Abstract
An important aspect of face recognition involves the role of featural and configurational information for face perception (e.g. Tanaka & Farah, 1993; Yovel & Duchaine, 2006; Rotshtein et al., 2007).
In our study, we investigated the influence of featural and configural information on perceived similarity between faces. Eight pairs of male faces were chosen from our digital face database (http://faces.kyb.tuebingen.mpg.de). The texture and the face shape for both faces in a pair were equalized to create 2 basis faces that differed only in their inner facial features and their configuration, but not in face shape or texture. A computer algorithm allowed to parametrically morph the features, the configuration, or both between the two basis faces of a pair. In our case the morphing was done in 25% steps.
24 participants rated the similarity between pairs of the created faces using a 7-point Likert scale. The faces to compare came from the same basis face pair and could differ either in features or in configuration by 0%, 25%, 50%, 75% or 100%.
The results revealed that for the same amount of morphing, faces differing by their features are perceived as less similar than faces differing by their configurations. These findings replicate previous results obtained with less natural or less controlled conditions. Furthermore, we found that linear increases of the difference between both faces in configural or featural information resulted in a nonlinear increase of perceived dissimilarity. An important aspect for the relevance of our results is how natural the face stimuli look like. We asked 24 participants to rate the naturalness of all stimuli including the original faces and the created faces. Despite numerous manipulations, the vast majority of our created face stimuli were rated as natural as the original faces.