For the very first time, scientists have demonstrated that a brain implant can improve thinking ability in primates. By implanting an electrode array into the cerebral cortex of monkeys, researchers were able to restore — and even improve — their decision-making abilities. The implications for possible therapies are far-reaching, including potential treatments for cognitive disorders and brain injuries. But there’s also the possibility that this could lead to implants that could boost your intelligence. Here’s how they did it.
Researchers from Wake Forest Baptist Medical Centre, University of Kentucky, and University of Southern California took five rhesus monkeys and trained them on a delayed match-to-sample task. This involved tracking images of toys, a person, and a mountain range that were flashing on a large screen. Following a delay, the monkeys had to select the same image on the screen from a group of one to seven images. The monkeys were trained to work on this task for the past two years, and they managed to acquire a proficiency of around 75%.
The researchers, a team led by Sam Deadwyler and Robert Hampson, then monitored the brain activity of the monkeys to confirm the location of the areas required for decision making. They paid particular attention to those areas that lit up when the monkeys were successful at the matching game.
To do so, they used a tiny probe with two sensors that was threaded through the monkeys’ forehead and into their cerebral cortex (specifically between two cortical layers of the brain), thus allowing them to record activity in the prefrontal cortex.
Once they were satisfied that the correct mapping had been done, they administered cocaine to the monkeys to impair their performance on the match-to-sample task (seems like a rather severe drug to administer, but there you have it). Immediately, the monkeys’ performance fell by a factor of 20%.
It was at this point that the researchers engaged the neural device. Specifically, they deployed a “multi-input multi-output nonlinear” (MIMO) model to stimulate the neurons that the monkeys needed to complete the task. The inputs of this device monitored such things as blood flow, temperature, and the electrical activity of other neurons, while the outputs triggered the individual neurons required for decision making. Taken together, the i/o model was able to predict the output of the cortical neurons — and in turn deliver electrical stimulation to the right neurons at the right time.
And incredibly, it worked. The researchers successfully restored the monkeys’ decision-making skills even though they were still dealing with the effects of the cocaine. Moreover, when duplicating the experiment under normal conditions, the monkeys’ performance improved beyond the 75% proficiency level shown earlier. In other words, a kind of cognitive enhancement had happened. Via Scientists make monkeys smarter using brain implants. Could you be next?.