Featured Research

from universities, journals, and other organizations

Dissecting dyslexia: Linking reading to voice recognition

Date:
July 30, 2011
Source:
National Science Foundation
Summary:
When people recognize voices, part of what helps make voice recognition accurate is noticing how people pronounce words differently. But individuals with dyslexia don't experience this familiar language advantage, say researchers.

When people recognize voices, part of what helps make voice recognition accurate is noticing how people pronounce words differently. But individuals with dyslexia don't experience this familiar language advantage, say researchers.

The likely reason: "phonological impairment."

Tyler Perrachione with the Massachusetts Institute of Technology explains, "Even though all people who speak a language use the same words, they say those words just a little bit differently from one another--what is called 'phonetics' in linguistics."

Phonetics is concerned with the physical properties of speech. Listeners are sensitive to phonetic differences as part of what makes a person's voice unique. But individuals with dyslexia have trouble recognizing these phonetic differences, whether a person is speaking a familiar language or a foreign one, Perrachione says.

As a Ph.D. candidate in Neuroscience at MIT, Perrachione recently examined the impacts of phonological impairment through experiments funded by the National Science Foundation's Directorate for Education and Human Resources.

He and colleague Stephanie Del Tufo as well as Perrachione's MIT research advisor John Gabrieli hypothesized that if voice recognition by human listeners relies on phonological knowledge, then listeners with dyslexia would be impaired when identifying voices speaking their native language as compared to listeners without dyslexia.

They also theorized that listeners with dyslexia hearing a foreign language would be no more impaired in voice recognition than listeners without dyslexia, because both groups would lack specific familiarity with how the foreign language was supposed to sound.

The journal Science reports their findings online July 29 in an article titled "Human voice recognition depends on language ability."

For their research study, the MIT scientists trained individuals with and without dyslexia to recognize the voices of people speaking either the listeners' native language of English or an unfamiliar foreign language, Mandarin Chinese. In each language, participants learned to associate five talkers' voices with unique cartoon avatars and were subsequently tested on their ability to correctly identify those voices.

The listeners were either typically-developing readers or individuals who experienced reading difficulties and dyslexia growing up.

The neuroscientists found individuals with dyslexia were significantly worse at being able to consistently recognize the voices of the English speakers. They were about the same as listeners without dyslexia at recognizing the Chinese voices; both groups were very poor at recognizing voices speaking an unfamiliar language.

"It is remarkable that individuals with dyslexia are no better able to identify voices speaking a familiar language than a foreign one," says Perrachione. "It is also very interesting that the reason for this is that they are less accurate at voice recognition than individuals who don't have dyslexia."

The result reaffirms the theory that the underlying deficit in dyslexia isn't about the act of reading per se, but instead involves difficulty with how sounds of spoken language are heard and processed in the dyslexic brain.

Contemporary theories of dyslexia often propose a "phonological deficit" as the reason some people struggle to translate written images into meaningful language. The idea is that individuals with dyslexia tend to do poorly on tests that ask them to decode words using conventional phonetic rules, thereby resulting in reading delays because of difficulties connecting language sounds to letters.

What theories of dyslexia have not been able to convincingly explain, say the researchers, is why there is no evident difficulty in the ability to perceive and produce speech among people with dyslexia. This is especially curious if the ability to recognize phonological sounds is impaired.

"Our results are the first to explicitly link impairment in reading ability to impairment in ecologically processing spoken language," says Perrachione. "The results suggest that the source of a phonological deficit might be in dyslexic individuals' difficulties learning the consistent properties of speech sounds as spoken by an individual talker."

Understanding these findings could help individuals with dyslexia in a variety of settings.

"Lots of research has shown that individuals with dyslexia have more trouble understanding speech when there is noise in the background," says Perrachione. "These results suggest that trouble following a specific voice might be part of the cause. Teachers and other educators can be sensitive to this during classroom instruction where noise from other classmates might make it disproportionately difficult for children with dyslexia to follow what is going on in a lesson."

Moreover, these findings suggest that individuals with dyslexia may find it difficult to notice consistent properties of speech sounds during learning. If further research verifies this trouble noticing consistency, it might suggest a specific direction for slowing or stopping early speech and language difficulties for young children at risk of dyslexia.


Story Source:

The above story is based on materials provided by National Science Foundation. Note: Materials may be edited for content and length.


Journal Reference:

  1. T. K. Perrachione, S. N. Del Tufo, J. D. E. Gabrieli. Human Voice Recognition Depends on Language Ability. Science, 2011; 333 (6042): 595 DOI: 10.1126/science.1207327

Cite This Page:

National Science Foundation. "Dissecting dyslexia: Linking reading to voice recognition." ScienceDaily. ScienceDaily, 30 July 2011. <www.sciencedaily.com/releases/2011/07/110729175548.htm>.
National Science Foundation. (2011, July 30). Dissecting dyslexia: Linking reading to voice recognition. ScienceDaily. Retrieved August 1, 2014 from www.sciencedaily.com/releases/2011/07/110729175548.htm
National Science Foundation. "Dissecting dyslexia: Linking reading to voice recognition." ScienceDaily. www.sciencedaily.com/releases/2011/07/110729175548.htm (accessed August 1, 2014).

Share This




More Mind & Brain News

Friday, August 1, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Work Can Be Stressful, But Is Unemployment Worse?

Work Can Be Stressful, But Is Unemployment Worse?

Newsy (Aug. 1, 2014) A new study shows stress at work can be hard on your health, but people who are unemployed might be at even greater risk of health problems. Video provided by Newsy
Powered by NewsLook.com
Google (Kind Of) Complies With 'Right To Be Forgotten Law'

Google (Kind Of) Complies With 'Right To Be Forgotten Law'

Newsy (July 31, 2014) Google says it is following Europe's new "Right To Be Forgotten Law," which eliminates user information upon request, but only to a certain degree. Video provided by Newsy
Powered by NewsLook.com
Stroke Signs: Three Hour Deadline

Stroke Signs: Three Hour Deadline

Ivanhoe (July 31, 2014) Sometimes the signs of a stroke are far from easy to recognize. Learn from one young father’s story on the signs of a stroke. Video provided by Ivanhoe
Powered by NewsLook.com
Grain Brain May Be Harming Us

Grain Brain May Be Harming Us

Ivanhoe (July 31, 2014) Could eating carbohydrates be harmful to our brain health? Find out what one neurologist says about changing our diets. Video provided by Ivanhoe
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:
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