Monkey See, Monkey Feel

The ability to touch and feel things is one of our most important sensory inputs; so important that there is a Divinyls song about it. There are people around the world, however, who have to live without this fundamental sense.

New research from the University of Chicago is hoping to change that by developing new ways to send the information to the brain that skips the normal pathways. This could potentially allow people with prosthetic limbs to have a sense of touch.

In the research, published in the Proceedings of the National Academy of Science in the United States of America, scientists trained Rhesus monkeys (technically Rhesus macaques) to perform specific actions whenever they felt different physical sensations.

For example when they felt a prodding on their index finger they would look in one particular direction and when they felt a prodding on their ring finger they would look in a different direction.

Microelectrodes were placed on the monkeys’ brains that recorded the different brain activity and patterns that occurred when the monkeys felt the prodding on either of the fingers.

The scientists were then able to directly stimulate the brain to produce identical patterns causing the monkeys to react as if they had been prodded on the finger.

Building on this, the scientists were able to simulate different levels of touch, like having the monkeys perceive feeling a slight tap or a sharp jab by the direct brain stimulation.

The scientists hope that this research will help lead to the development of better prosthetic limbs that are able to transmit a feeling of touch directly to the brain like natural limbs do. They do point out that there is a lot of work to do. While electrode implants in humans have been shown to be safe, scientists aren’t sure how effective they are in the human brain over long-term periods of multiple years.