Red and blue lights flash. A machine whirs like a distant swarm of bees. In a cubicle-sized room, Yoav Adam, a microscope, and a video projector capture something no one has ever seen before: neurons flashing in real time, in a walking, living creature.

For decades scientists have been searching for a way to watch a live broadcast of the brain. Neurons send and receive massive amounts of information—Toe itches! Fire hot! Garbage smells!—with impressive speed. Electrical signals can travel from cell to cell at up to 270 miles per hour.

But, neural electricity is just as hard to see as electricity in a telephone wire: To the unassisted eye, the busy brain looks as lifeless as rubber. So, to observe how neurons turn information (toe itches) into thoughts (“itching powder”), behaviors (scratching), and emotions (anger), we need to change the way we see.