Researchers at Wake Forest Baptist Medical Center and the University of Southern California improved thinking and restored decision-making in five monkeys using an electrode array implanted into their prefrontal cortex—the area of the brain responsible for planning and decision-making.
In the study, published last week (September 13) in The Journal of Neural Engineering, researchers probed the monkey’s cerebral cortex in order to map neuron activity as they played an image matching game, which they learned to play with 75 percent accuracy. In the game, monkeys were presented with an image—of either a person, a toy, or mountains—that they would have to identify a few moments later from a collection of images. If they identified the image correctly, they would get a treat as researchers took note of which neurons had fired.
After the researchers mapped the neural pathway that led to a correct answer, they inserted a stimulator into the monkey’s brains that could trigger that pathway. They then impaired the monkey’s cognitive abilities by giving them cocaine—which caused their scores to go down 20 percent—and restored their performance by triggering the mapped neural pathway with the stimulator. When the researchers repeated the experiment without the drug impairment, they found that monkeys scored higher than their 75 percent average.
“When you turn on the stimulator, they don’t make those errors; in fact, they do a little better than normal,” Wake Forest’s Robert E. Hampson, lead author of the study, told The New York Times.
Though the technology is years away from commercialization, the success of the brain prosthesis in the monkeys—which have a similar brain structure to humans—could fuel efforts to restore cognitive ability in people with brain damage.