What is "special" about face perception?

There is growing evidence that face recognition is "special" but less certainty concerning the way in which it is special.The authors review and compare previous proposals and their own more recent hypothesis, that faces are recognized "holisticaily" (i.e., using relatively less part decomposition than other types of objects).This hypothesis, which can account for a variety of data from experiments on face memory, was tested with 4 new experiments on face perception.A selective attention paradigm and a masking paradigm were used to compare the perception of faces with the perception of inverted faces, words, and houses.Evidence was found of relatively less part-based shape representation for faces.The literatures on machine vision and single unit recording in monkey temporal cortex are also reviewed for converging evidence on face representation.The neuropsychological literature is reviewed for evidence on the question of whether face representation differs in degree or kind from the representation of other types of objects.Several lines of research have suggested that face recognition is "special."Neuropsychological studies have demonstrated that face recognition can be selectively impaired relative to the recognition of objects of equivalent difficulty, implying that people use different brain areas for face recognition and other types of object recognition (Farah, Klein, & Levinson, 1995).Single unit recordings in monkeys have revealed a population of ceils in the temporal cortex that respond selectively to faces, in some cases responding differentially to particular faces, suggesting a role for these cells in face recognition (e.g., see Desimone, 1991, for a recent review).Although cells have also been found that respond to nonface objects, the selectivity and strength of such responses are weaker (Baylis, Rolls, & Leonard, 1985).Developmentally, face recognition appears to have an innate component.At just 30 min of age, infants will track a moving face farther than other moving patterns of comparable contrast, complexity, and spatial frequency (Johnson, Dziurawiec, Ellis, & Morton, 1991).The face inversion effect, discussed in more detail later, provides another indication that face recognition is different from other kinds of object recognition.Whereas most objects are somewhat harder to recognize upside down