Swim caps with electrodes. That was the secret all along.
So far there have been no paralyzing flashbacks to Kaiju attacks, or false memories of being someone named Douglas Quaid. But at the University of Washington, one guy was able to make another guy's finger move involuntarily to the "fire" button on his keyboard.
Rao looked at a computer screen and played a simple video game with his mind. When he was supposed to fire a cannon at a target, he imagined moving his right hand (being careful not to actually move his hand), causing a cursor to hit the "fire" button. Almost instantaneously, Stocco, who wore noise-canceling earbuds and wasn't looking at a computer screen, involuntarily moved his right index finger to push the space bar on the keyboard in front of him, as if firing the cannon. Stocco compared the feeling of his hand moving involuntarily to that of a nervous tic.
I think we all see the ramifications for the next James Bond film's plot, don't you?