Rhesus Monkeys Used To Test Cybernetic Implant
September 17, 2012

Brain Implant Could Increase Cognitive Function Of Dementia, Stroke Patients

redOrbit Staff & Wire Reports - Your Universe Online

Scientists are developing an implant that can allow them to manipulate the neural activity of rhesus monkeys, allowing them to help regain lost decision-making processes in the primates and providing a technological device which could someday help those suffering from dementia, stroke, cerebral injury or various brain diseases.

A team of researchers hailing from the University of Southern California (USC), the University of Kentucky, and Wake Forest Baptist Medical Center created the cybernetic implant. That implant, explains Jason Mick of Daily Tech, is comprised of an electrode prosthesis which is connected to two parts of the monkey's neural cortex.

The device allowed them to "manipulate the neural activity of rhesus monkeys to assist them with decision-making when their cognitive abilities were impaired due to the administration of cocaine," Joseph Stromberg of the Smithsonian's Surprising Science blog added.

As part of their research, which has been published in the Journal of Neural Engineering, the scientists first trained the monkeys to complete a simple task involving matching images on a computer screen, Stromberg said. They monitored the rhesus monkeys, and rewarded each successful effort with a drop of juice from a nearby sipper.

"Over the course of several months, each monkey got the hang of the task and trained until they were able to select the correct image 40 to 75 percent of the time, depending on the number of photos shown," Stromberg said, noting that the team was "closely monitoring the monkeys´ neural patterns with recording cylinders that had been implanted in the animals´ prefrontal cortex, an area of the brain known to be active during decision-making tasks."

They then began injecting the monkeys with cocaine, a drug known for negatively impacting concentration and decision-making skills, while they were in the midst of completing their tasks. The intoxicated animals saw their success rate decrease by 13%, the Smithsonian writer said. Use of the electrodes not only reversed those negative effects, but "actually improved the monkey's memory above the original baseline," according to Mick.

The device is implanted through the forehead of the monkeys, and into the L-2/3 and L-5 layers of the brain's thin outer covering, also known as the cerebral cortex, explained New York Times writer Benedict Carey. Those two layers send signals back and forth when the brain is required to make decisions, much like the creatures were asked to do during the computer-based matching game.

"The research team believes the device could represent the prototype for an assistive device for those who have had brain injuries, strokes, or suffer from neurodegenerative diseases, and may help such people complete basic tasks," Jon Bardin of the Los Angeles Times said. "But much more work needs to be done before it is clear exactly how useful such a device would be."

"The results suggest that neural implants could one day be used to recover specific brain functions in patients with brain injuries or localized brain disease," added Technology Review's Susan Young. "While the results“¦ may take many years to translate into humans, they suggest that even cognitive processes, such as deciding whether or not to grab a cup of coffee or remembering where you left your keys, could one day be augmented by brain chips."