Abstract

Imagine this scene from the future. You are staring at a screen flickering with snow. Scientists have hidden one of two patterns in the dots, and eventually you spot one. But you don't have to tell the scientists what you are seeing; they already know. They are looking at the electrical signals from one of the billions of cells in your brain. When the cell fires, you see one pattern; when it stops, you see another‹your awareness can be read from a single neuron. Now, in an even more unsettling trick, they send an electrical current to the neurons in that part of your brain and, with a push of a button, make you see one pattern or the other.