Chimps beat us in short-term memory tests

Chimps are often viewed as a lesser version of a human, with limited mental abilities that can’t match ours. But scientists are discovering that they can have complex talents that not only match but exceed our own capabilities in some areas.

The story of Ai captivated those listening to a presentation yesterday in Boston where the annual meeting of the American Association for the Advancement of Science (AAAS) is under way.

Primate researcher Prof Tetsuro Matsuzawa of Kyoto University explained how the chimp Ai and others he has studied have short-term memory skills that humans can’t come even close to matching.

“Chimps have an extraordinary working memory,” he said yesterday.

His early work with Ai was “the first time it was shown chimps can do tasks while humans can’t”.

Consider the challenge. You touch a button on a screen and the numbers one to 10 flash up in random order in various squares on a grid. You must touch each box in ascending order, but as soon as you touch number one all others are hidden from view. It is a test of working memory to touch the grid squares in proper order.

This would be a challenge for any of us. How remarkable, then, that Ai can do the same thing, even though she also has to recognise the numbers and their proper order. A video documents Ai's skills and similar skills in her son Ayumu. (See vimeo.com).

Memory game

She touches the button and the numbers flash up on the screen. After viewing for no more than half a second she begins, touching the squares in the right order from one to 10 without error. Prof Matsuzawa has tested her with all the numbers up to 19 and she can still accomplish this with no more than a half second’s glance to memorise the positions.

The chimps are not coerced and can choose to participate or not, he said. “The animals come at their own free will. Whether they come or not is completely up to them.”

They know there will be food if they accomplish the task and persist until they have had their fill. “No human can do this at this speed, at this accuracy,” Prof Matsuzawa said.