Study makes a speciality of restoring rudimentary form of vision in the blind – science



Restoration of vision in blind people through a mind implant is on the verge of turning into reality. Recent discoveries at the Netherlands Institute for Neuroscience (NIN) show that newly developed high-resolution implants in the visual cortex make it imaginable to recognise artificially induced shapes and percepts.

The findings were published in the publication Science.

The idea of stimulating the mind via an implant to generate man made visual percepts isn’t new and dates back to the 1970s. Alternatively, existing systems are only ready to generate a small number of man made ‘pixels’ at a time. At the NIN, researchers from a team led by Pieter Roelfsema are now the use of new implant production and implantation technologies, state of the art materials engineering, microchip fabrication, and microelectronics, to develop devices that are more steady and durable than preceding implants. The first results are very promising.

Electrical stimulation

When electrical stimulation is dropped at the mind via an implanted electrode, it generates the percept of a dot of light at a specific location in visual space, referred to 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 used to be to create interpretable images by delivering electrical stimulation concurrently via more than one electrodes, to generate a percept that used to be composed of more than one phosphenes. “The number of electrodes that we’ve got implanted in the visual cortex, and the number of man made pixels that we will be able to generate to produce high-resolution man made images, is unprecedented,” says Roelfsema.

Recognizing dots, lines and letters

The monkeys first had to perform a simple behavioural task in which they made eye movements to outline the location of a phosphene that used to be elicited right through electrical stimulation via an individual electrode. They were also tested on more complex tasks such as a direction-of-motion task, in which micro-stimulation used to be delivered on a sequence of electrodes, and a letter discrimination task, in which micro-stimulation used to be delivered on 8-15 electrodes concurrently, creating a percept in the form of a letter. The monkeys successfully recognized shapes and percepts, including lines, moving dots, and letters, the use of their man made vision.

“Our implant interfaces directly with the mind, bypassing prior stages of visual processing via the eye or the optic nerve. Hence, sooner or later, 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,” explains Xing Chen, a postdoctoral researcher in Roelfsema’s team.

This research lays the foundations for a neuroprosthetic device that could allow profoundly blind people to regain functional vision and to recognize objects, navigate in unfamiliar environment, and interact more easily in social settings, significantly bettering their independence and quality of life.

(This story has been published from a wire agency feed without modifications to the text.)

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