Navigation Links
Dissecting dyslexia: Linking reading to voice recognition
Date:7/29/2011

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 today 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.


'/>"/>

Contact: Bobbie Mixon
bmixon@nsf.gov
703-292-8485
National Science Foundation
Source:Eurekalert

Related medicine news :

1. Doctor Behind Study Linking Vaccine to Autism Accused of Deliberate Fraud
2. Investigational eye treatment: Corneal collagen crosslinking research study
3. Experts explore emerging evidence linking diabetes and cancer
4. Blinking neurons give thoughts away
5. Researchers find further evidence linking Epstein-Barr virus and risk of multiple sclerosis
6. New clues found linking larger animals to colder climates
7. San Diego State University and BIOCOM Institute Receive $4.95 Million Grant: The BRIDGE Project, Linking Education to Employment in San Diegos Life Sciences Industry
8. MSU researcher linking breast cancer patients with alternative therapies
9. Dogs Adept at Reading Peoples Minds
10. At-Home Blood Pressure Monitoring More Telling Than Doctors Office Readings
11. Single Reading Cant Gauge Blood Pressure Control: Study
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:10/13/2017)... , ... October 13, 2017 , ... Apple Rehab ... services, staged a mock evacuation of the facility as part of a disaster drill ... Department, Echo Hose EMS and Shelton City Emergency Manager, as well as the ...
(Date:10/13/2017)... (PRWEB) , ... October 13, 2017 , ... Ellevate Network, ... in business to advocate for action towards gender equality at their inaugural Summit in ... around the globe, and reached a social audience of over 3 million. To watch ...
(Date:10/13/2017)... ... October 13, 2017 , ... Talented host, ... lowdown on sciatica in a new episode of "Success Files," which is an ... and innovation and investigates each subject in-depth with passion and integrity. , Sciatica ...
(Date:10/13/2017)... ... October 13, 2017 , ... “America On The Brink”: the ... “America On The Brink” is the creation of published author, William Nowers. Captain ... As a WWII veteran, he spent thirty years in the Navy. Following his ...
(Date:10/12/2017)... ... October 12, 2017 , ... Planet Fitness, one of the largest and ... plans to open a flagship location in Covington, LA at 401 N. U.S. Highway ... store next to Office Depot in the Holiday Square shopping center. Its location allows ...
Breaking Medicine News(10 mins):
(Date:9/27/2017)... -- Commended for their devotion to personalized service, SMP Pharmacy Solutions ... in the South Florida Business Journal,s 50 Fastest-Growing Companies, and ... the national specialty pharmacy has found its niche.  To that ... be honored by SFBJ as the 2017 Power Leader in ... receive his award in October, Bardisa said of the three ...
(Date:9/25/2017)...  EpiVax, Inc., a leader in the fields ... announced the launch of EpiVax Oncology Inc., a ... cancer vaccines. EpiVax has provided $500,000 in seed ... technologies to the new precision immunotherapy venture. Gad ... as Chief Executive Officer. Gad brings over 25 ...
(Date:9/22/2017)... -- AVACEN Medical (AVACEN) announced that its CE-Marked AVACEN ... with the widespread pain associated with fibromyalgia in the ... Essex, England commented, "I had difficulty ... sleep at all, tremendous pain, with every movement sending ... AVACEN 100] enough, how this has and is helping ...
Breaking Medicine Technology: