January 23, 2015: Studying the brain activity of blind people, scientists at the Hebrew University are challenging the standard view of how the human brain specializes to perform different kinds of tasks, and shedding new light on how our brains can adapt to the rapid cultural and technological changes of the 21st Century.
The accepted view in previous decades was that the brain is divided into distinct regions mainly by the sensory input that activates them, such as the visual cortex for sight and the auditory cortex for sound. Within these large regions, sub-regions have been defined which are specialized for specific tasks such as the “visual word form area,” a functional brain region believed to identify words and letters from shape images even before they are associated with sounds or meanings. Similarly there is another area that specializes in number symbols.
Now, a series of studies at the Hebrew University’s Amedi Lab for Brain and Multisensory Research challenges this view using unique tools known as Sensory Substitution Devices (SSDs).
Amedi’s team was interested in whether blind subjects using sensory substitution would, like sighted people, use the visual-word-form-area sub-region of the brain to identify shape images, or whether this area is specialized exclusively to visual reading with the eyes.
The researchers used functional MRI imaging (fMRI) to study the brains of blind subjects in real-time while they used an SSD to identify objects by their sound. They found that when it comes to recognizing letters, body postures and more, specialized brain areas are activated by the task at hand, rather than by the sense (vision or hearing) being used.
Their new findings suggest that unexpected brain connectivity can lead to rapid brain specialization, allowing humans to adapt to the rapid technological and cultural innovation of our generation. Vision, the researchers declared, is not a prerequisite for “visual” cortical regions to develop these preferences.
"Beyond the implications for neuroscience theory, these results also offer us hope for visual rehabilitation," says Amedi. "They suggest that by using the right technology, even non-invasively, we can re-awaken the visually deprived brain to process tasks considered visual, even after many years of blindness."
"If we take this one step further," adds Amedi, "this connectivity-based mechanism might explain how brain areas could have developed so quickly on an evolutionary timescale. We've only been reading and writing for several thousand years, but the connectivity between relevant areas allowed us to create unique new centers for these specialized tasks. This same 'cultural recycling' of brain circuits could also be true for how we will adapt to new technological and cultural innovations in the current era of rapid innovation, even approaching the potential of the Singularity."
The research was supported by a European Research Council grant; the Charitable Gatsby Foundation; the James S. McDonnell Foundation scholar award; the Israel Science Foundation; and the Edmond and Lily Safra Center for Brain Sciences (ELSC) Vision center grant.
About the Amedi Lab for Brain and Multisensory Research:
The Amedi Lab for Brain and Multisensory Research is headed by Prof. Amir Amedi in the Department of Medical Neurobiology at the Institute for Medical Research Israel-Canada (IMRIC) at the Hebrew University of Jerusalem’s Faculty of Medicine. The Lab is also a founding member of the Hebrew University’s Edmond & Lily Safra Center for Brain Science (ELSC).
The Lab deals with understanding the human brain, brain rehabilitation and plasticity, with emphasis on helping the blind and visually impaired. Several patented devices have been developed in the lab which can help people who are blind identify objects and navigate using a technique called "Sensory Substitution" (mainly 'seeing' by translating an image taken from a simple smartphone or webcam into sound with no need for special hardware).
For more information see: www.BrainVisionRehab.com (Go to 'Media Library' for Videos, Images and Documents)
TEDx talk at: http://www.youtube.com/watch?v=jVBp2nDmg7E
For more information see the Jerusalem Post.