Air Date: Week of May 13, 2005

Living on Earth's Katie Zemtseff reports on a study that suggests monkeys consider tools an extension of themselves.

Transcript

CURWOOD: Just ahead, the environment as a casualty of the immigration conflict. First, this Note on Emerging Science from Katie Zemtseff.

ZEMTSEFF: We know that monkeys are a lot like humans, but who would have thought they’d like video games too? They not only like them, but after being trained to play; the monkeys actually consider the joystick another limb.

Researchers at Duke University taught two female rhesus monkeys to use a joystick to play a video game where they moved a cursor over a target. They also installed microelectrodes into the monkey’s brains and studied how their brain signals controlled their arm movements. Researchers then added forces to the cursor such as resistance and momentum, so the monkeys actually felt like they were lifting and pushing the cursor as they would a real arm. Then scientists took the joystick away and electronically connected the monkey’s brains to a robotic arm that controlled a second joystick. When the monkeys then tried to move the cursor, they first waved their arm, but soon realized their brain could do all the work.

Turns out some of the brain cells that had formerly controlled the monkey’s real arm had figured out how to control the robotic arm using only brain signals. Scientists think the monkeys recognized the joystick not only as a tool, but also as an extension of their own arms. These researchers believe humans, like monkeys, are good at using tools because our brains think of tools as extensions of our bodies, although this theory has yet to be tested on people.

That’s this week’s Note on Emerging Science, I’m Katie Zemtseff.

CURWOOD: And you’re listening to Living on Earth.