Sonar device brings vision to those blind from birth

Sonar device brings vision to those blind from birth

(NaturalNews) Researchers at Hebrew University in Jerusalem are
developing a sonar-based device that, according to preliminary tests,
already allows the congenitally blind to distinguish between different
shapes and even to read. Just as shockingly, the device appears to
activate areas of the brain that were formerly believed to be
permanently damaged in such people.

"These results suggest that
it may be possible, with the right technology and rehabilitation, to
'wake up' certain areas of the brain and access certain aspects of the
visual world, even after ... a lifetime of blindness," researcher
Laurent Cohen said.

The device was recently tested by a team of researchers from Hebrew University, the ICM Brain and Bone Marrow Institute Research Center, and NeuroSpin. The findings were published in the journal Neuron.

The
sonar device is specifically designed for people who have been blind
from birth. Known as a "sensory substitution device," it consists of a
small video camera mounted on a pair of glasses and connected to a
laptop or smart phone. The camera transmits information to the computer,
which then converts the visual images into specific sounds and relays
them to a set of headphones worn by the user. Each type of image
corresponds to a certain sound; for example, an oblique line would be
rendered as an increasingly high or low-pitched sound. This system
allows the device to convert even complex images into auditory packages.

The researchers found that after only 70 hours of training with the device, congenitally blind
users were able to correctly distinguish between different types of
images, such as faces versus houses. They were also able to correctly
identify people's locations and even read letters and words. The degree
of visual detail that users were able to perceive was such that a
sighted person who could see such detail would not be categorized as
blind by the World Health Organization.

Reactivating the visual cortex

The
researchers also used functional MRI scans to examine what occurred in
the brain during use of the device. They found that the areas of the
cerebral cortex associated with visual perception became highly active
when users listened to auditory representations of visual cues.

Scientists had previously assumed that these regions of the brain simply fail to develop in the congenitally blind.

It's not just the overall visual cortex that becomes active, either. In people with normal vision,
for example, a specific region of the visual cortex in the brain's left
hemisphere, known as the VWFA, becomes much more active when people
look at a string of letters than when they look at anything else. This
exact same differential response was seen in patients using the sensory
substitution device.

The findings support the hypothesis that
what the visual cortex actually does is analyze shapes, and that it can
perform this task based on any kind of sensory input.

"The fact
that this specialization for reading develops after just a few hours of
training shows a remarkable degree of cerebral plasticity," researcher
Stanislas Dehaene said.

Source:-
http://www.naturalnews.com/038151_blind_vision_sonar.html