Demystifying Dyslexia: Assessment, Evaluation, and Identification of Dyslexia
Now that I have defined dyslexia (see my previous blog post on 11/2/20), I am going to discuss how psychologists and neuropsychologist evaluate dyslexia.
Since dyslexia is a reading disability, the evaluation will include reading tests. How the individual performs on the reading test tells us simply what their reading ability is. However, if the individual’s performance is below average, the reading tests do not tell us why they are performing below average. In order to understand why and individual is struggling with reading, it is important for the evaluator to assess the individual’s cognitive functions. I am now going to review various cognitive processes that are important for reading.
The following cognitive processes are among the most important constructs pertaining to reading: phonological awareness, rapid automatized naming (RAN), verbal memory, retrieval fluency, visual spatial skills, and executive functions.
Phonological awareness refers to an individual’s ability to recognize and understand the sound structure of their oral language. That is words are comprised of phonemes, which are distinct sounds in a specified language that distinguish one word from other. For example, the sound /k/ as in cat has a distinct sound. That /k/ sound is in the words “cat,” “kit,” “scat,” and “skit,” despite using different graphemes (i.e., letter(s) used to identify a phoneme(s); the “c” in cat, “k” in kit, “sc” in scat, and “sk” in skit all have the same /k/ sound).
Poor phonological awareness skills are associated with poor reading, particularly decoding skills. However, by identifying weak phonemic awareness, once they are provided with interventions specifically to improve phonological awareness, their word reading skills improve.
Verbal (Phonological) Memory
Phonological memory refers to holding auditory information briefly in short-term memory. The part of memory that is responsible for this function is the phonological loop. Provided that an individual knows a particular word, phonological memory does not negatively impact decoding or listening; however, deficits in phonological memory can reduce an individual’s ability to learn new words. Evaluators will notice these deficits on measures of acquired knowledge.
Rapid Automatized Naming (RAN)
A cardinal deficit of an individual with an impairment in reading fluency is rapid automatized naming (RAN). Unlike the aforementioned phonological awareness and phonological memory terms, RAN has a visual component in addition to auditory component. When individuals have deficits in phonological awareness and RAN, they will have greater difficulty learning new words accurately and fluently than individuals with deficits in only one area.
Visual Spatial Skills
Successful readers and spellers have well developed phonological processing. They may find it easy to decode or sound out unfamiliar words. Then, they use visual memory or orthographic processing to retain the way words look in print so they can read fluently. They no longer have to rely on laboriously sounding out or decoding every word they read, but rather automatically recognize the words from previous exposure.
When individuals have difficulty visualizing letter-symbols, reading and spelling become extremely challenging, even when the student has strong phonological processing for letter sounds. For example, a student might be told that ‘though’ says /thoe/ but does not make a mental picture of this irregular orthographic pattern. As such, the student will have difficulty retaining this information over time and therefore will have to relearn it each time.
Some characteristics of an individual with weaknesses in visual spatial skills may include: difficulty with sight words, spelling how words sound rather than how they look (e.g., sighkowlogist for psychologist), guessing on simple words, reversing letters (b and d), sounding out every word.
Executive function is an umbrella term for the complex cognitive processes that underline flexible, goal-directed behavior. Some key executive functions that influence literacy include goal-setting, cognitive flexibility, organizing and prioritizing, working memory, and self-monitoring. Individuals with executive function deficits often experience frustration and failure. Of these concepts maybe the most obvious one for a struggling reader is one with self-monitoring deficits. This manifests as a reader that cannot recognize their errors and overly self-corrects, which manifests as dysfluent reading.
In addition to assessing these cognitive processes, the evaluator, of course, will want to directly assess the individual’s basic reading skills, oral and silent reading fluency, and reading comprehension.
Dr. Andersen’s Dyslexia Evaluations
When I (Dr. Brett Andersen) test individuals suspected of dyslexia, I thoroughly evaluate all of the aforementioned cognitive processes and reading skills. The majority of struggling readers that I encounter, regardless of age, dislikes reading because it is such a laborious task, and they know that they are not good at it. However, once I can understand their cognitive processes and know why reading is difficult, then I am able to identify a clear “roadmap” for improvement.
If you or your child is struggling with reading, please do not hesitate to contact me today for a comprehensive dyslexia evaluation.
I am excited to discuss various interventions, accommodations, and modification next time in my third blog post on demystifying dyslexia.