Unraveling the roots of dyslexia

March 12, 2009

By peering into the brains of people with dyslexia compared to normal readers, a study published online on March 12th in Current Biology, a Cell Press publication, has shed new light on the roots of the learning disability, which affects four to ten percent of the population. The findings support the notion that the reading and spelling deficit—characterized by an inability to break words down into the separate sounds that comprise them—stems in part from a failure to properly integrate letters with their speech sounds.

"The with in the study had enough reading experience to match letters and their correctly," said Vera Blau of the University of Maastricht, The Netherlands "Still, the results show that the way their brain integrates letters and speech sounds is very different from normal readers. It's quite astonishing."

The researchers examined activity in the brains of dyslexic and normal adult readers by using () as they were presented with letters, speech sounds, or a matching or non-matching combination of the two. While undergoing that task, dyslexic adults showed lower activation of a brain region known as the superior temporal cortex than the more typical readers did.

The findings point to a neural deficit in letter-speech sound integration as a fundamental mechanism that might distinguish poor from good readers, Blau said. Such a difficulty in integrating the most basic units of written and spoken language could offer a promising link between well-documented difficulties in processing the sounds of language (phonology) and the actual reading problem itself, she added.

Her team, led by Leo Blomert at the University of Maastricht, is currently conducting further studies in children as they are learning to read to help identify whether the difficulty to integrate letters with speech sounds begins in early school years and whether it comes before or after deficits in processing the sounds of language.

In addition to enhancing scientists' fundamental understanding of the disability, the new results might also have some ultimate implications for therapy.
"Our findings may offer a way to validate intervention strategies and narrow down the best training approaches," Blau said. Indeed, in a new series of studies, the group is investigating whether training strategies focused on phonological skills as well as letter-sound associations improve reading skills by changing activity levels in the brain of dyslexic readers.

Source: Cell Press (news : web)

Related Stories

Recommended for you

Drug found that induces apoptosis in myofibroblasts reducing fibrosis in scleroderma

December 15, 2017
(Medical Xpress)—An international team of researchers has found that the drug navitoclax can induce apoptosis (self-destruction) in myofibroblasts in mice, reducing the spread of fibrosis in scleroderma. In their paper ...

How defeating THOR could bring a hammer down on cancer

December 14, 2017
It turns out Thor, the Norse god of thunder and the Marvel superhero, has special powers when it comes to cancer too.

Researchers track muscle stem cell dynamics in response to injury and aging

December 14, 2017
A new study led by researchers at Sanford Burnham Prebys Medical Discovery Institute (SBP) describes the biology behind why muscle stem cells respond differently to aging or injury. The findings, published in Cell Stem Cell, ...

'Human chronobiome' study informs timing of drug delivery, precision medicine approaches

December 13, 2017
Symptoms and efficacy of medications—and indeed, many aspects of the human body itself—vary by time of day. Physicians tell patients to take their statins at bedtime because the related liver enzymes are more active during ...

Study confirms link between the number of older brothers and increased odds of being homosexual

December 12, 2017
Groundbreaking research led by a team from Brock University has further confirmed that sexual orientation for men is likely determined in the womb.

Potassium is critical to circadian rhythms in human red blood cells

December 12, 2017
An innovative new study from the University of Surrey and Cambridge's MRC Laboratory of Molecular Biology, published in the prestigious journal Nature Communications, has uncovered the secrets of the circadian rhythms in ...


Adjust slider to filter visible comments by rank

Display comments: newest first

not rated yet Mar 12, 2009
My husband and I are both dyslexic. I'm very high functioning, with the ability to read and write virtually unimpaired. I have great difficulty processing speech, and dealing with left/right motor confusion (I send the signal to the correct side, it ends up on the other.) I can read and write upside down, backwards, mirrored, etc., and made my living as a draftsman for a number of years, but have to really work to verbally give directions because I can "see" what I need to say, but can't say it. However, I can very easily give the same directions in writing - in fact, I made my living as a technical writer for years as well!

He is an excellent auditory learner, no problems processing speech whatsoever. His issue is visual when it comes to reading; he says the letters jump about on the page. He has no motor issues, left/right confusion, or difficulty giving directions.

If it was just a matter of difficulty in integrating letters with speech sounds, I *should not* be able to read and write effortlessly at a professional level, and my husband *should* !
not rated yet Mar 12, 2009
True but the study itself is a basic analysis at the regions of dyslexia. Even if you two can function relatively well under dyslexia, it means nothing if the roots aren't understood. Although your comment might show that there are different classes of dyslexia, and actions the brain does under it.

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.