Shifts in Postdiscrimination Gradients within a Stimulus Dimension Based on Bilateral Facial Symmetry

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Bibliographic Details
Title: Shifts in Postdiscrimination Gradients within a Stimulus Dimension Based on Bilateral Facial Symmetry
Language: English
Authors: Derenne, Adam
Source: Journal of the Experimental Analysis of Behavior. May 2010 93(3):485-494.
Availability: Society for the Experimental Analysis of Behavior. Available from: Indiana University Department of Psychology. Bloomington, IN 47405-1301. Tel: 812-334-0395; FAX: 812-855-4691; e-mail: jeab@indiana.edu; Web site: http://seab.envmed.rochester.edu/jeab/index.html
Peer Reviewed: Y
Physical Description: PDF
Page Count: 10
Publication Date: 2010
Document Type: Journal Articles
Reports - Research
Education Level: Higher Education
Postsecondary Education
Descriptors: Stimulus Generalization, Discrimination Learning, Shift Studies, Visual Stimuli, Human Body, Geometry, Undergraduate Students, Comparative Analysis
ISSN: 0022-5002
Abstract: A shift in generalization gradients away from S+ and towards stimuli on the opposite end of the stimulus dimension from S- is a well established phenomenon in the laboratory, occurring with humans and nonhumans and with a wide range of stimuli. The phenomenon of gradient shifts has also been observed to have an analogous relationship to a variety of apparent biases in preference observed in the natural environment. One way to examine the validity of such analogies is by examining whether gradient shifts can be observed with complex and naturalistic stimuli. In the present experiment, undergraduates were trained to discriminate between faces that varied in terms of relative bilateral facial symmetry (a stimulus dimension correlated with health and attractiveness). Comparisons were made within subjects, using two sets of images. For both sets, the faces varied from naturally asymmetrical to symmetrical, and S+ was a face equidistant to the two extremes. With one set, S- was the naturally asymmetrical face, and with the other, S- was the symmetrical face. A peak shift was obtained in both conditions, although the effect was clearer in the aggregate than on the level of the individual. Overall, the results are consistent with the view that the processes responsible for gradient shifts in the lab are relevant to judgments made in the natural environment. (Contains 5 figures and 1 table.)
Abstractor: As Provided
Number of References: 51
Entry Date: 2010
Access URL: https://seab.envmed.rochester.edu/jeab/toc/2010/jeabmay10.php
Accession Number: EJ886968
Database: ERIC
Description
Abstract:A shift in generalization gradients away from S+ and towards stimuli on the opposite end of the stimulus dimension from S- is a well established phenomenon in the laboratory, occurring with humans and nonhumans and with a wide range of stimuli. The phenomenon of gradient shifts has also been observed to have an analogous relationship to a variety of apparent biases in preference observed in the natural environment. One way to examine the validity of such analogies is by examining whether gradient shifts can be observed with complex and naturalistic stimuli. In the present experiment, undergraduates were trained to discriminate between faces that varied in terms of relative bilateral facial symmetry (a stimulus dimension correlated with health and attractiveness). Comparisons were made within subjects, using two sets of images. For both sets, the faces varied from naturally asymmetrical to symmetrical, and S+ was a face equidistant to the two extremes. With one set, S- was the naturally asymmetrical face, and with the other, S- was the symmetrical face. A peak shift was obtained in both conditions, although the effect was clearer in the aggregate than on the level of the individual. Overall, the results are consistent with the view that the processes responsible for gradient shifts in the lab are relevant to judgments made in the natural environment. (Contains 5 figures and 1 table.)
ISSN:0022-5002