title: Not just the norm: exemplar-based models also predict face aftereffects.
abstract: The face recognition literature has considered two competing accounts of how faces are represented within the visual system: Exemplar-based models assume that faces are represented via their similarity to exemplars of previously experienced faces, while norm-based models assume that faces are represented with respect to their deviation from an average face, or norm. Face identity aftereffects have been taken as compelling evidence in favor of a norm-based account over an exemplar-based account. After a relatively brief period of adaptation to an adaptor face, the perceived identity of a test face is shifted toward a face with attributes opposite to those of the adaptor, suggesting an explicit psychological representation of the norm. Surprisingly, despite near universal recognition that face identity aftereffects imply norm-based coding, there have been no published attempts to simulate the predictions of norm- and exemplar-based models in face adaptation paradigms. Here, we implemented and tested variations of norm and exemplar models. Contrary to common claims, our simulations revealed that both an exemplar-based model and a version of a two-pool norm-based model, but not a traditional norm-based model, predict face identity aftereffects following face adaptation.
authors.affiliation: Department of Psychology, Vanderbilt University, 111 21st Avenue South, 301 Wilson Hall, Nashville, TN, 37240, USA, david.ross@vanderbilt.edu.
authors.forename: David A
authors.initials: DA
authors.lastname: Ross
authors.forename: Mickael
authors.initials: M
authors.lastname: Deroche
authors.forename: Thomas J
authors.initials: TJ
authors.lastname: Palmeri
mesh_terms: D003210:Concept Formation; D005145:Face; D006801:Humans; D008960:Models, Psychological; D010364:Pattern Recognition, Visual; D021641:Recognition, Psychology