April 21 : Researchers at Columbia’s Primate Cognition Laboratory have for the first time shown that monkeys can acquire meta-cognitive skills, the ability to reflect about their thoughts and to assess their performance.

They conducted a study to see whether a monkey could express its confidence in its answers to multiple-choice questions about its memory, based on the amount of imaginary currency it was willing to wager.

“The ability to reflect on one’s knowledge has always been thought of as exclusively human. We designed a task to determine if a non-human primate could similarly learn to express its confidence about its knowledge by making large or small wagers,” says Lisa Son, professor of psychology at Barnard College.

The study, published in Psychological Science, was derived from the observation that children often make pretend bets to assert that they know the answer to some question.

Two monkeys were trained to play a video game to test their ability to remember a particular photograph, while also allowing them to make a large or a small bet.

Six novel photographs were presented at the beginning of each trial, one at a time. One photograph was selected at random and then displayed simultaneously with eight novel photographs.

All that the monkeys had to do was to select the photograph that appeared at the beginning of the trial, and then to evaluate the accuracy of its choice by selecting a high and a low-risk icon presented on the screen.

High-risk bets were followed by a reward or loss of 3 tokens, while low-risk bets were always followed by a reward or loss of one token. When the monkey accumulated enough tokens, it was rewarded with food.

The results demonstrated that with the monkeys, there was a strong correlation between high-risk bets and correct responses and between low-risk bets and incorrect responses.

Terrace argues that “the pattern of the monkeys’ bets provided clear evidence of their ability to engage in meta-cognition, an ability that is all the more remarkable because monkeys lack language.”

The researchers, however, say that the new findings may have far reaching implications as well.

“Our results are of general interest because non-verbal tests of the type used in this and other experiments on animal cognition can be adapted to study cognitive abilities of infants and autistic children,” Terrace notes. (ANI)