Role of features and second-order spatial relations in face discrimination, face recognition, and individual face skills: Behavioral and functional magnetic resonance imaging data

& We compared the contribution of featural information and second-order spatial relations (spacing between features) in face processing. A fully factorial design has the same or differ-ent ‘‘features’ ’ (eyes, mouth, and nose) across two successive displays, whereas, orthogonally, the second-order spatial re-lations between those features were the same or different. The range of such changes matched the possibilities within the population of natural face images. Behaviorally, we found that judging whether two successive faces depicted the same per-son was dominated by features, although second-order spatial relations also contributed. This influence of spatial relations correlated, for individual subjects, with their skill at recognition of faces (as famous, or as previously exposed) in separate be-havioral tests. Using the same repetition design in functional magnetic resonance imaging, we found feature-dependent ef-fects in the lateral occipital and right fusiform regions. In addition, there were spatial relation effects in the bilateral in-ferior occipital gyrus and right fusiform that correlated with individual differences in (separately measured) behavioral sen-sitivity to those changes. The results suggest that featural and second-order spatial relation aspects of faces make distinct con-tributions to behavioral discrimination and recognition, with features contributing most to face discrimination and second-order spatial relational aspects correlating best with recogni-tion skills. Distinct neural responses to these aspects were found with functional magnetic resonance imaging, particularly when individual skills were taken into account for the impact of second-order spatial relations. &amp