Abstract # 93:

Scheduled for Friday, June 18, 2010 07:00 PM-09:00 PM: Session 18 (Medallion Ballroom C/D/E/F) Poster Presentation


COMMUNICATIVE BEHAVIORS OF CAPUCHIN MONKEYS (CEBUS APELLA) VARY WITH ATTENTIONAL STATE OF AN OBSERVER AND DESIRABILITY OF FOOD

K. A. Phillips1,2, V. R. Gilbert3 and S. Morales3
1Trinity University, Department of Psychology, San Antonio, TX 78212, USA, 2Southwest National Primate Research Center, 3Hiram College
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We investigated whether capuchins would alter their communication modality in response to two varying conditions: attentional state of a human observer and desirability of an out-of-reach food reward. We hypothesized that capuchins would engage in more gaze alternation when the observer was facing the subject and more vocalizations when the observer was facing away. Food desirability was predicted to mediate the effect of observer attentional state. Nine capuchins were tested in an experimental paradigm where the quality of the food (highly desirable or less desirable) and the attentional state of the observer (facing either toward or away from the subject) were manipulated. Each subject received four trials of each type in a counterbalanced order. Subjects performed more gaze alternation when the observer was facing the subject and there was a highly desirable food [ANOVA: α=0.05]. Gaze alternation did not vary as a function of food desirability in the facing away conditions. Subjects did not perform more vocalizations when the observer was facing away [ANOVA: α=0.05], nor did vocalization frequency vary as a function of food quality. Latency of communicative behavior was shorter in the presence of highly desirable food, regardless of observer attentional state [ANOVA: α=0.05]. Our results indicate that capuchins are sensitive to the attentional state of an observer and may vary the modality of communication accordingly.