Abstract # 212:

Scheduled for Monday, September 21, 2009 11:30 AM-11:40 AM: Session 22 (Mission Bay Ballroom AB) Oral Presentation


EXPERTISE AND THE INVERSION EFFECT IN CAPUCHIN (CEBUS APELLA) FACE PROCESSING

J. Pokorny, C. Webb and F. B. de Waal
Living Links, Yerkes National Primate Research Center, Atlanta, GA 30322, USA
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The face inversion effect may be defined as the general impairment in recognition that occurs when faces are rotated 180°. This phenomenon seems particularly strong for faces as opposed to other objects, and is often used as a marker of a specialized face processing mechanism. Four brown capuchin monkeys (Cebus apella) were tested on their ability to discriminate several classes of grayscale face and non-face stimuli presented in both their upright and inverted orientations in an oddity task. A hierarchical logistic regression revealed significantly better performance on upright than inverted presentations of capuchin [Wald=27.01, p<0.001] and human (Homo sapien; Wald=11.35, p<0.01] face stimuli, but not on chimpanzee faces [Pan troglodyte; Wald=1.29, p=0.26] or automobiles [Wald = 0.07, p =0.79], suggesting that subjects processed conspecific and human faces in a configural manner. These data support previous studies in humans and other primates suggesting that the inversion effect occurs for stimuli for which subjects have developed an expertise.