How the brain learns to see !

If the eyes see again, the brain can readjust to see? It is not a trivial question: neuroscience have shown that the brain, when it is private long one of the senses, adapts to overcome the handicap reorganizing themselves, perhaps by allocating functions to other parties before dedicated to the

processing of signals coming from the direction interrupted.

Little is known about how this happens, and what happens when, perhaps after a long time, you retrieve the lost capacity due to treatment or prosthesis.

SECOND VIEW. A group of researchers at the University and the National Research Council in Pisa has tried to fill this gap in the case of view, studying some patients implanted with a prosthesis after years of almost total blindness. It is a call Second Sight technology, constituted by a camera that is mounted over eyeglasses, transmits images of the external world, processed and converted into electrical signals, to a microchip implanted on the patient's retina, which in turn stimulates the optic nerve .

The patient does not recover the view in a complete sense, but back to see shadows and contours, recovering some degree of autonomy. So far the system has been implanted on not more than 300 patients in the world. In Italy he imported the ophthalmic surgeon Stanislao Rizzo, University of Florence, who collaborated on the study.

BEFORE AND AFTER. The seven patients on which it was carried out the study (in English of PLOS Biology) were suffering from retinitis pigmentosa, a hereditary disease that gradually leads to vision loss. Their visual capacity was measured before and after implantation of the prosthesis and, in particular, the changes have been studied in their brain once with the prosthesis have begun to see.

Prior to surgery and then at a distance of about six months of implantation and again after, were made to patients of the monitored tests with magnetic resonance imaging, to study the activation of brain areas: were shown 15 seconds of darkness or a series of flash. While before the operation the area of the brain designed to process visual stimuli was totally turned off after the system is greatly activated, even with the prosthesis off.