We've all been there, exhausted but with so much work to do before we can actually go to sleep. For most people, the solution lies in coffee or less universally legal stimulants, but US Air Force staff are made of sterner stuff. Forty of them volunteered to see if they could fight fatigue through electrical stimulation, and results suggest they might be onto something.
Before you put your finger in a power point or ask a buddy to taser you it's important to be aware this does not involve just any old electric shock. Instead, the study, published in Communications Biology, applied either mild electric currents or a placebo to participants' vagus nerves, which connect the brain to the gut.
There's increasing evidence this nerve triggers parts of the brain involved in consciousness. Consequently, it is not altogether surprising scientists from the company Infoscitex found stimulating it helped sleep-deprived participants maintain better focus, as well as maintaining a capacity for multi-tasking.
Participants in the study had to stay awake for 34 hours, with regular testing of their alertness. They were first tested around 10 hours after they woke, and had their vagus nerves stimulated (or not) three hours later, followed by seven more rounds of testing. The stimulation used 25 Hz pulses for four sets of two minutes each using gammaCore, a device already approved by the FDA for self-treatment of migraines and cluster headaches.
Research psychologist at Infoscitex Corporation Lindsey McIntire and co-authors report those getting the stimulation showed a significantly lower decrease in performance as the trial went on. The biggest difference came 12 hours after the stimulation when those who got the placebo were performing 15 percent below normal, while those with the real treatment were only down 5 percent. Both groups were asked to self-assess how tired they were, with the treated group reporting substantially less fatigue.
As the paper notes, fatigue can be lethal; sleep deprivation can be as bad for drivers as being drunk. At least for some people, vagus nerve stimulation might prove more effective than coffee consumption, with fewer side effects. Making it so pleasurable we will build an immense global industry around delivering the perfect vagus stimulation seems less likely, but who can tell?
The vagus nerve itself doesn't control fatigue, but it connects to the locus coeruleus (LC), a brain region thought to play a major role in regulating wakefulness and attention, as well as memory formation and retention. Methods to stimulate the LC through the skull exist but are best applied by a trained technician. The authors hoped that by stimulating the vagus nerve they would trigger the desired responses in the LC, and it appears they have.
Nevertheless, 40 participants is not exactly a huge sample size. In addition, most of the authors come from Infoscitex, a company that contracts to the US military, rather than a public research institution, although they declare “no competing interests” in the paper.