Formal models of familiarity and memorability in face recognition

The similarity structure of faces has long been recognized as an important mediator of face recognition. Distinctive faces have an enduring quality to them, such that they are rarely confused with other faces. At the same time, we often encounter a situation in which a particular face looks familiar, yet the individual may only bear a resemblance to several acquaintances. The veracity of these introspections has been borne out by empirical evidence, which has served to identify the information used during face recognition. Much of the research has focused on the role of typicality, which may be defined in various ways, but is often operationalized as a subjective rating of the difficulty of picking a particular face out of a crowd. Defined as such, typicality embodies the similarity structure of faces, such that typical faces will be similar to lots of other faces, while atypical faces will be very dissimilar and appear distinctive as a result.