Blind people can pick up letters drawn directly in their brains!

Scientists have developed a new way to create “sights” for blind people, it’s like writing in the sky, but instead of blue sky, the letters are written in the brain itself. The new approach bypasses the eyes and sends a sequence of electrical signals to the brain, creating the perception of bright light tracing a shape; With further refinements, the method could one day restore aspects of vision for people with damaged eyes or optic nerves. Scientists have been able to create artificial visions by manipulating the brains of mice, but progress for people has been slower.

Tiny jolts of electricity in the visual cortex, a stretch of neural tissue at the back of the brain, can cause a person to see tiny flashes of light called phosphenes. Previous attempts to restore vision involved creating multiple phosphenes at the same time, like movie marquee bulbs, but those signals were difficult to interpret, forming shards of lights or a blur of fused lights.

A clearer signal comes from using electricity like a pencil, essentially drawing lines in the visual cortex with electrical current. In tests with six volunteers, who had electrode grids implanted in their brains, the researchers activated the electrodes in a sequence that traced the lines of the letters of the alphabet; the process is similar to someone writing the letter N on someone’s palm by making a line up, then a plummet, then back up.

This sequential writing method allowed participants to quickly perceive the intended shapes, they could recognize 86 shapes per minute with the technique. So far, the researchers have tested only simple shapes, such as the letters C, W, and U, but the outlines of common objects, such as faces, houses, or cars, could be traced using the same idea, the researchers write.