A team of scientists from Baylor College of Medicine, in the United States, has developed a new brain implant that allows blind people to "see" the shape of the letters, without using their eyes.
According to the Science Alert, the device sends images captured by a camera directly to the brain, through implanted electrodes.
“When we used electrical stimulation to dynamically trace the outline of letters directly in the patients' brains, they were able to 'see' the shapes and correctly identify different letters,” explained Daniel Yoshor, author of the scientific article published recently at Cell.
According to the investigator, patients were able to "see" bright spots or connected lines that formed letters. Instead of treating each electrode as a "pixel" to form the image, the team "traced the outline" of the letters.
"Our inspiration was the idea of drawing a letter in someone's palm," added scientist Michael Beauchamp.
In previous studies, blind patients had already been able to visualize points of light. The challenge of this new experience was to organize these points in identifiable geometric shapes and letters.
To do this, the scientists used electricity to draw on the electrode plate: the electricity passed through the electrodes until a trace was established on the surface of the participant's brain. While receiving the brain stimulus, the participants reproduced the drawings with their fingers on a screen. One of the participants achieved a hit rate higher than 90%.
The developed device is still in its early stages, since the brain is an extremely complex organ and the number of electrodes used is still very small.
The primary visual cortex, the part of the brain that processes images and the location where the electrodes were implanted, contains 500 million neurons. “In our experience, we encourage only a small fraction.”
The team's next step is to work with neuroengineers to develop “sets with thousands of electrodes, so that we can stimulate the brain more precisely”.
“With new hardware, the enhanced stimulus algorithms will help us realize the dream of delivering useful visual information to the visually impaired.”