Behavioral research indicates that successful face individuation is associated with sensitivity to subtle spatial relations between facial features, as well as to the features themselves. We used a blocked functional magnetic resonance adaptation paradigm to examine the sensitivity of the core face network to spatial relations in faces. The fusiform face area (FFA) was sensitive to spatial relations, responding more strongly to a single face presented with various feature spacings than to repeated presentations of an identical face. This response to spacing variations was as strong as the response to a series of distinct identities. There were no hemisphere effects in sensitivity to spatial relations, although FFAs were larger on the right. The right occipital face area (OFA) was also sensitive to spatial relations in faces. Few participants showed left OFAs. The superior temporal sulcus (STS), which does not code identity, showed little sensitivity to either relational changes or changes in identity. We suggest that the sensitivity of the FFA and right OFA to spatial relations in faces may contribute to our impressive ability to individuate faces despite their similarity as visual patterns.
European Journal of Neuroscience Vol. 30, Issue 4, p. 721-733