Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Sound rather than sight can activate ‘seeing’ for the blind

07.02.2012
Scientists at the Hebrew University of Jerusalem have tapped onto the visual cortex of the congenitally blind by using sensory substitution devices (SSDs), enabling the blind in effect to “see” and even describe objects.

SSDs are non-invasive sensory aids that provide visual information to the blind via their existing senses. For example, using a visual-to-auditory SSD in a clinical or everyday setting, users wear a miniature video camera connected to a small computer (or smart phone) and stereo headphones.

The images are converted into “soundscapes,” using a predictable algorithm, allowing the user to listen to and then interpret the visual information coming from the camera.

Remarkably, proficient users who have had a dedicated (but relatively brief) training as part of a research protocol in he laboratory of Dr. Amir Amedi, of the Edmond and Lily Safra Center for Brain Sciences and the Institute for Medical Research Israel-Canada at the Hebrew University, are able to use SSDs to identify complex everyday objects, locate people and their postures, and read letters and words.

In addition to SSDs’ clinical opportunities, using functional magnetic resonance imaging opens a unique window for studying the organization of the visual cortex without visual experience by studying the brain of congenitally blind individuals.

The results of the study in Amedi’s lab, recently published in the journal Cerebral Cortex, are surprising. Not only can the sounds, which represent vision, activate the visual cortex of people who have never seen before, but they do so in a way organized according to the large-scale organization and segregation of the two visual processing streams.

For the past three decades, it has been known that visual processing is carried out in two parallel pathways. The ventral occipito-temporal “what” pathway, or the “ventral stream,” has been linked with visual processing of form, object identity and color. Its counterpart is considered to be the dorsal occipito-parietal “where/how” pathway, or the “dorsal stream,” which analyzes visuo-spatial information about object location and participates in visuo-motor planning.

Although this double dissociation between the processing of the two streams has been thoroughly validated, what remained unclear was the role of visual experience in shaping this functional architecture of the brain. Does this fundamental large-scale organizational principle depend on visual experience?

Using sensory substitution, the Hebrew University scientists, led by Ph.D. student Ella Striem-Amit and Dr. Amedi, discovered that the visual cortex of the blind shows a similar dorsal/ventral visual pathway division-of-labor when perceiving sounds that convey the relevant visual information; e.g., when the blind are requested to identify either the location or the shape of an SSD “image,” they activate an area in the dorsal or in the ventral streams, respectively.

This shows that the most important large-scale organization of the visual system into the two streams can develop at least to some extent even without any visual experience, suggesting instead that this division-of-labor is not at all visual in its nature.

Recent research from Amedi’s lab and from other research groups have demonstrated that multiple brain areas are not specific to their input sense (vision, audition or touch), but rather to the task or computation they perform, which may be computed with various modalities.

Extending these finding to a large-scale division-of-labor of the visual system further contributes crucial information towards postulating that the whole brain may be task-specific rather than dependent on a specific sensory input. "The brain is not a sensory machine, although it often looks like one; it is a task machine," summed up Amedi.

These findings suggest that the blind brain can potentially be “awakened” to processing visual properties and tasks, even after lifelong blindness, with the aid of visual rehabilitation, using future medical advances, such as retinal prostheses, say the researchers. A summary of these ideas were published recently in a review in Current Opinion in Neurology by Lior Reich and Shachar Maidenbaum from Amedi’s lab.

A photo of Dr. Amedi wearing one of the SSD devices developed as the result of research in his lab is available at:.

http://media.huji.ac.il/new/photos/hu120207_sightfromsound.jpg

CONTACT:

Jerry Barach, Hebrew University Foreign Press Liaison
02-5882904 (international: 972-2-5882904)
dovs@savion.huji.ac.il
Orit Sulitzeanu, Hebrew University Spokesperson
02-5882910, mobile: 054-882-0016
orits@savion.huji.ac.il

Jerry Barach | Hebrew University of Jerusalem
Further information:
http://www.huji.ac.il

More articles from Health and Medicine:

nachricht Millions through license revenues
27.04.2017 | Rheinische Friedrich-Wilhelms-Universität Bonn

nachricht New High-Performance Center Translational Medical Engineering
26.04.2017 | Fraunhofer ITEM

All articles from Health and Medicine >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Making lightweight construction suitable for series production

More and more automobile companies are focusing on body parts made of carbon fiber reinforced plastics (CFRP). However, manufacturing and repair costs must be further reduced in order to make CFRP more economical in use. Together with the Volkswagen AG and five other partners in the project HolQueSt 3D, the Laser Zentrum Hannover e.V. (LZH) has developed laser processes for the automatic trimming, drilling and repair of three-dimensional components.

Automated manufacturing processes are the basis for ultimately establishing the series production of CFRP components. In the project HolQueSt 3D, the LZH has...

Im Focus: Wonder material? Novel nanotube structure strengthens thin films for flexible electronics

Reflecting the structure of composites found in nature and the ancient world, researchers at the University of Illinois at Urbana-Champaign have synthesized thin carbon nanotube (CNT) textiles that exhibit both high electrical conductivity and a level of toughness that is about fifty times higher than copper films, currently used in electronics.

"The structural robustness of thin metal films has significant importance for the reliable operation of smart skin and flexible electronics including...

Im Focus: Deep inside Galaxy M87

The nearby, giant radio galaxy M87 hosts a supermassive black hole (BH) and is well-known for its bright jet dominating the spectrum over ten orders of magnitude in frequency. Due to its proximity, jet prominence, and the large black hole mass, M87 is the best laboratory for investigating the formation, acceleration, and collimation of relativistic jets. A research team led by Silke Britzen from the Max Planck Institute for Radio Astronomy in Bonn, Germany, has found strong indication for turbulent processes connecting the accretion disk and the jet of that galaxy providing insights into the longstanding problem of the origin of astrophysical jets.

Supermassive black holes form some of the most enigmatic phenomena in astrophysics. Their enormous energy output is supposed to be generated by the...

Im Focus: A Quantum Low Pass for Photons

Physicists in Garching observe novel quantum effect that limits the number of emitted photons.

The probability to find a certain number of photons inside a laser pulse usually corresponds to a classical distribution of independent events, the so-called...

Im Focus: Microprocessors based on a layer of just three atoms

Microprocessors based on atomically thin materials hold the promise of the evolution of traditional processors as well as new applications in the field of flexible electronics. Now, a TU Wien research team led by Thomas Müller has made a breakthrough in this field as part of an ongoing research project.

Two-dimensional materials, or 2D materials for short, are extremely versatile, although – or often more precisely because – they are made up of just one or a...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Fighting drug resistant tuberculosis – InfectoGnostics meets MYCO-NET² partners in Peru

28.04.2017 | Event News

Expert meeting “Health Business Connect” will connect international medical technology companies

20.04.2017 | Event News

Wenn der Computer das Gehirn austrickst

18.04.2017 | Event News

 
Latest News

Wireless power can drive tiny electronic devices in the GI tract

28.04.2017 | Medical Engineering

Ice cave in Transylvania yields window into region's past

28.04.2017 | Earth Sciences

Nose2Brain – Better Therapy for Multiple Sclerosis

28.04.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>