Abstract # 33:

Scheduled for Thursday, June 20, 2013 11:30 AM-11:45 AM: Session 4 (San Geronimo Ballroom C) Oral Presentation


L. M. Mahovetz1,2 and T. S. Stoinski2,3
1Georgia State University, Dept. of Psychology, P.O. Box 5010, Atlanta, GA 30302, USA, 2Zoo Atlanta, 800 Cherokee Avenue, Atlanta, GA 30315, USA, 3The Dian Fossey Gorilla Fund International, 800 Cherokee Avenue, Atlanta, GA 30315, USA

Aging in humans and Old World monkeys is commonly associated with decrements in motor function including dexterity, speed, and strength. Despite their longevity and phylogenetic relatedness to humans, the effects of aging on motor function in non-human apes have not been studied. We conducted an experiment with 12 western lowland gorillas ranging from 10 to 54 years of age to determine whether aged gorillas exhibit motor deficits similar to those seen in humans and monkeys. In the experiment, gorillas were given the opportunity to extract twelve food rewards that were lodged in holes of a Lexan board. Extraction rates (number of rewards per minute) were calculated for eight test sessions. An 8x2 repeated measures ANOVA with sex as a covariate revealed no main effects of session or sex on extraction rate, but a significant main effect of age (F(1,9) = 19.720, p = .002) and a significant interaction between age and session (F(7,63) = 2.29, p = .038). A post-hoc paired samples t-test comparing the first and last sessions showed that experience significantly improved extraction rates in young but not aged gorillas (young: t(6) = -2.976, p = .025, aged: t(4) = 1.237, p = .284). These results suggest that aged gorillas experience deficits in bimanual coordination compared to younger gorillas. The implications for understanding age related deficits in humans and animals will be discussed.