Researchers from the University of Pittsburgh School of Medicine said in an interview yesterday that, with the help of brainwaves alone, monkeys are able to control robotic arms in order to grab onto and put food in their mouth. The technology behind the experiment could lead to the development of prosthetics powered by brainwaves for disabled people who cannot complete simple tasks. Previous similar experiments used brain-computer interfaces to move mouse cursors across a display, but this technology is not exactly fit for real-world tasks, so the research team thought of a more practical approach.

"They are using a motorized prosthetic arm to reach out, grab and bring the food back to their face", said Andrew Schwartz of the University of Pittsburgh School of Medicine. Brainwaves are picked up with the help of microelectrodes planted in the brain of the subject and then relayed to a computer that converts them into commands leading to the movement of a robotic arm mimicking the natural movements of the limb. This is done by learning the firing pattern of the neurons in the brain, as the monkey wants to execute a certain task.

"What is important is each neuron seems to have a preferred direction. One cell will fire a lot if you move upward. Another cell will fire a lot if you move to the right. All you really need to do is listen to these neurons at the same time to determine which direction the animal wants to move in. We record those patterns of action potential, interpret them with a computer and extract the monkey's intention to move. That serves as a control signal to the robot", said Schwartz.

The learning process takes about three days although once it is completed the monkey continues to improve its abilities. It even seems to enjoy the whole experiment.

"These animals will just relax their arms as they control these devices. They sure like eating their marshmallows", Schwartz said. The technology will ultimately lead to the development of brain-powered prostheses for people with spinal cord injuries or limbs missing. Albeit, until then, there is much room for improvement, especially regarding the dexterity of the robotic arm.

"If you look at what these patients really need, they need to be able to use their fingers to increase their quality of life. They need to button shirts and pull zippers and things like that", Schwartz said.