Facial age after-effects show partial identity invariance and transfer from hands to faces

Age imparts long-term dynamic changes to faces: how these are represented in the human visual system has seldom been investigated. We investigated facial age after-effects using a perceptual bias paradigm, and studied the ability of adaptation to transfer across face identity, visual stimuli and sensory modality, as has been done for the short-term dynamic changes of facial expression. Age after-effects were reduced but still significant when the identity of the face was changed between the adapting and test stimuli, as we had found for expression after-effects, suggesting identity-specific and identity-invariant components of age after-effects. Although body silhouettes and greyscale body images failed to generate age after-effects in faces, we did find cross-stimulus transfer of age adaptation from hands to faces. There was no cross-modal transfer of after-effects from voices to faces. These findings confirm that face adaptation has components that cannot be explained by low-level image-based effects but involve high-level representations that may be influenced by related visual semantic information.