Datensatz

Zusammenfassung

Prototype referenced adaptation effects were found among face stimuli in a computationally derived multidimensional face space based on a 3D morphing algorithm. Individual faces can be described as points or vectors in this space. An “identity trajectory” connecting a face to the average of all faces, defines a gradient of face individuality. Anti-caricatures lie along the “identity” trajectory between an individual face and the average face. “Anti-faces” lie along this trajectory, but on the “other side of the mean”. While anti-caricatures look like less distinctive versions of the original face, anti-faces have the appearance of an entirely different individual. For example, faces with light complexions and light eyes yield anti-faces with dark complexions and dark eyes, and faces with roundish shapes yield anti-faces with a gaunt, skinny appearance. We found that pre-exposure to an “anti-face”, specifically facilitated the identification of briefly presented anti-caricatures along the same trajectory, while diminishing performance for other non-colinear faces. The perceptual bias following anti-face adaptation was strong enough to cause systematic mislabeling of the average face as the face complement to the pre-exposed anti-face. Additional experiments showed that the adaptation effect survived a range of translations in size and retinal location between pre-exposure and test. Combined, the results suggest that the subordinate perception and recognition of faces, and perhaps other objects, may draw upon contrastive neural mechanisms that reference the central tendency of the stimulus category.