Age decisions on familiar and unfamiliar faces

The extraction of age is among the "early visual processes" that operate on faces. Current cognitive models mention this operation, but data on the subject is rare. In the first experiment, a series of familiar and unfamiliar faces were displayed to subjects who were asked to make old/young categorizations. To test how early this operation occurs, the same material was used for familiarity decision. Finally, the stimuli were displayed centrally to 16 subjects and laterally to 32 subjects. The age decision was easier and quicker than the familiarity decision; the familiarity decision was unaffected by the age of the faces, while face familiarity affected the extraction of age. In a second experiment (40 subjects), we manipulated the ambiguity of the apparent age and conditional tasks were used, i.e., the subjects had to process both age and familiarity in a single task. The results suggest that age extraction is an operation that is mandatory for an efficient recognition process. Therefore, it is proposed to dissociate, within the semantic visually derived codes, the processing of age from the processing of sex and race.