Scientists ‘Inject’ Information Into The Brains Of Monkeys

Two neuroscientists at the University of Rochester say they have managed to introduce information directly into the premotor cortex of monkeys‘ brains. This new research could eventually help people who have had strokes.

The researchers published the results of the experiment on Thursday in the journal Neuron. Although the research is preliminary and carried out in just two monkeys, the researchers speculated that further research and studies might lead to brain implants for people with strokes.

“You could potentially bypass the damaged areas and deliver stimulation to the premotor cortex,” said Kevin A. Mazurek, a co-author of the study. “That could be a way to bridge parts of the brain that can no longer communicate.”

According to the New York Times, in order to study the premotor cortex of monkeys, Dr. Mazurek and his co-author, Dr. Marc H. Schieber, trained two rhesus monkeys to play a game. The monkeys sat in front of a panel equipped with a button, a sphere-shaped knob, a cylindrical knob, and a T-shaped handle. Each object was ringed by LED lights. If the lights around an object switched on, the monkeys had to reach out their hand to it to get a reward — in this case, a refreshing squirt of water.

Each object required a particular action. If the button glowed, the monkeys had to push it. If the sphere glowed, they had to turn it. If the T-shaped handle or cylinder lit up, they had to pull it. After the monkeys learned how to play the game, Dr. Mazurek and Dr. Schieber had them play a wired version. The scientists placed 16 electrodes in each monkey’s brain, in the premotor cortex. Each time a ring of lights switched on, the electrodes transmitted a short, faint burst of electricity. The patterns varied according to which object the researchers wanted the monkeys to manipulate. As the monkeys played more rounds of the game, the rings of light dimmed. At first, the dimming caused the monkeys to make mistakes. But then their performance improved. Eventually the lights went  out completely, yet the monkeys were able to use only the signals from the electrodes in their brains to pick the right object and manipulate it for the reward. And they did just as well as with the lights. This hints that the sensory regions of the brain, which process information from the environment, can be bypassed altogether. The brain can devise a response by receiving information directly, via electrodes.  –The New York Times

Neurologists have long known that applying electric current to certain parts of the brain can make people involuntarily jerk certain parts of their bodies, however, this isn’t what these monkeys experienced.  Dr. Mazurek and Dr. Schieber were able to rule out this possibility by seeing how short they could make the pulses. With a jolt as brief as a fifth of a second, the monkeys could still master the game without the lights without the jerking about.

“The stimulation must be producing some conscious perception,” said Paul Cheney, a neurophysiologist at the University of Kansas Medical Center, who was not involved in the new study.  Dr. Schieber speculated that someday scientists might be able to use such advanced electrodes to help people who suffer brain damage. Strokes, for instance, can destroy parts of the brain along the pathway from sensory regions to areas where the brain makes decisions and sends out commands to the body. Implanted electrodes might eavesdrop on neurons in healthy regions, such as the visual cortex, and then forward information into the premotor cortex.