Leading-edge dyslexia research from Yale University’s Sally Shaywitz M.D.


Dr Sally Shaywitz M.D is a Professor in Learning Development and Co-director of the Yale Center for Dyslexia and Creativity at the Yale University Medical School. This page outlines all the key areas of her research referred to in this 4D Edge webspace. For more information, visit Dr Shaywitz’s knol – Dyslexia: The science of reading and dyslexia.

fMRI Brain mapping
The Yale Center for Dyslexia and Creativity laboratory was one of first to image the dyslexic brain using functional magnetic resonance imaging (fMRI). The laboratory has now imaged several thousand children and adults as they read. fMRI is similar to MRI (often used to investigate headaches or bone injuries), but uses more sophisticated hardware and software that allows it to capture brain changes – mainly blood flow – as a person performs a specific cognitive task, for example reading. This technology has revolutionized understanding of reading and dyslexia. 


Generally, the left brain controls linguistic functioning, and the right brain controls visual processing. Dr Shaywitz’s research shows these aspects may be disrupted or located differently in the dyslexic brain. Her analysis of data, using fMRI from around the world, indicates three neural systems used for reading, all in the left side of brain. In the dyslexic brain, disruption was observed in the two neural systems in the back of the brain. Thus a ‘neural signature’ for dyslexia has been observed.

Imaging also reveals compensatory overactivation in other parts of the reading system. The compensatory neural systems allow a dyslexic person to read more accurately. However, the critical visual word-form area remains disrupted and difficulties with rapid, fluent, automatic reading persist. The dyslexic continues to read slowly. In addition, neurobiological evidence is beginning to emerge indicating that many dyslexics are not able to make good use of sound-symbol linkages as they mature, and instead, they come to rely on memorized words.

A recent fMRI study also demonstrates the importance of memory systems in dyslexic readers. Together, these recent neurobiological findings suggest that as dyslexic children mature, neural systems supporting word memorization develop, rather than the systems supporting sound-symbol linkages and automatic reading that are observed in typical readers.

Functional imaging has been helpful in demonstrating that the neural systems for reading are malleable, and that the disruption in these systems in young struggling readers can be modified by an effective reading intervention. Compared to struggling readers who received other types of intervention, children who received an evidence-based application of the alphabetic principle not only improved their reading but, compared to pre-intervention brain imaging, demonstrated increased activation in the neural systems for reading. This data has important implications in teaching children to read: the provision of an evidence-based reading intervention at an early age improves reading and facilitates the development of those neural systems necessary for reading.

Defining dyslexia
Dr Shaywitz describes dyslexia as: “…an unexpected difficulty in reading. Unexpected refers to children and adults who appear to have all the factors necessary to become good readers: intelligence, motivation and exposure to reasonable reading instruction – and yet struggle to read."

Population incidence of dyslexia
Research by Sally Shaywitz discovered through MRI scans and associated research (including a longitudinal study started in 1983) that 16-22% of the population are dyslexic. However, only 10% are generally identified in school as those that are of high intelligence or with favourable circumstances are able to compensate and hit the academic benchmarks.

She also notes that dyslexia affects just about as many girls as boys. It is used to be thought that dyslexia affected primarily boys, and as a result, mainly boys were identified; girls who were sitting quietly at their desks – and not reading – tended to be overlooked. This reflects what is referred to as selection bias, with teachers tending to refer for further evaluation boys who were more active and impulsive. In contrast, girls - who were not learning to read, but who were perceived as behaving more “properly” - were not identified by their schools as having a reading problem. 

Strengths in higher level thinking processes
Research by Dr Sally Shaywitz has found that dyslexics often display a range of strengths in higher level thinking processes.

Strengths in higher level thinking processes include:

  • High learning capability

  • Noticeable improvement when given additional time on multiple choice tests

  • Noticeable excellence when focused on a highly specialized area such as medicine, law, public policy, finance, architecture, basic science

  • Excellence at writing if content and not spelling is important

  • Noticeable articulateness in expression of ideas and feelings

  • Exceptional empathy and warmth and feeling for others

  • Success in areas not dependent on rote memory

  • Talent for high level conceptualization

  • Ability to come up with original insights

  • Big picture thinkers

  • Inclination to think out-of-the-box

  • Noticeable resilience and ability to adapt

Reflecting these strengths, dyslexics are often high level conceptualizers who manifest “out-of-the-box thinking” and are frequently the ones who provide new insights. As a person who is dyslexic progresses and is able to specialize in an area, s/he may become relatively automatic in reading the vocabulary recurring in that area.

Dyslexics are often represented at the higher levels of a range of professions and are frequently found as leaders in such diverse areas as science, medicine, law, business, writing/literature, poetry.

The importance of, and scientific basis for, accommodations
According to Sally Shaywitz, disparity between reading and intellectual abilities of dyslexics means accommodations are critical to assure fairness and equity. Dr Shaywitz’s was one of the first laboratories to image the dyslexic brain using functional magnetic resonance imaging (fMRI). They have imaged several thousand children and adults as they read. Their findings, combined fMRI data from around the world, show that three neural systems are used for reading, all in the left side of brain. Dyslexics, however, have a neural signature of disruption of two neural systems in the back of the brain.

Many dyslexics are not able to make good use of sound-symbol linkages and rely on memorised words instead. Often it is not a matter of not knowing the answer, rather the problem is in pulling the word out and saying it. In short, it is not that they don’t know, but that they have trouble retrieving and accessing information. Therefore accommodations of time in the classroom, for example, have a neurobiological basis and help level the playing field.

Dr Shaywitz says a major advance has been the convergence of behavioral and neuroimaging data providing evidence for this critical need for extra-time on examinations for dyslexic students, particularly as they progress towards high school graduation and beyond. Thus, behavioral data indicating the persistence of dysfluent reading are now supported by neurobiological data. In terms of the neural signature for dyslexia, the posterior reading systems, especially the left occipto-temporal (word-form) region responsible for fluent, rapid reading, is disrupted in dyslexic children and adults.

Other compensatory systems, in the frontal regions on both left and right hemispheres, and the right hemisphere homologue of the word form area develop, and these systems support increased accuracy over time. However, the word-form region does not develop and compensatory pathways do not provide fluent or automatic reading. Accordingly, if such students are to demonstrate the full range of their knowledge, providing additional time on examinations is a necessity to compensate for the lack of availability of the efficient word-form area and to level the playing field.

Dr Shaywitz identifies three general types of accommodations.

  • Those that bypass the reading difficulty by providing information through an auditory mode

  • Those that provide compensatory assistive technologies, and

  • Those that provide additional time so that the dysfluent reader can demonstrate his/her knowledge

According to Dr Shaywitz, contemporary management of dyslexia provides evidence-based accommodations including: access to recorded materials; computers and print-to-speech software; additional time on examinations, with amount of time determined by the student’s experience. In addition, it is inappropriate to assess a dyslexic person’s knowledge based on his/her performance on an oral examination in which that individual is under pressure to provide a quick or glib response.

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