知觉适应对种族融合面孔的种族分类和知觉辨别的影响

面孔加工的种族效应(the other-race effects)指人们对面孔做个体辨别任务时辨别本族面孔的绩效优于辨别他族面孔的绩效, 而做种族分类任务时分类他族面孔的绩效优于分类本族面孔的绩效。本研究通过知觉适应操纵被试对种族两歧(高加索和亚洲)融合面孔的种族知觉, 进而比较被试在两种条件下对同一张融合面孔进行种族分类和知觉辨别的绩效的差异。结果发现, 知觉适应能使被试产生将两歧融合面孔知觉为与原始面孔所属种族相反种族的知觉偏向, 并且, 伴随着这种知觉偏向, 两歧融合面孔的加工出现了他族分类优势和本族辨别优势, 提示社会认知因素对面孔加工的种族效应有重要作用。

Race Categorization and Perceptual Discrimination of Morphing Faces Are Modulated by Perceptual Adaptation

The other-race effect (ORE) refers to the own-race discrimination advantage and the other-race categorization advantage. The perceptual expertise theory explains the ORE as a result of people’s long-term perceptual exposure to own-race faces much more than the other-race faces. However, recent findings suggest that short- term, social-cognitive factors, such as reduced motivation to individuate other-race faces, may also contribute to the ORE. To examine the effect of short-term factor on face perceptual processing, we manipulated perceptual adaptation in three experiments and investigated participants’ face race perception and discrimination. In Experiment 1, 20 Asian participants were presented with 704 color Asian-Caucasian morphed face stimuli for a race categorization task. These stimuli were generated with morphing software (MorphTM), allowing the creation of 11 blended face stimuli (from 0:100 to 100:0 for Asian:Caucasian proportions, respectively) for each of 64 Asian-Caucasian continua. In each continuum, the face that was equally often categorized as Asian and as Caucasian was identified as the ambiguous-race face. Result showed that the 52 Asian-Caucasian ambiguous faces were extracted and used as face stimuli in experiment 2 and experiment 3. In Experiment 2, we examined the effects of perceptual adaptation on face race categorization performance by presenting the ambiguous-race faces after prolonged exposure (5 seconds) to a Caucasian or an Asian face. Results showed that prolonged exposure to Asian faces causes the identical ambiguous-race morphed faces to appear distinctly Caucasian, vice versa. Furthermore, the identical ambiguous-race morphed faces were categorized faster when the faces were perceived as Caucasian but slower when the faces were perceived as Asian. In experiment 3, we examined the effects of perceptual adaptation on face discrimination by presenting the ambiguous-race faces after prolonged exposure (5 seconds) to a Caucasian or an Asian face. Results showed that the identical ambiguous-race morphed faces were discriminated more accurate when the faces were perceived as Asian but less accurate when the faces were perceived as Caucasian. Collectively, these findings indicate that the short-term, perceptual adaptation may affect participants’ face race categorization and perceptual discrimination, suggesting social-cognitive factors also play a role in the ORE.