By Gordon Sherman, Ph.D.
Neuroscientific tools, such as neuroimaging, promise to play a key role in the unfolding story of dyslexia - helping to clarify misconceptions, dispel controversy, and improve diagnosis and intervention.
Dyslexia results from a complex gene-environment interaction that begins in the womb and eventually modifies both the structure and function of the nervous system. This prompts the brain to develop according to a different blueprint. The result is a brain that does not process language in the usual way. Even with all we understand about this atypical development, mysteries remain.
Why do controversy and confusion often surround dyslexia? Partly because the work of the researchers, educators, and evaluators concerned with dyslexia often rests on inference - inferred assumptions about normal and atypical brain development and function.
Historically, to investigate the structure and neurophysiological function of brains, neuroscientists rely on the examination of brains obtained at autopsy or on studies of patients during neurosurgery. To understand learning and learning disabilities, clinicians and educators rely on closely observed behavior patterns. Scientists, clinicians, and educators study neural tissue or behaviors to infer what the brains of their patients, subjects, or students actually do in normal living and learning conditions.
Given the inexact nature of inference, many conclusions about dyslexia are subject to interpretation, and, thus, plagued by controversy. Since Pringle Morgan and James Hinshelwood first described dyslexia a little over 100 years ago, scientists, educators, and clinicians have debated dyslexia's definition, diagnosis, treatment, and even its existence.
Now, however, the brave new world of neuroimaging promises to put many dyslexia debates to rest. Much like the Hubble telescope enables us to see into remote corners of space, neuroimaging allows us to probe the frontiers of the human brain. As neuroimaging technology progresses, we will "see" the structure and functioning of living brains with increasing clarity - a scientific advancement beyond anything Morgan or Hinshelwood could have imagined.
Modern neuroimaging techniques, showing the activity of brain areas and networks, will help unravel the mysteries of dyslexia. While traditional neurological studies and clinical observations continue to provide valuable information, neuroimaging offers a window for viewing the structural and functional attributes of living and learning brains. Thus, neuroimaging promises to enhance the diagnosis of dyslexia, the design of educational programs, and the precision of prescriptive teaching.
Here is the most widely accepted definition of dyslexia:
Dyslexia is a specific learning disability that is neurological in origin. It is characterized by difficulties with accurate and/or fluent word recognition and by poor spelling and decoding abilities. These difficulties typically result from a deficit in the phonological component of language that is often unexpected in relation to other cognitive abilities and the provision of effective classroom instruction. Secondary consequences may include problems in reading comprehension and reduced reading experience that can impede growth of vocabulary and background knowledge. Adopted by the IDA Board, November 2002 and by the National Institutes of Health, 2002 .
Although this definition has proven useful, particularly for research purposes, it does not give us a concrete understanding of dyslexia.
Neuroimaging may lead us to a more precise definition of dyslexia, providing more specific information about its neurological basis and characteristics which, in turn, may yield additional diagnostic and educational insights.
Advanced neuroimaging tools also may aid in the diagnosis of dyslexia. Techniques such as PET (Positron Emission Tomography) and fMRI (Functional Magnetic Resonance Imaging) reveal the activity of the brain during tasks such as speaking, reading, and writing. If people with dyslexia show consistent and characteristic differences in brain function during such tasks, demonstrating a distinct "neurological profile," this information may lead to more precise identification and educational intervention.
Certainly, today's neuroimaging tools are too cumbersome and expensive, even too rudimentary, to be useful for common screening and diagnostic purposes. But who knows? Consider our remarkable evolution since Morgan and Hinshelwood. Technological advances making neuroimaging part of every child's kindergarten screening may be less science fiction than we might imagine.
Sign up for our newsletter and we'll send you more
insights to help you help your child succeed.
Thank you! You will begin to receive newsletters from us shortly.
Great work! Only one more step. Now we just need you to verify your email address. Please click on the link in the email we just sent you to complete your registration.
Great work! Only one more step. Now we just need you to verify your email address. Please click on the link in the email we just sent you to submit your review.
Please click on the link in the verification email we just sent you to complete your change of email address.
Whoops! It looks like we still need to verify your email. To do so, please click on the link in the email we sent you. Can't find the e-mail? Click the button below and we'll send you a new one.
Thanks for registering. Welcome to GreatSchools, the largest online community committed to improving educational outcomes through parental involvement.
Thanks for verifying your updated email address.
Oops! You haven't verified your email address yet. To do so, please click on the link in the email we sent you. Can't find the email? Click the button below to receive a new one.
Oops! That email verification link has expired. Please click the button below to receive a new one.
Create an account to submit your answers.
Sign in with an existing GreatSchools account or using Facebook:
Your review has been posted to GreatSchools.
Share with friends! Post your opinion of on Facebook.
Welcome to GreatSchools!
For principals and school officials, we offer a special Enhanced School Profile (ESP) which allows you to update and add information about your school, as well as respond to reviews. If you are a school official, click Continue to start.
Please note that it can take up to 48 hours for your comment to be posted to our site. While you're here, we'd like to invite you to fill out a survey on your school's programs, activities, and extracurriculars. It only takes a few minutes and will help parents get a full picture of your school.
Get started now! You have successfully registered and can now start updating your Official School Profile. The information you provide is extremely valuable in helping parents and students learn more about your school, so thanks for taking the time!
Thank you for registering as a school leader. We just need to verify your email address. We've sent you an email - please click on the link in that message to get started editing your school's information!
Thanks! We just sent you an email – please click on the link in the email to post your answers.
Get timely updates for , including performance data and recently posted user reviews.