New finding may help restore vision in the blind

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Restoration of vision in blind people through a brain implant is on the verge of becoming reality.

In a new study, researchers found that newly developed high-resolution implants in the visual cortex make it possible to recognize artificially induced shapes and percepts.

The research was conducted by a team at the Netherlands Institute for Neuroscience (NIN).

The idea of stimulating the brain via an implant to generate artificial visual percepts is not new and dates back to the 1970s.

However, existing systems are only able to generate a small number of artificial ‘pixels’ at a time.

In the study, the team is using new implant production and implantation technologies, cutting-edge materials engineering, microchip fabrication, and microelectronics, to develop devices that are more stable and durable than previous implants. The first results are very promising.

When electrical stimulation is delivered to the brain via an implanted electrode, it generates the percept of a dot of light at a particular location in visual space, known as a ‘phosphene.”

The team developed high-resolution implants consisting of 1024 electrodes and implanted them in the visual cortex of two sighted monkeys.

Their goal was to create interpretable images by delivering electrical stimulation simultaneously via multiple electrodes, to generate a percept that was composed of multiple phosphenes.

The monkeys first had to perform a simple behavioral task in which they made eye movements to report the location of a phosphene that was elicited during electrical stimulation via an individual electrode.

They were also tested on more complex tasks. The team found the monkeys successfully recognized shapes and percepts, including lines, moving dots, and letters, using their artificial vision.

The researchers say the new implant interfaces directly with the brain, bypassing prior stages of visual processing via the eye or the optic nerve.

Hence, in the future, such technology could be used for the restoration of low vision in blind people who have suffered injury or degeneration of the retina, eye, or optic nerve, but whose visual cortex remains intact.

One author of the study is Pieter Roelfsema.

The study is published in Science.

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