Brain Implants to Restore Vision

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"It's an absolutely stunning piece of work," says James Morrison, a physiologist and principal investigator for the Retinal Prosthesis Group at the University of Glasgow's Institute of Biomedical and Life Sciences, in Scotland. However, Morrison says, the position of the LGN is a major disadvantage of the approach. It's located in the middle of the head, making it difficult to access.

Recent advances in neurosurgical techniques, such as deep brain stimulators for treating Parkinson's disease, may help solve this issue: the LGN is just a few centimeters away from where these stimulators are placed, says Pezaris.

Still, it's too soon to say whether the findings will lead to better brain implants. "While I think the paper holds scientific merit, I think it will be extremely difficult to restore blindness from there," says Thomas Serre, a neuroscientist at the Center for Biological and Computational Learning at MIT's McGovern Institute for Brain Research. He believes that neurons in the LGN may be spaced too closely together to be stimulated individually, which would be important in trying to reproduce natural vision. "I don't think we will ever be able to go beyond generating very simple percepts like points of light," he says.

Pezaris accepts that a tremendous amount of work is needed before the LGN can be used to treat blindness, but he says this work does at least open the door to that possibility. "This was just the first very small step," he says.