Abstract # 53:

Scheduled for Saturday, August 26, 2017 06:00 PM-08:00 PM: (National Ballroom AB) Poster Presentation


G. Vaira1,2 and P. Nealen 1
1Indiana University of Pennsylvania , Indiana , PA 15705, USA, 2Pittsburgh Zoo and PPG Aquarium
     Cognitive testing of zoologically-housed siamangs (Symphalangus syndactylus; Hylobatidae) is being conducted using touch-screen hardware and software (CANTAB, Lafayette Instruments) designed to evaluate a range of cognitive capabilities. Extensive testing has been completed with one subject; other subjects currently are being evaluated. After training on the use of the touch-screen, 418 cognitive trials were completed with the first subject (nulliparous female, age 7) over 8 testing sessions (~50 trials/session). Three cognitive tests were used: Delayed Match-to-Sample (DM), Conditional Visual Discrimination (CVD), and Concurrent Discrimination (CD). Cumulative performance on DM (mean = 45% correct, n = 2 sessions) and CVD (47%, n = 2 sessions) was lower than that of CD (82%, n = 4 sessions; ANOVA: F(2,5) = 23.67, p < 0.003). The addition of distractors to CD trials caused a 1-session drop in performance, which was recovered in the subsequent session. Siamangs are highly competent using touch-screens, with response latencies during CVD (3.24 sec) consistently longer than those of DM (1.55 sec) and CD (1.69 sec; ANOVA: F(2,5) = 12.39, p = 0.012). These data suggest that hylobatids are as cognitively capable as rhesus macaques (Macaca mulatta) and may possess cognitive abilities approaching some great ape species. This study provides pioneering data demonstrating the poorly-studied cognitive abilities of hylobatids, and also provides critical comparative information for evolutionary evaluation of the primate brain.