias effects included that matched or reflective yaw led observers to employ a more liberal criterion.