Abstract # 2834 Event # 126:

Scheduled for Saturday, June 19, 2010 09:45 AM-09:55 AM: Session 20 (Medallion Ballroom B) Oral Presentation


GRAMMAR RULE-BASED SEQUENCE LEARNING BY RHESUS MACAQUES (MACACA MULATTA)

L. A. Heimbauer1,2, C. M. Conway3, M. H. Christiansen4, M. J. Beran1,2 and M. J. Owren1,2
1The Language Research Center, Department of Psychology, Georgia State University, University Plaza, Atlanta, GA 30303, USA, 2Georgia State University, 3Saint Louis University, 4Cornell University
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Our previous experiments with rhesus macaques (Macaca mulatta) revealed learning of visually based sequences of up to eight items, comparable in length to sequences used in analogous human studies. To investigate sensitivity to underlying structure of grammar-like rules in visual sequences, we exposed two monkeys (Obi and Luke) to sequences of length four (SL4), based on simple rules [90% of trials] or generated quasi-randomly [10% of trials]. Each trial involved using a joystick to track a colored circle as it appeared in any of four positions on a computer monitor, using mean latencies across and within sequences as the performance measure. After 32 sessions, t-test results showed both individuals’ mean latencies to be statistically faster on rule-based than random sequences [P<0.001]. To test for sensitivity to the underlying rules involved, the second experiment added eight novel sequences to each session – four sequences produced by each monkey’s familiar rule [10% of trials] and four produced by an unfamiliar rule [10% of trials]. After only three sessions, both monkeys showed significantly faster performance on novel, familiar sequences than on novel sequences from an unfamiliar rule [Obi, P<0.01; Luke, P<0.05]. Overall, results suggest rhesus monkeys can be sensitive to underlying rules in short sequences, which may parallel the implicit-learning abilities humans draw on when learning grammar in language.