That is why I’m now allowing Michael Weisend, who works at the Mind Research Network in Albuquerque, New Mexico, to hook my brain up to what’s essentially a 9-volt battery. He sticks the anode – the positive pole of the battery – to my temple, and the cathode to my left arm. “You’re going to feel a slight tingle,” he says, and warns me that if I remove an electrode and break the connection, the voltage passing through my brain will blind me for a good few seconds.
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.