Category: Dyslexia

Diagnosing Dyslexia

The information in this blog is focused on developmental dyslexia, which is acquired through genetics.  Usually, students who acquire dyslexia through environmental causes can be flagged or diagnosed using the same information.

The definition of dyslexia is:

Dyslexia is a specific learning disability that is neurobiological 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 (International Dyslexia Association, 2002).

I am not big fan of labeling students for various reasons, but labeling must occur if the student is not getting the support and instruction that they need to acquire literacy skills.  Students will continue to struggle to acquire and use grade-level literacy skills, if they do not learn foundational literacy skills during their early elementary school days.  Most students can receive the support and instruction that they need to remain at grade-level through a response to intervention (RTI) or multitiered program.   RTI is a program that when implemented with fidelity can provide instructional lessons at student learning level, in addition to their regular classroom literacy instruction.  Some students will need more intense intervention that may include special education services, which requires the development of a 504 or IEP plan.  This will depend on your school’s literacy program and student learning needs.

Diagnosing dyslexia can be tricky and complex.  Dyslexia affects approximately 3 of every 20 students.  Dyslexia is blind to ethnicity and socioeconomic status.  Some students will “scream” dyslexia, many will not. Some students will never be diagnosed.  Children of parents diagnosed with developmental dyslexia have a 50% higher chance of having dyslexia.  It is also important to note that students can show traits of dyslexia, but not have developmental dyslexia.

Diagnosing dyslexia usually begins with a screening of student literacy skills.  A screening is a series of short probes or assessments used to learn student reading ability.   Most schools universally screen students three times a year.  Universal screenings can flag students who may have dyslexia, this will depend on the reading probes used to screen students.  Some probes have a stronger correlation to reading deficits normally found in individuals diagnosed with dyslexia.  Student knowledge of phonological awareness is a stronger flag until Grade 2, when rapid automatized naming tests (RAN) or reading fluency probes become a stronger flag (Ray, 2017).  Usually students that show a deficit in decoding nonsense words are dyslexic.  Teacher observations of student reading ability can strengthen the validity of a word decoding outcome.  There are also “private” on-line screenings.  Use on-line screening with caution, as not all screenings are valid.  The Shaywitz DyslexiaScreenTM was developed by Dr. Sally Shaywitz, a professor and researcher in Learning Development at Yale University. This screening can be used for students in kindergarten and Grade 1.  The screener can be found at https://dyslexia.yale.edu/, the Yale Center for Dyslexia and Creativity.  Students who show signs of literary deficits or traits of dyslexia may be assessed deeper or more extensively by a trained educational professional.

Diagnosing Dyslexia

The Gillingham (1955) formula of diagnosing dyslexia was developed by Anne Gillingham while she was working for Dr. Samuel Orton in the early 1900s.  She believed that standardized achievement tests were not a valid method to diagnose students’ reading deficits or to place students in remediation.  Gillingham determined that the following seven assessments should be given to students one year before beginning reading instruction: (a) intelligence, (b) optical or vision, (c) family history, (d) motor pattern or skills, (e) visual sensory recall skills, (f) auditory sensory recall skills, and (g) kinesthetic sensory skills.  The data from each assessment should be compiled and analyzed for each child.  The child is then placed into a classroom setting, based on the analyzed outcome of these assessment.  Gillingham noted that when students were assessed correctly and place in the proper programs, many of the emotional issues disappeared.  Gillingham also noted that occasionally the analyzed placement needed to be revisited as the child progressed through their formal education.  Gillingham (1956) believed that teachers in the regular classroom were the first to identify students at-risk for reading acquisition.

Today, dyslexia can be diagnosed by a neuropsychologist who specializes in educational disabilities, in particular dyslexia.  The process includes three or four hours of testing that can be quit tiring for students.  Most public schools do not have licensed psychologists trained to administer the depth of assessment required to diagnose dyslexia.  Students can also be diagnosed using MRI imaging.  This method of diagnosis should be used with caution, as very few people know how to conduct or correctly read the MRI screening images for dyslexia traits.

Ray, J.S. (2017).  Tier 2 interventions for students in grades 1-3 identified as at-risk in reading.  (Doctoral dissertation, Walden University).  Retrieved from https://scholarworks.waldenu.edu/dissertations/3826/

How the Brain Processes Written Language

Reading is not a natural activity; it is a learned process (Wolf, 2007).  The process of reading is very complex, using several highways and side-roads to effectively analyze written forms into usable information.  The process of learning how to read begins at birth when babies begin attaching sounds to meaning.  The brain also begins attaching visual or picture forms to sounds and meaning.  The natural foundation or wiring for reading is dependent on your genetics and its growth is dependent on your environment.

Most individuals are genetically wired to develop the basic or initial letter and word processing networks to analyze and convert written words into usable meaning.  The natural wiring includes three different regions of the brain that individuals use to process written words in meaning (Pugh et al. 2000; Eden, 2004).  These regions are located in the left hemisphere of the brain.  The first region is the anterior—interior front gyrus or Broca’s area of the brain (Pugh et al., 2000).  This region is responsible for processing articulatory recoding or phonological processing (Pugh et al., 2000; Moats, 2014).  This region connects letters to sounds.  The second region of the brain is the temporoparietal or Wernicke’s gyri (Pugh et al., 2000).  This area of the brain is known for processing orthography or visual representation into phonology or patterns of speech and semantic or meaning.  The third region that is necessary for fluid reading and meaning is the occipitotemporal or storage of familiar word forms (Pugh et al., 2000).  This area stores words, their pronunciations, and their meaning.  Some individuals do not have the natural wiring to learn how to read.

