Not only can the monkeys choose which image came first in the same list, but they can also compare the order of pictures that came from different lists, found the researchers. The scientists said they have not yet found the limits of the monkeys' learning capacity.
The researchers -- Herbert Terrace of Columbia University, Lisa Son of Barnard College and Elizabeth Brannon of Duke University -- reported their findings in an article in the January 2003 Psychological Science. Son and Brannon were graduate students at Columbia when the study was conducted. The scientists' research was sponsored by the National Institute of Mental Health and the National Science Foundation. Brannon is an assistant professor in the Department of Psychological and Brain Sciences and a member of Duke's Center for Cognitive Neuroscience.
"While quite a lot of research has been done in monkeys addressing specific cognitive abilities such as numerical cognition or concept formation, very little has been done up to this point on the development of expertise," said Brannon.
To explore how monkeys learn, the researchers decided to teach four rhesus macaque monkeys -- named Benedict, Macduff, Oberon and Rosencrantz -- to distinguish the order of images displayed on a video touch screen. In the experiments, the monkeys were first presented with sets of images such as animals, people, scenery, cars and bridges. In return for banana-pellet rewards, the monkeys were then required to touch the images in a particular arbitrary but consistent order. The pictures were presented in random positions on the screen in each tria
Contact: Dennis Meredith