Abstract # 4441 Event # 45:

Scheduled for Thursday, June 20, 2013 04:00 PM-04:15 PM: Session 7 (Las Olas) Oral Presentation


KEEPING TRACK OF WHAT WENT WHERE: CHIMPANZEES (PAN TROGLODYTES) ACCURATELY JUDGE CONCURRENTLY ACCUMULATING QUANTITIES

M. J. Beran
Language Research Center, Georgia State University, Decatur, GA 30034, USA
line
     Although some primates can judge two sequentially presented sets of food items, rarely has food accumulation alternated between the sets throughout the trial. Rather, each set is presented to completion, or subsets are added to each choice set at discrete times. Four chimpanzees (Pan troglodytes) observed as 1 to 9 food items accumulated in each of two containers through random placement of each item into either set. All chimpanzees succeeded in selecting the larger set (p < .05, binomial test) although performance indicated that this was a more difficult version of the task than those noted above. In the next test, three containers were used for random food placement. Performance was lower, but still exceeded chance (p < .05, binomial test), indicating that chimpanzees can judge three concurrently accumulating sets through use of enumeration or summation of stimuli that are presented in a complex sequential manner. Adult humans (Homo sapiens) were given a computerized version of this task to compare their performance to that of the chimpanzees. Although human performance was higher overall than the performance of the chimpanzees, both species showed similar error patterns. Typically, errors were made by choosing the second-largest set instead of the largest set, particularly when those two sets were close to each other in terms of their quantities. Supported by NIH (HD060563).