These studies suggest categorical perception effects may be much more
general than has commonly been believed and can occur in apparently si
milar ways at dramatically different levels of processing. To test the
nature of individual face representations, a linear continuum of ''mo
rphed'' faces was generated between individual exemplars of familiar f
aces. In separate categorization, discrimination and ''better-likeness
'' tasks, subjects viewed pairs of faces from these continua. Subjects
discriminate most accurately when face-pairs straddle apparent catego
ry boundaries; thus individual faces are perceived categorically. A hi
gh correlation is found between the familiarity of a face-pair and the
magnitude of the categorization effect. Categorical perception theref
ore is not limited to low-level perceptual continua, but can occur at
higher levels and may be acquired through experience as well.