The influence of inversion on the judgment of facial and non-facial attributes

Abstract

We investigated how inversion affects the interstimulus differences of faces and non-faces, as defined in terms of stimulus attributes. Ten faces were presented, both upright and upside-down, to 85 subjects. The subjects were asked to rate the faces according to their perceived trustworthiness (Experiment 1) and perceived age (Experiment 2). To 42 of the subjects we also presented ten cars, again upright and upside-down, and asked them to rate the cars according to their perceived elegance (Experiment 3). For each stimulus class and each attribute, we compared the subjects' ratings across orientations. Inversion decreased the differences between the faces' scores and, although to a much lesser extent, also decreased the differences between the cars' scores. For both stimulus classes, we found this effect of inversion to be regular, as reflected in an approximately linear relationship between the two orientations' scores. These results are discussed with respect to current theories of face perception, which claim that different information is processed in upright and inverted faces.