A Brain Implant that Thinks

Researchers have used a neural implant to recapture a lost decision-making process in monkeys—demonstrating that a neural prosthetic can recover cognitive function in a primate brain. 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.
 
While the results of today’s study 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.
 
Paralyzed patients have previously used brain implants and brain-machine interfaces to control robotic arms (see "Brain Chip Helps Quadriplegics Move Robotic Arms with Their Thoughts"). And more than 80,000 Parkinson’s patients around the world have a deep-brain stimulation implant, which functions like a pacemaker to reduce their tremors and other movement problems (see "Brain Pacemakers"). In the new study, however, the implants could actually interpret neuronal inputs from one part of the brain and effectively communicate those outputs to another brain region.   
 
The researchers used an array of electrodes to record the electrical activity of neurons in the prefrontal cortex of monkeys while they performed a memory task. The prefrontal cortex is involved in decision making and directs many types of cognitive responses associated with memory or other types of information processing.
 
The five monkeys in the study were trained to play a matching game in which they were shown an image on a screen and then had to use hand movements to steer a cursor to that same image out of two to seven others that they were shown anywhere from one to 90 seconds later.
 
This kind of movement decision is different than a simple reflexive movement. "The monkeys have to find out where the image is and then select the kind of movement to move the cursor there," says Sam Deadwyler, a brain scientist at Wake Forest Baptist Medical Center in Winston-Salem, North Carolina, and a senior author on the study.