Ordering of the numerosities 1 to 9 by monkeys.

Bibliographic Collection: 
MOCA Reference, APE
Publication Type: Journal Article
Authors: Brannon, E M; Terrace, H S
Year of Publication: 1998
Journal: Science
Volume: 282
Issue: 5389
Pagination: 746-9
Date Published: 1998 Oct 23
Publication Language: eng
ISSN: 0036-8075
Keywords: Animals, Discrimination (Psychology), Macaca mulatta, Mathematics, Mental Processes

A fundamental question in cognitive science is whether animals can represent numerosity (a property of a stimulus that is defined by the number of discriminable elements it contains) and use numerical representations computationally. Here, it was shown that rhesus monkeys represent the numerosity of visual stimuli and detect their ordinal disparity. Two monkeys were first trained to respond to exemplars of the numerosities 1 to 4 in an ascending numerical order (1 --> 2 --> 3 --> 4). As a control for non-numerical cues, exemplars were varied with respect to size, shape, and color. The monkeys were later tested, without reward, on their ability to order stimulus pairs composed of the novel numerosities 5 to 9. Both monkeys responded in an ascending order to the novel numerosities. These results show that rhesus monkeys represent the numerosities 1 to 9 on an ordinal scale.

Alternate Journal: Science
Related MOCA Topics: