Abstract
Adaptation can strongly influence many natural attributes of faces such as their gender, identity or ethnicity. In this study we examined how adaptation affects the perceived age of a face. Stimuli were frontal view images of male and female faces with average features and neutral expressions created with Singular Inversions FaceGen Modeller software. The images were manipulated to simulate aging in a continuum from approximately 20 to 65 years. Participants classified images as young or old using a staircase task to find the boundary between participants' young and old categories. These boundaries were strongly biased by prior exposure to old or young faces. Thus perceived age, like other facial attributes, is highly susceptible to adaptation and may therefore be routinely regulated by the average age characteristics an observer is exposed to. Like many other facial categories, age-related variations include changes in both the shape and the pigmentation and texture of the face, the latter of which have also been found to provide important cues in face recognition (e.g. Russell et al, 2006). In further experiments we compare the form and selectivity of adaptation effects for pigmentation and shape changes in faces to assess whether these dimensions are jointly coded in the mechanisms underlying face adaptation.