Abstract
All faces are created equal in the sense that each face shares the same set of features of two eyes, a nose and a mouth that are arranged in a similar configuration. Given their common parts and spatial layout, recognition of a specific face must therefore depend on our ability to discern subtle differences in the featural and configural properties of a face. An enduring question in the face processing literature is whether featural or configural information plays a larger role in the recognition process. To address this question, the Face Dimensions Test was designed where the featural and configural properties in the upper and lower regions of a face were parametrically manipulated. Configural information was modified by varying either the distance between the eyes or the distance between the nose and mouth. Featural information was manipulated by either scaling the size of the eyes or mouth features (Experiment 1) or altering their shapes via a morphing procedure (Experiment 2).
In a same/different task, discriminability was first equated across the four dimensions (eyes-featural, eyes-configural, mouth-featural and mouth-configural) in faces shown in their upright orientations. Next, sensitivity was measured when the faces were presented upside down. Whereas inversion equally impaired the discrimination of featural and configural differences, it selectively disrupted the perception of changes in the lower region of the face. The lower half deficit appears to be face-specific because changes in orientation did not influence perception of information in top or bottom halves of houses (Experiment 3). In summary, these results suggest that inversion does not differentially interfere with the perception of features and their relations, but produces a general impairment of information in the lower region of a face.
National Sciences and Engineering Research Council of Canada, the James S. McDonnell Foundation, the Temporal Dynamics of Learning Center (NSF Grant #SBE-0542013).