Abstract # 180:

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

Chimpanzees’ (Pan troglodytes) strategies for managing concurrent, asymmetric spatial relations in an insertion task

N. M. Scott1, D. Fragaszy1 and C. Menzel2
1University of Georgia, Neuroscience and Behavior Program, Psychology Department, Athens, GA 30606, USA, 2Georgia State University
     Solving spatial problems requires managing relations between objects and surfaces. Managing concurrent relations between an object and a surface should be more difficult than managing a single relation. Four adult chimpanzees inserted a rigid stick into a groove on a tray before returning the tray to the experimenter. The number of concurrent relations required for insertion increased as the task changed progressively from a straight line, to a cross, to a tomahawk shape. Subjects completed 10 trials of each shape before progressing to the next. We coded from videotape angular and positional variables about each placement of the stick against the tray. A subset of the data collected is presented here. All subjects completed the series but, in a manner distinct from adult humans (i.e., direct placement into the groove) and with much less efficiency (i.e. greater time and number of attempts to completion). Our prediction was supported; chimpanzees took 20 times as long with 10 times the attempts to complete the task in the asymmetric condition compared to baseline and straight stick conditions. Specific strategies emerged as the number of concurrent relations increased; for instance, bimanual placement of the stick to the tray increased from the straight stick condition to the tomahawk shape condition. This study illustrates the capacity of the chimpanzee intellect to match objects to a specific use. Supported by grant HD38051 to Georgia State University.