The effects of expertise, such as better recognition of own-race than other-race faces, have been attributed either to poor encoding of configural information (the dual-mode theory) or to representation of faces on dimensions attuned to own-race faces and, hence, inappropriate for coding of other-race faces (the ABC model). Neither framework alone has been able to account for the variety of past results. It is proposed that a composite account derived from the dual-mode theory and the ABC model may offer a more complete explanation of the effects of race. To evaluate the composite account, six experiments using perceptual paradigms were carried out.
The structure of face space and the effects of expertise on configural processing were assessed in a dissimilarity perception task (Experiment 1). Caucasian and Chinese participants judged dissimilarity of own-race and other-race faces with various configural distortions relative to their unaltered versions. As predicted by the composite account, face spaces derived from the dissimilarity ratings for own-race and other-race faces were comparable. Consistent with the premise that expertise affects configural coding, Caucasian participants exhibited greater sensitivity to configural changes of own-race than other-race faces.
The effects of expertise on configural encoding were further examined in a bizarreness perception paradigm (Experiments 2-4). Caucasian participants rated bizarreness of unaltered and distorted faces rotated from upright to inverted in 15� increments. The distortions involved either simple component alterations (i.e., whitened pupils and blackened teeth), global configural changes (i.e., inverted eyes and mouth), or more local configural transformations (e.g., moving the eyes closer together and upwards, and shifting the mouth down). Similar bizarreness ratings for all faces with component distortions confirmed that expertise does not affect processing of simple component information. Differences in the perceived bizarreness of own-race and other-race faces in the unaltered and global configural distortion conditions corroborated the hypothesis that expertise influences holistic configural encoding. Variations in the perceived bizarreness of faces with more local configural changes, however, indicated that expertise might also affect local configural coding.
The effects of expertise on local configural processing were further examined in a discrimination paradigm (Experiments 5 and 6). Participants made same-different decisions with upright and inverted face pairs comprising either two identical faces (same trials) or unaltered and distorted versions of the same face (different trials). To distinguish between holistic and local processing of configural information, partial faces were created in addition to whole faces. Higher accuracy for own-race than other-race faces at both upright and inverted orientations in both whole and partial face conditions substantiated the argument that expertise modulates local configural encoding.
Altogether, the present investigation offers direct evidence for the composite account of the effects of race. As ventured by the composite account, the own-race face bias in face perception was shown to be due to variations in configural processing. In addition, the reported experiments support the argument that configural information can be encoded both locally and holistically.
| Identifer | oai:union.ndltd.org:ADTP/217509 |
| Date | January 2006 |
| Creators | Schuchinsky, Maria, n/a |
| Publisher | University of Otago. Department of Psychology |
| Source Sets | Australiasian Digital Theses Program |
| Language | English |
| Detected Language | English |
| Rights | http://policy01.otago.ac.nz/policies/FMPro?-db=policies.fm&-format=viewpolicy.html&-lay=viewpolicy&-sortfield=Title&Type=Academic&-recid=33025&-find), Copyright Maria Schuchinsky |
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