Areas of the brain in blind people can learn to process visual input through the use of sound, even after years or perhaps even lifelong blindness, according to new research reported in the November issue of the Cell Press journal Neuron. The findings challenge the common belief that if the visual cortex of the brain is deprived of information in early life, it may never develop functional specialization.
"The adult brain is more flexible that we thought," says senior author Prof.. Amir Amedi, of the Edmond and Lily Safra Center for Brain Sciences and the Institute for Medical Research Israel-Canada at the Hebrew University Medical School.
In their studies, Prof. Amedi and his colleagues taught congenitally blind adults to use sensory substitution devices (SSDs), which are non-invasive sensory aids that provide visual information to the blind via their existing senses. For example, when a person uses a visual-to-auditory SSD, images from a video camera are converted into "soundscapes" that represent the images, allowing the user to listen to and then interpret the visual information coming from the camera (i.e. "seeing" with sounds).