Document Type Master's Dissertation Author Radaelli, Stephano firstname.lastname@example.org URN etd-11132008-153318 Document Title The role of perceptual learning in accounting for the own-race bias, the inversion effect, and the distinctiveness effect in recognition memory for faces from a developmental perspective Degree Master of Arts Department Psychology Supervisor
Advisor Name Title Prof P Chiroro Supervisor Keywords
- face perception
Date 2008-09-05 Availability restricted Abstract
The rated distinctiveness of a face, the orientation in which a face is seen and the race of the face, are all factors that are known to affect subsequent recognition of faces. These three factors are known as the distinctiveness effect, the orientation effect and the own-race bias. The main objective of this study was to track the extent to which these three effects develop across the lifespan. The study consisted of three experiments. The first experiment was designed to gather distinctiveness ratings for a large set of black and white faces and to establish whether there was a significant correlation between the distinctiveness ratings provided by black and white participants on both black and white faces. The correlation coefficient between ratings of white faces from both the black and white subjects was significant r(23) = 0.64 (p<0.01). From the ratings obtained during this experiment, equal numbers of distinctive and typical faces of each race were selected for use in experiment 2. The second experiment was designed to determine whether the distinctiveness effect, the inversion effect and the cross-race effect would emerge using stimuli selected as part of experiment 1. The results showed significant main effects of distinctiveness (F(1, 46) = 13.623, p<0.05) and of face orientation (F(1, 46) = 75.204, p<0.05). Furthermore, there was a significant interaction between race of face and race of subject (F(1,46)= 18.744, p<0.05). The third experiment sought to determine the progression of the distinctiveness effect, the inversion effect and the cross-race effect from early childhood (i.e. 6 years) to early adulthood (i.e. 23 years), using both recognition accuracy and response latency as dependent variables. As predicted, the results showed a significant main effect of face distinctiveness (F(6, 154) = 40.229, p<0.05), orientation of the face (F(6, 154) = 175.132), age of subjects (F(6, 154) = 28.892, p<0.05) However, these effects were accompanied by unpredicted main effects of race of face (F(6, 154) = 24.184, p<0.05) and race of subjects (F(1, 154) = 8.957, p<0.05). Also, the following interactions were significant: distinctiveness X orientation X race of face X race of subject and age of subject (F(6, 154) = 3.461, p<0.05); race of face and race of subject (F(6, 154) = 2.081, p<0.05); race of face X race of subject X age of subject (F(13,154) = 2.246, p<0.05); age of subject X orientation of the face (F(6, 154) = 2.886, p<0.05); age of subject X race of face X orientation of the face (F(6, 154) = 2.284, p<0.05).
Overall, the distinctiveness effect, inversion effect and own-race bias was evident among participants who were older than 8 years. Six-year-olds did not show a bias towards recognising distinctive, upright or own-race faces. Also, the own-race bias continued to affect the white subjectís ability to recognise faces as they became older but this was not the case for black subjects.
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