Featured Research

from universities, journals, and other organizations

Activating the 'mind's eye': Alternative vision using sounds

Date:
November 7, 2012
Source:
Hebrew University of Jerusalem
Summary:
Common wisdom has it that if the visual cortex in the brain is deprived of visual information in early infanthood, it may never develop properly its functional specialization, making sight restoration later in life almost impossible. Scientists have now shown that blind people -- using specialized photographic and sound equipment -- can actually "see" and describe objects and even identify letters and words.

Illustration demonstrates the concept of visual-to-auditory sensory substitution. Images from a camera are converted into “soundscapes,” using a predictable algorithm, allowing the user wearing earphones to listen to and then interpret the visual information coming from the camera. This enables blind people to decode the visual information within the sounds and perceive complex images of people, words and objects.
Credit: Illustration by Karin Kedar and Michael Gluhoded

Common wisdom has it that if the visual cortex in the brain is deprived of visual information in early infanthood, it may never develop properly its functional specialization, making sight restoration later in life almost impossible.

Scientists at the Hebrew University of Jerusalem and in France have now shown that blind people -- using specialized photographic and sound equipment -- can actually "see" and describe objects and even identify letters and words.

The new study by a team of researchers, led by Prof. Amir Amedi of the Edmond and Lily Safra Center for Brain Sciences and the Institute for Medical Research Israel-Canada at the Hebrew University and Ph.D. candidate Ella Striem-Amit, has demonstrated how this achievement is possible through the use of a unique training paradigm, using sensory substitution devices (SSDs).

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 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. The blind participants using this device reach a level of visual acuity technically surpassing the world-agreed criterion of the World Health Organization (WHO) for blindness, as published in a previous study by the same group.

The resulting sight, though not conventional in that it does not involve activation of the ophthalmological system of the body, is no less visual in the sense that it actually activates the visual identification network in the brain.

The study shows that following a dedicated (but relatively brief) 70 hours of unique training paradigm developed in the Amedi lab, the blind people could easily use SSDs to characterize images into object categories, such as images of faces, houses, body shapes, everyday objects and textures. They could also identify even more complex everyday objects -- locating people's positions, identifying facial expressions, and even reading letters and words (for demos, movies and further information: http://brain.huji.ac.il/).

These unprecedented behavioral results are reported in the current issue of the neuroscience journal, Neuron.

The Hebrew University study went on further to actually test what happens in the brain when the blind learn to see with sounds. Specifically, the group tested the ability of this high-acuity vision to activate the supposedly dormant visual cortex of the blind, even though it was taught to process the visual images through sounds only in adulthood.

Prof. Amedi, and Ella Striem-Amit used functional magnetic resonance imaging (fMRI) to measure the neural activity of people blind from birth as they "saw" -- using the SSD -- high-resolution images of letters, faces, houses, everyday objects and body-shapes. Surprisingly, not only was their visual cortex activated by the sounds, their brain showed selectivity for visual categories which characterize the normally developing, sighted brain.

A specific part of the brain, known as the Visual Word Form Area, or VWFA -- that was first discovered in sighted people by Profs. Laurent Cohen and Stanislas Dehaene of Pitie-Salpιtriere Hospital-INSERM-CEA, of France, co-authors of the current article -- is normally very selective.

In sighted people, it has a role in reading, and is activated by seeing and reading letters more than by any other visual object category. Astonishingly, the same was found in this area in people deprived of sight. Their VWFA, after only tens of hours of training in SSD use, showed more activation for letters than for any of the other visual categories tested.

In fact, the VWFA was so plastic to change, that it showed increased activation for SSD letters after less than two hours of training by one of the study participants.

"The adult brain is more flexible that we thought," says Prof. Amedi. In fact, this and other recent research from various 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. (This information was summarized in a recent review by the Amedi research group published in the journal Current Directions in Neurology.)

All of this suggests that in the blind, brain areas might potentially be "awakened" to processing visual properties and tasks even after years or maybe even lifelong blindness, if the proper technologies and training approaches are used, says Amedi.

The findings also give hope that reintroduced input into the visual centers of the blind brain could potentially restore vision, and that SSDs might be useful for visual rehabilitation.

"SSDs might help blind or visually-impaired individuals learn to process complex images, as done in this study, or they might be used as sensory interpreters that provide high-resolution, supportive, synchronous input to a visual signal arriving from an external device such as bionic eyes" says Prof. Amedi.


Story Source:

The above story is based on materials provided by Hebrew University of Jerusalem. Note: Materials may be edited for content and length.


Journal Reference:

  1. Ella Striem-Amit, Laurent Cohen, Stanislas Dehaene, Amir Amedi. Reading with Sounds: Sensory Substitution Selectively Activates the Visual Word Form Area in the Blind. Neuron, 2012; 76 (3): 640 DOI: 10.1016/j.neuron.2012.08.026

Cite This Page:

Hebrew University of Jerusalem. "Activating the 'mind's eye': Alternative vision using sounds." ScienceDaily. ScienceDaily, 7 November 2012. <www.sciencedaily.com/releases/2012/11/121107122556.htm>.
Hebrew University of Jerusalem. (2012, November 7). Activating the 'mind's eye': Alternative vision using sounds. ScienceDaily. Retrieved August 27, 2014 from www.sciencedaily.com/releases/2012/11/121107122556.htm
Hebrew University of Jerusalem. "Activating the 'mind's eye': Alternative vision using sounds." ScienceDaily. www.sciencedaily.com/releases/2012/11/121107122556.htm (accessed August 27, 2014).

Share This




More Health & Medicine News

Wednesday, August 27, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

WHO Calls for Ban on E-Cigarette Sales to Minors

WHO Calls for Ban on E-Cigarette Sales to Minors

AFP (Aug. 26, 2014) — The World Health Organization called Tuesday on governments should ban the sale of e-cigarettes to minors, warning that they pose a "serious threat" to foetuses and young people. Duration: 01:44 Video provided by AFP
Powered by NewsLook.com
Have You Ever Been 'Sleep Drunk?' 1 in 7 Has

Have You Ever Been 'Sleep Drunk?' 1 in 7 Has

Newsy (Aug. 26, 2014) — A study published in the journal "Neurology" interviewed more than 19,000 people and found 15 percent suffer from being "sleep drunk." Video provided by Newsy
Powered by NewsLook.com
Does Medical Marijuana Reduce Painkiller Overdose Deaths?

Does Medical Marijuana Reduce Painkiller Overdose Deaths?

Newsy (Aug. 26, 2014) — A new study found fewer deaths from prescription drug overdoses in states that have legalized medical marijuana. But experts disagree on the results. Video provided by Newsy
Powered by NewsLook.com
Official: British Ebola Sufferer Receiving Experimental Drug

Official: British Ebola Sufferer Receiving Experimental Drug

AFP (Aug. 26, 2014) — A British nurse infected with Ebola while working in Sierra Leone is being given the same experimental drug used on two US missionaries who have recovered for the disease, doctors in London say. Duration: 00:44 Video provided by AFP
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
 
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:  

Breaking News:

More Coverage


Teaching the Blind to Read and Recognize Objects With Sounds

Nov. 7, 2012 — Areas of the brain in blind people can learn to process visual input through the use of sound, even after years or perhaps even lifelong blindness, according to new research. The findings challenge ... read more
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

    Environment News

    Technology News



    Save/Print:
    Share:  

    Free Subscriptions


    Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

    Get Social & Mobile


    Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

    Have Feedback?


    Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
    Mobile iPhone Android Web
    Follow Facebook Twitter Google+
    Subscribe RSS Feeds Email Newsletters
    Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins