Weisend, who is working on a US Defense Advanced Research Projects Agency programme to accelerate learning, has been using this form of transcranial direct current stimulation (tDCS) to cut the time it takes to train snipers. From the electrodes, a 2-milliamp current will run through the part of my brain associated with object recognition - an important skill when visually combing a scene for assailants.
Mysteriously, however, these long-term changes also seem to be preceded by a feeling that emerges as soon as the current is switched on and is markedly similar to the flow state. "The number one thing I hear people say after tDCS is that time passed unduly fast," says Weisend. Their movements also seem to become more automatic; they report calm, focused concentration - and their performance improves immediately.
The journalist goes from
I'm close to tears behind my thin cover of sandbags as 20 screaming, masked men run towards me at full speed, strapped into suicide bomb vests and clutching rifles. For every one I manage to shoot dead, three new assailants pop up from nowhere. I'm clearly not shooting fast enough, and panic and incompetence are making me continually jam my rifle.
My salvation lies in the fact that my attackers are only a video, projected on screens to the front and sides. It's the very simulation that trains US troops to take their first steps with a rifle, and everything about it has been engineered to feel like an overpowering assault. But I am failing miserably. In fact, I'm so demoralised that I'm tempted to put down the rifle and leave.
I simply begin to take out attacker after attacker. As twenty of them run at me brandishing their guns, I calmly line up my rifle, take a moment to breathe deeply, and pick off the closest one, before tranquilly assessing my next target.
In what seems like next to no time, I hear a voice call out, "Okay, that's it." The lights come up in the simulation room and one of the assistants at Advanced Brain Monitoring, a young woman just out of university, tentatively enters the darkened room.
In the sudden quiet amid the bodies around me, I was really expecting more assailants, and I'm a bit disappointed when the team begins to remove my electrodes. I look up and wonder if someone wound the clocks forward. Inexplicably, 20 minutes have just passed. "How many did I get?" I ask the assistant.
She looks at me quizzically. "All of them."
Zapping your brain with a small current seems to improve everything from mathematical skills to marksmanship, but for now your best chance of experiencing this boost is to sign up for a lab experiment. Machines that provide transcranial direct current stimulation (tDCS) cost £5000 a pop, and their makers often sell them only to researchers.
That hasn't stopped a vibrant community of DIY tDCS enthusiasts from springing up. Their online forums are full of accounts of their home-made experiments, including hair-curling descriptions of blunders that, in one case, left someone temporarily blind.