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Appended is an article that appeared today in Wired Science, about research by Ella Striem-Amit and Amir Amedi of the Hebrew University of Jerusalem, using The vOICe. Best wishes, Peter Meijer Seeing with Sound - The vOICe http://www.seeingwithsound.com/winvoice.htm What happens in the brain when blind people learn to see with sound. By Greg Miller, March 6, 2014. Deprived of sight, blind people manage to squeeze an amazing amount ofinformation out of their other senses. Doing this requires their brains to do some reorganizing. To learn about some of these changes, scientists studied the brains of blind people who’ve learned to use an augmented reality system that
converts images into soundscapes.The system was invented in the early ’90s, but it’s not widely used. The way it works is a person puts on a pair of goggles with a built-in camera and software that converts images captured by the camera into sounds. For example, the pitch
of the sound (high or low) indicates the vertical position of an object; thetiming and duration of the sound indicate the object’s horizontal position and width (you can see and hear a demo of a similar technology here). For real world
scenes, the sounds are complex — in fact, they sound a bit like a garbled transmission from an alien spacecraft. But with enough practice people can learn to interpret the sounds and form a mental image of objects — including people — that appear in front of them.When sighted people see an outline or silhouette of a human body, areas of the cerebral cortex that specialize in making sense of visual stimuli become active.
One of these, the extrastriate body area, seems particularly interested in bodies: It responds more strongly to images of the human body than to other types of objects.But blindness cuts off the usual flow of information from the eyes to this part of the brain, and people who’ve been blind since birth have never actually seen a human form. Something must change in their brains when they learn to perceive
body shapes using sound. Do visual parts of the brain start responding tosounds? Or do auditory parts of the brain start responding to body shapes? It’s
a neat trick either way.To find out what really happens, Ella Striem-Amit and Amir Amedi of the Hebrew University of Jerusalem scanned the brains of seven congenitally blind people who’d trained for an average of 73 hours on the augmented reality system. After training, they achieved 78 percent accuracy at classifying three different types of objects: people, everyday objects (like a cellphone), or textured patterns.
In some cases, they could do even more. “During training, the participants were
asked to report the body posture of the people in the images they ‘saw,’ and could verbally describe it quite well, and also mimic it themselves,” Striem-Amit said.Functional MRI brain scans of the blind subjects and a group of sighted people showed that many of the same visual brain regions became active in both groups
when they perceived images of the human form. Even though the blind subjects weren’t actually seeing anything, their extrastriate body area fired up when they heard a soundscape corresponding to a person’s body. As in the sighted subjects, the responses in this area were specific — everyday objects andtextures didn’t elicit as much of a response, Striem-Amit and Amedi report today
in Current Biology.Striem-Amit and Amedi also found that in blind people as well as sighted people, body shapes also activated an area called the temporal-parietal junction, which some researchers think is involved in figuring out the intentions of other people.
The study illustrates that the brain can be remarkably malleable, says Kalanit Grill-Spector, a neuroscientist at Stanford University. When blind people learn
to read Braille, their visual cortex becomes sensitive to touch, she notes.“However, there has been little evidence for auditory stimuli driving responses in visual cortex in the blind,” Grill-Spector said. ”For example making human sounds such as clapping or laughing does not seem to activate visual cortex in
the blind.” (One exception is sounds of motion, such as footsteps, which cantrigger activity in a brain region that normally responds to the sight of moving
objects, but not to sounds).At the same time, the study also shows that some aspects of brain organization
remain stable, Grill-Spector says. The extrastriate body area, for example, appears to specialize in detecting human forms in sighted and blind people alike. It just uses different inputs to do it.Striem-Amit and Amendi acknowledge in their paper that this type of augmented
reality device has yet to be widely adopted by blind people. With someimprovements, they’re hoping it might be. Amendi’s lab has just released a a new free iPhone app called EyeMusic that adds new algorithms and different musical
instruments to provide information about color.Whether that’s enough to make the technology finally take off remains to be heard.
Source URL: http://www.wired.com/wiredscience/2014/03/blind-brain-sound/ ---------- To send a message to the list, send any message to blindza@xxxxxxxxxxxxx ---------- To unsubscribe from this list, send a message to blindza-request@xxxxxxxxxxxxx with 'unsubscribe' in the subject line --- The 'homepage' for this list is at http://www.blindza.co.za
