Abstract # 184:

Scheduled for Friday, August 18, 2006 07:00 PM-09:00 PM: Session 17 (Regency West 1/3 ) Poster Presentation

Operant Conditioning Fails to Facilitate Mirror Self-Recognition in Capuchin Monkeys (Cebus apella)

M. E. Huntsberry1, A. M. Ruggiero2, C. J. Christensen1, P. G. Roma1, A. Silberberg1 and S. J. Suomi2
1American University, Department of Psychology , Washington, DC, USA, 2Laboratory of Comparative Ethology, NICHD, Poolesville, MD
     A coherent body of research suggests that mirror self-recognition (MSR) is restricted to humans and some great apes. One study by Epstein, Lanza and Skinner (1981) claims to have reproduced this phenomenon in a pigeon. The current study borrows from their methodology attempting to reproduce their results in three adult male capuchin monkeys. Three days before training, a 45x61-cm mirror was installed in the monkeys’ home and test cages where it remained throughout the study. In Phase 1, monkeys were squeezed and their heads sham-marked with gel using a paint brush before entering the test chamber, where an orange mark was placed on a cage surface. Monkeys were shaped to touch the mark (repositioned between sessions). Following training, monkeys’ foreheads were marked with orange paint in a manner identical to the sham-mark, mirror absent. Head touches before and after mirror introduction were recorded, but no mirror-guided mark-touching was observed. In Phase 2, subjects were shaped to touch randomly placed, visible body marks. Following training, testing identical to Phase 1 occurred. Upon mirror introduction, one monkey looked at the mirror and touched his head, whereas others did not. A follow-up test involving marking the upper chest was conducted; however, no monkeys displayed MSR. These results show capuchins fail in MSR despite training in elements of the Epstein et al. procedure except mirror-directed mark touching, suggesting the capacity for perspective-taking seen in humans and some great apes may not be reproducible in capuchins.