Dominance of texture over shape in facial identity processing is modulated by individual abilities

Abstract

For face recognition, observers utilize both shape and texture information. Here, we investigated the relative diagnosticity of shape and texture for delayed matching of familiar and unfamiliar faces (Experiment 1) and identifying familiar and newly learned faces (Experiment 2). Within each familiarity condition, pairs of 3D-captured faces were morphed selectively in either shape or texture in 20% steps, holding the respective other dimension constant. We also assessed participants' individual face-processing skills via the Bielefelder Famous Faces Test (BFFT), the Glasgow Face Matching Test, and the Cambridge Face Memory Test (CFMT). Using multilevel model analyses, we examined probabilities of same versus different responses (Experiment 1) and of original identity versus other/unknown identity responses (Experiment 2). Overall, texture was more diagnostic than shape for both delayed matching and identification, particularly so for familiar faces. On top of these overall effects, above-average BFFT performance was associated with enhanced utilization of texture in both experiments. Furthermore, above-average CFMT performance coincided with slightly reduced texture dominance in the delayed matching task (Experiment 1) and stronger sensitivity to morph-based changes overall, that is irrespective of morph type, in the face identification task (Experiment 2). Our findings (1) show the disproportionate importance of texture information for processing familiar face identity and (2) provide further evidence that familiar and unfamiliar face identity perception are mediated by different underlying processes.

Understanding human individuation of unfamiliar faces with oddball fast periodic visual stimulation and electroencephalography

“…Face shape is essentially defined by the bone structure and soft tissue of the face, while surface cues reflect variations in color and texture (such as redness, stubble, and wrinkles; Bruce & Young, 1998). Results showed a large response over right occipito‐temporal electrodes for FI based on in shape cues, but a more bilateral and larger response for FI based on surface cues, as supported by subsequent behavioral evidence (Itz, Golle, Luttmann, Schweinberger, & Kaufmann, 2017). Critically, the sum of the FI response amplitude to shape and surface changes alone was lower than when both cues varied simultaneously, revealing a supra‐additive effect not disclosed by behavioral studies (Itz et al., 2017; O'Toole et al, 1999; Russell, Biederman, Nederhouser, & Sinha, 2007).…”

Contributions of feature shapes and surface cues to the recognition and neural representation of facial identity

“…This allows observers to discern invariant features of the face that are common across previous images. Our findings suggest that the surface properties that we have defined play a key role in the invariant representation that leads to the recognition of familiar faces (see also, Itz et al, 2014;2016b). The reason shape information may not be such a reliable cue for the recognition of identity is that it is less stable across images (Burton, 2013).…”

Temporal Contiguity Training Influences Behavioral and Neural Measures of Viewpoint Tolerance

“…Even though natural photos of faces are no doubt the most representative of the faces we encounter in our everyday lives, we used computer-rendered face images to have better stimulus control while still retaining a lot of the properties of naturalistic faces (e.g., skin texture). Studies have indicated that both shape and texture/surface information are important for face recognition ( O’Toole et al, 1999 ; Jiang F. et al, 2006 ; Caharel et al, 2009 ; Itz et al, 2017 ) and both types of information have been suggested to contribute to the holistic processing of faces ( Meinhardt-Injac et al, 2013 ; Zhao et al, 2016 ). Likely, the performance with our stimulus set is also influenced by shape as well as texture.…”