Individuals who have developmental dyslexia are not naturally wired to process written forms into speech and  meaning.  Researchers (Pugh, 2000; Eden, 2004; Hoeft, 2014) have learned through MRI imaging that individuals with developmental dyslexia initially only use the Anterior region of the brain or only one of the three regions necessary to effectively process written passages.  The other two regions are initially not connected to the Anterior region.  Dyslexics typically compensate using areas of the right side of the brain (Healy, 2010).  The connections can be developed through direct, systematic instruction.  Each individual student with dyslexia may need different types of intervention intensity to develop the necessary highways or bridges that connect the areas of brain that most individuals use to process written language.

 

References

International Dyslexia Association Conference (2013-2014) Dr. G. Eden, Dr. F. Hoeft, Dr. L. Moats, & Dr. K. Pugh

Healy, J. (2010). Different Learners. New York: Simon & Schuster

Wolf, M. (2007). Proust and the Squid. New York: Harper Perennial

What is Dyslexia?

Dyslexia has been woven in the fabric of society for centuries.  Dyslexia often goes unnoticed, as the severity or effects of dyslexia are different for each individual.  Some individuals are better at masking the effects than others.  This has made defining dyslexia a challenge.

In my research of dyslexia, I stumbled upon Dr. James Hinshelwood, an optical surgeon who worked at the Glasgow Eye Infirmary in Scotland during the 1890s through the early 1920s.  Some of his findings and definitions of word-blindness help to better understand the scope of the learning issue and why the definition has been hard to corral.

The following notes are from Hinshelwood’s (1917) research about individuals who struggle at learning how to read that were referred to the Glasgow Eye Infirmary or to an ophthalmologist for an examination.  As a result, Hinshelwood discovered that one student could not read more than two or three words by sight.  The student could only read if he or she was allowed to spell the words aloud one letter at a time or by moving his or her lips because the voiced word engaged the auditory memory, and the lip movement engaged speech or kinesthetic memory.  Hinshelwood also examined several students with similar problems.  For example, one student had healthy and normal vision, but he could not read any of the letters of the alphabet.  However, he could recite the alphabet by memory.  He could read a few words by spelling the words out letter by letter.  When he viewed the same word a few sentences later, he did not recognize the word.  The student had a good memory and excelled in his other subjects.  Hinshelwood’s work at the Glasgow Eye Infirmary led to the discovery of word-blindness.

Hinshelwood (1917) believed that congenital word-blindness was difficult to fully comprehend and was often misdiagnosed.  Hinshelwood noted that a German named Kussmaul determined that word blindness occurred when “complete text blindness may exist, although the power of sight, the intellect, and the powers of speech are intact” (p. 3).  Hinshelwood also noted that word-blindness meant “a condition in which with normal vision and therefore seeing the letters and words distinctly, an individual is no longer able to interpret written or printed language” (p. 4).  He believed that people could develop word-blindness as a result of family genetics or through injury.  Hinshelwood focused on the genetic causes of word-blindness, which led to the following definitions.

Hinshelwood (1917) defined three different degrees of congenital word-blindness: (a) congenital word-blindness, (b) congenital dyslexia, and (c) congenital alexia. He defined congenital word-blindness as the “pure and grave cases of defect” (Hinshelwood, 1917, p. 70).  Hinshelwood describes congenital dyslexia as a “slighter degrees of defect” (p. 70) or “great difficulty in interpreting written and printed symbols (Hinshelwood, 1900, p. 48).  Professor Berlin of Stuttgart introduced the term dyslexia to describe a group of patients struggling to learn how to read, “due to the development of cerebral disease” (p. 60).  Hinshelwood believed that congenital alexia was a defect in the visual memory center. The term congenital was noted to distinguish between natural and acquired.

Hinshelwood (1917) argued that each student diagnosed with word-blindness or dyslexia will have similar yet different characteristics and that diagnosis of students with word-blindness should begin in the regular education classroom.  Teachers in these classrooms should refer those students who are struggling with learning to read to an eye doctor for a visual examination.

After years of research that produce multiple definitions of dyslexia the International Dyslexia Association (IDA) developed a Definition Consensus Project or a committee to corral the definition of dyslexia.  On November 12, 2002, IDA adopted the following definition:

Dyslexia is a specific learning disability that is neurobiological 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.

After many years of research there are valid methods of diagnosing dyslexia, but it can still elude diagnosis.  I will discuss more about how to diagnose dyslexia in future posts.

 

References

Hinshelwood, James. (1900). Letter-, word- and mind-blindness. London: H. K. Lewis.

Hinshelwood, James. (1917). Congenital word-blindness.  London: H. K. Lewis.

Definition of Dyslexia (2002). International Dyslexia Association, Retrieved from:  https://dyslexiaida.org/definition-of-dyslexia/, July 11, 2018.

 

 

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