Human Brain Specialization Secrets Unlocked by Mapping the Brains of the Blind

Human brains can accomplish some amazing feats, and one of them is specialization. Now, scientists have studied the brain activity of blind individuals to learn a bit more about how the brain specializes to perform different kinds of tasks, shedding light on how our brains can adapt to technological changes.

The accepted view in previous years 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 are sub-regions that are specialized for specific tasks, such as the "visual word form area." This region of the brain is believed to identify words and letters from shape images even before they are associated with sounds or meanings.

Now, though, researchers may overturn this long-held view. They've used tools known as Sensory Substitution Devices (SSDs) to take information from one sense and present it in another. For example, blind people "see" by using other senses, such as touching or hearing. SSDs allow blind users to create mental images of objects, and even allow them to "read" letters by identifying their distinct soundscape.

In this case, the scientists wanted to see whether blind individuals using sensory substitution would use the visual-word-form-area sub-region of the brain to identify shape images. Using the SSDs, the individuals first identified objects by their sound. While the volunteers did so, scientists used functional MRI imaging (fMRI) to study their brain activity.

In the end, 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 being used.

"Beyond the implications for neuroscience theory, these results also offer us hope for visual rehabilitation," said Amir Amedi, one of the researchers, in a news release. "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 years of blindness."

The findings are published in the journal Nature Communications.

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