We tested cotton-top tamarin monkeys on various spatial tasks to determine the nature of their representations of landmarks and to explore the limits of nonlinguistic concepts. We considered spatial knowledge as a cognitive domain, and thus sought to characterize the rules and constraints guiding behavior and response to environmental cues. The thesis presents three experiments. The first is a replication of studies done by Cheng (1986) and Hermer and Spelke (1996), testing whether the tamarins can conjoin geometric and nongeometric featural properties of landmarks upon disorientation. We found that adult tamarins use featural cues when disoriented, suggesting that they may be able to conjoin information processed in separate modules. The second experiment builds on the first, the task demanding that the monkey conjoin information about a landmark and its relation to a goal. The monkeys learned to search above or below a particular object. Once the relation was learned, we altered features of the object to see what changes affected the monkeysâ preference for using it as an indicator of the goal. We also manipulated the context of the task upon test to investigate whether the monkeys could generalize the rule. We found that the tamarins attend to landmark shape preferentially over color and orientation, and that the monkeys generalized the rule to novel contexts, indicative of a relatively flexible representation. Finally, the third experiment examines tamarinsâ ability to form and use abstract concepts of geometric configurations. We trained the subjects to search midway between two landmarks for food, then tested them with manipulations in the configuration including expansions of inter-landmark distance, rotations of the configurationâs orientation, and translations across a plane. We found limited evidence that tamarins can understand "middle" and generalize this concept to a certain extent, but we were prevented from making general claims because of a limited sample size. In summary, we found that though the tamarins lack the elaborative power of language, nonetheless they are able to form and use some abstract, complex spatial representations. They attend to geometric and nongeometric features of landmarks, using both to forage efficiently during spatial tasks.

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General Introduction
General Methods
General Conclusion ÿ