A brain device that can increase learning by up to 40 percent has been revealed by scientists funded by the Defense Advanced Research Project Agency (DARPA). While the device was originally tested on macaques, researchers said it could be a cheap and non-invasive way of “altering functional connectivity in humans” in the future.
The device is a non-invasive cap that stimulates parts of the brain via electrical currents. It was developed by researchers at HRL Laboratories, California, McGill University in Montreal, Canada, and Soterix Medical in New York.
In their experiments, the team performed “non-invasive transcranial direct current stimulation”—or tDCS—on a set of macaques. They stimulated the prefrontal cortex and got them to perform a task based on associative learning. In order to get a reward, they had to learn associations between a visual cue and a location. The macaques would forage for the reward after getting the visual cue.
The findings, published in the journal Current Biology, showed that macaques in the control group took 22 trials before they had learned to get the reward straight away. It took the tDCS group just 12 trials. The tDCS device accounted for a 40 percent increase in learning speed, the authors say.
“In this experiment we targeted the prefrontal cortex with individualized non-invasive stimulation montages,” principal investigator Praveen Pilly, from HRL, said in a statement. “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.”
Their findings showed the simulation caused changes to the connections of different brain areas and that it was this increased connectivity, rather than neuron firing rates, that led to the improved performance. “The improved long-range connectivity between brain areas in the high frequency bands and reduced connectivity in the low frequency bands were the determining factors in our study that could explain the learning improvements,” Pilly said.
Concluding, the team wrote: “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.”
The research was carried out as part of DARPA’s Restoring Active Memory (RAM) program. This research focuses on traumatic brain injury that results in a person being unable to retrieve memories. DARPA is looking to speed up the development of technologies that allow scientists to help those affected by this by “developing new neuroprosthetics to bridge gaps in the injured brain.”
Eventually, it hopes to develop a wireless, implantable interface that can restore memories and memory function in people affected.