Nov 25, 2011 11:25 PM GMT
Things that make you go hmmm...
One of the most difficult tasks to teach Air Force pilots who guide unmanned attack drones is how to pick out targets in complex radar images. Pilot training is currently one of the biggest bottlenecks in deploying these new, deadly weapons.
So Air Force researchers were delighted recently to learn that they could cut training time in half by delivering a mild electrical current (two milliamperes of direct current for 30 minutes) to pilot's brains during training sessions on video simulators. The current is delivered through EEG (electroencephalographic) electrodes placed on the scalp. Biomedical engineer Andy McKinley and colleagues at the Air Force Research Laboratory at Wright–Patterson Air Force Base, reported their finding on this so-called transcranial direct current stimulation (TDCS) here at the Society for Neuroscience annual meeting on November 13.
"I don't know of anything that would be comparable," McKinley said, contrasting the cognitive boost of TDCS with, for example, caffeine or other stimulants that have been tested as enhancements to learning. TDCS not only accelerated learning, pilot accuracy was sustained in trials lasting up to 40 minutes. Typically accuracy in identifying threats declines steadily after 20 minutes. Beyond accelerating pilot training, TDCS could have many medical applications in the military and beyond by accelerating retraining and recovery after brain injury or disease.
The question for the Air Force and others interested in transcranial stimulation is whether these findings will hold up over time or will land in the dustbin of pseudoscience.
"There is so much pop science out there on this right now," says neurobiologist Rex Jung of the University of New Mexico Health Sciences Center in Albuquerque, referring to sensational media reports, the widely varying protocols and sometimes lax controls used in different studies of brain stimulation to power learning or elevate mood.
Indeed, electrical stimulation for therapeutic effect has a long and checkered history extending back to the 19th century when "electrotherapy" was the rage among adventurous medical doctors as well as quacks. Pulses of electric current were applied to treat a wide range of conditions from insomnia to uterine cancer. The placebo effect might have been at work in the case of those historical results, and although the experiments were carefully controlled, it is unclear to skeptics if it is a factor in the case of the Air Force's research on transcranial stimulation and learning.
Subjects definitely register the stimulation, but it is not unpleasant. "It feels like a mild tickling or slight burning," says undergraduate student Lauren Bullard, who was one of the subjects in another study on TDCS and learning reported at the meeting, along with her mentors Jung and Michael Weisend and colleagues of the Mind Research Network in Albuquerque. "Afterward I feel more alert," she says. But why?