MIT computer geek Arlene Ducao has seen such a future. Ducao, a computer programmer and digital animator at the MIT Media Lab’s Information Ecology group, is shown wearing MindRider a bicycle helmet hacked with an EEG sensor that displays the wearer’s stress levels so that idiot in the Escalade knows to back off.

“It indicates your mental state by flashing a visual vocabulary of traffic lights,” says Ducao. “Green is low stress, red is high stress and blinking lights indicate panic.”

Ducao had previously designed helmets with manual lighting, but realized a hands-free solution was preferable. The MindRider uses a NeuroSky MindSet, picking up 10 types of brainwaves that signal emotions such as concentration, fear and anxiety. An Arduino microcontroller translates these signals into a series of light values, causing a strip of embedded LED lights to change color according to input.