Featured Research

from universities, journals, and other organizations

New Brain Findings On Dyslexic Children: Good Readers Learn From Repeating Auditory Signals, Poor Readers Do Not

Date:
November 12, 2009
Source:
Northwestern University
Summary:
The vast majority of school-aged children can focus on the voice of a teacher amid the cacophony of the typical classroom thanks to a brain that automatically focuses on relevant, predictable and repeating auditory information, according to new research. But for children with developmental dyslexia, the teacher's voice may get lost in the background noise of banging lockers, whispering children, playground screams and scraping chairs, the researchers say.

The vast majority of school-aged children can focus on the voice of a teacher amid the cacophony of the typical classroom thanks to a brain that automatically focuses on relevant, predictable and repeating auditory information, according to new research from Northwestern University.

Related Articles


But for children with developmental dyslexia, the teacher's voice may get lost in the background noise of banging lockers, whispering children, playground screams and scraping chairs, the researchers say. Their study appears in the Nov. 12 issue of Neuron.

Recent scientific studies suggest that children with developmental dyslexia -- a neurological disorder affecting reading and spelling skills in 5 to 10 percent of school aged children -- have difficulties separating relevant auditory information from competing noise.

The research from Northwestern University's Auditory Neuroscience Laboratory not only confirms those findings but presents biological evidence that children who report problems hearing speech in noise also suffer from a measurable neural impairment that adversely affects their ability to make use of regularities in the sound environment.

"The ability to sharpen or fine-tune repeating elements is crucial to hearing speech in noise because it allows for superior 'tagging' of voice pitch, an important cue in picking out a particular voice within background noise," said Nina Kraus, Hugh Knowles Professor of Communication Sciences and Neurobiology and director of the Auditory Neuroscience Laboratory.

In the article "Context-dependent encoding in the human auditory brainstem relates to hearing speech-in-noise: Implications for developmental dyslexia," Kraus and co-investigators Bharath Chandrasekaran, Jane Hornickel, Erika Skoe and Trent Nicol demonstrate that the remarkable ability of the brain to tune into relevant aspects in the soundscape is carried out by an adaptive auditory system that continuously changes its activity based on the demands of context.

Good and poor readers were asked to watch a video while the speech sound "da" was presented to them through an earphone in two different sessions during which the brain's response to these sounds was continuously measured.

In the first session, "da" was repeated over and over and over again (in what the researchers call a repetitive context). In the second, "da" was presented randomly amid other speech sounds (in what the researchers call a variable context). In an additional session, the researchers performed behavioral tests in which the children were asked to repeat sentences that were presented to them amid increasing degrees of noise.

"Even though the children's attention was focused on a movie, the auditory system of the good readers 'tuned in' to the repeatedly presented speech sound context and sharpened the sound's encoding. In contrast, poor readers did not show an improvement in encoding with repetition," said Chandrasekaran, lead author of the study. "We also found that children who had an adaptive auditory system performed better on the behavioral tests that required them to perceive speech in noisy backgrounds."

The study suggests that in addition to conventional reading and spelling based interventions, poor readers who have difficulties processing information in noisy backgrounds could benefit from the employment of relatively simple strategies, such as placing the child in front of the teacher or using wireless technologies to enhance the sound of a teacher's voice for an individual student.

Interestingly, the researchers found that dyslexic children showed enhanced brain activity in the variable condition. This may enable dyslexic children to represent their sensory environment in a broader and arguably more creative manner, although at the cost of the ability to exclude irrelevant signals (e.g. noise).

"The study brings us closer to understanding sensory processing in children who experience difficulty excluding irrelevant noise. It provides an objective index that can help in the assessment of children with reading problems," Kraus says.

For nearly two decades, Kraus has been trying to determine why some children with good hearing have difficulties learning to read and spell while others do not. Early in her work, because the deficits she was exploring related to the complex processes of reading and writing, Kraus studied how the cortex -- the part of the brain responsible for thinking --encoded sounds. She and her colleagues now understand that problems associated with the encoding of sound also can occur in lower perceptual structures.


Story Source:

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


Cite This Page:

Northwestern University. "New Brain Findings On Dyslexic Children: Good Readers Learn From Repeating Auditory Signals, Poor Readers Do Not." ScienceDaily. ScienceDaily, 12 November 2009. <www.sciencedaily.com/releases/2009/11/091111123600.htm>.
Northwestern University. (2009, November 12). New Brain Findings On Dyslexic Children: Good Readers Learn From Repeating Auditory Signals, Poor Readers Do Not. ScienceDaily. Retrieved January 27, 2015 from www.sciencedaily.com/releases/2009/11/091111123600.htm
Northwestern University. "New Brain Findings On Dyslexic Children: Good Readers Learn From Repeating Auditory Signals, Poor Readers Do Not." ScienceDaily. www.sciencedaily.com/releases/2009/11/091111123600.htm (accessed January 27, 2015).

Share This


More From ScienceDaily



More Mind & Brain News

Tuesday, January 27, 2015

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

How Technology Is Ruining Snow Days For Students

How Technology Is Ruining Snow Days For Students

Newsy (Jan. 25, 2015) More schools are using online classes to keep from losing time to snow days, but it only works if students have Internet access at home. Video provided by Newsy
Powered by NewsLook.com
Weird Things Couples Do When They Lose Their Phone

Weird Things Couples Do When They Lose Their Phone

BuzzFeed (Jan. 24, 2015) Did you back it up? Do you even know how to do that? Video provided by BuzzFeed
Powered by NewsLook.com
Smart Wristband to Shock Away Bad Habits

Smart Wristband to Shock Away Bad Habits

Reuters - Innovations Video Online (Jan. 23, 2015) A Boston start-up is developing a wristband they say will help users break bad habits by jolting them with an electric shock. Ben Gruber reports. Video provided by Reuters
Powered by NewsLook.com
Amazing Technology Allows Blind Mother to See Her Newborn Son

Amazing Technology Allows Blind Mother to See Her Newborn Son

RightThisMinute (Jan. 23, 2015) Not only is Kathy seeing her newborn son for the first time, but this is actually the first time she has ever seen a baby. Kathy and her sister, Yvonne, have been legally blind since childhood, but thanks to an amazing new technology, eSight glasses, which gives those who are legally blind the ability to see, she got the chance to see the birth of her son. It&apos;s an incredible moment and an even better story. Video provided by RightThisMinute
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:

Strange & Offbeat Stories


Health & Medicine

Mind & Brain

Living & Well

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