A new, non-invasive technique has been developed by researchers working for the Defense Advanced Research Projects Agency (DARPA) that can boost the brain’s cognitive ability by up to 40 percent.

The international team, working under DARPA’s Restoring Active Memory (RAM) program, has tested the device on macaques, using a technique called transcranial direct current stimulation (tDCS), to stimulate the prefrontal cortex of the test monkeys. tDCS makes use of electrodes that are placed on the scalp to deliver a low-current electrical charge to the brain, and has been used to help alleviate symptoms of depression in human patients. The researchers found that the technique improved the macaques’ associative learning abilities, improving their learning speed by 40 percent.

The researchers found that rather than affecting the rate that individual neurons were firing at, the technique improved interconnectivity between different areas of the brain, improving overall communication between different centers.

"In this experiment, we targeted the prefrontal cortex with individualized non-invasive stimulation montages," explains lead HRL Laboratories researcher Praveen Pilly. "That is the region that controls many executive functions, including decision-making, cognitive control, and contextual memory retrieval. It is connected to almost all the other cortical areas of the brain, and stimulating it has widespread effects."

As the program’s name might suggest, DARPA’s goal isn’t necessarily to boost the brain’s cognitive functions, but rather to develop a treatment for individuals suffering from memory loss, due to neural degeneration. Nonetheless, this otherwise unintended benefit could prove to be very useful for future medical applications.

"These results are consistent with the idea that tDCS leads to widespread changes in brain activity and suggest that it may be a valuable method for cheaply and non-invasively altering functional connectivity in humans," according to the team’s research paper, published in the journal, Current Biology.