Turning Images Into Sensations to Assist the Blind

Years ago, scientists began to learn that certain parts of the brain had certain duties. For example, one part was responsible for breathing; another dealt with the sense of smell. Scientists thought our brains could not change. But then they discovered that the brain could sometimes reorganize itself when conditions required. Josef Rauschecker is a professor of physiology and biophysics at Georgetown University in Washington. He wondered if this ability to change could explain the idea that other senses in blind people improve to balance their lack of vision.He noted the large number of blind musicians including Ray Charles, Stevie Wonder, and Andrea Bocelli.The visual cortex is the part of the brain that processes sight. But earlier research by Professor Rauschecker and other scientists found that it can also do other jobs. The research showed that the brains of blind people can use the visual cortex to process sound and touch. But the visual cortex is divided into separate parts, or modules. Each module normally performs different jobs related to vision. Professor Rauschecker said: “Do blind people have that same or similar functional organization, that these modules just get rededicated to touch and hearing? And the answer is yes.”Professor Rauschecker and researchers from Finland and Belgium found this answer using an fMRI scanner. That means functional magnetic resonance imaging. The machine recorded brain activity as twelve blind people and twelve sighted people performed tasks involving sound and touch. For example, they would try to decide which direction sounds were coming from, or which finger was feeling gentle vibrations. Professor Rauschecker says large parts of the visual cortex became active during the sound and touch tests, but only in the blind people. He says this study and earlier research has led to an experimental device designed to help the blind. It can process images taken by a camera into sensations that could be used by a blind person wearing it. He said the device would change visual information into auditory information that could be processed by the brain of a blind person. The study is in the journal Neuron. For VOA Special English I’m Alex Villarreal.