One of the most frequent questions I am asked is, “Can you perform a dyslexia screening?” While I evaluate children, adolescents, and even adults for the presence of dyslexia, it is important to be clear on the definitions of both dyslexia and screening. Screening implies a brief assessment; however, dyslexia is a complex disorder comprised of ability and executive functioning deficits and any effective evaluation must test for each of these domains.
First, let’s define dyslexia. Dyslexia is a developmental disorder that is characterized by deficits in the cognitive processing areas of crystallized ability and auditory processing. These deficits are manifested by slow and labored reading, difficulty retaining letter-sound associations and decoding words, problems with spelling, trouble recognizing the shape and contours of letters and words, poor memory for and retrieval of learned words, low motivation for reading. Although some dyslexic individuals can understand what was read by using compensatory strategies like context clues, reading comprehension can be impacted because so much energy is devoted to decoding and storing words that processing is slowed and the main ideas are lost. Those individuals who have the added burden of a deficit in another ability area called fluid reasoning have more problems with comprehension because they do not have the capacity for higher order critical thinking. Executive functioning weaknesses manifested in dyslexia may include problems with verbal fluency (i.e. generating words), visual search and scan skills, short and long term memory, poor planning and organization (i.e. in written expression), and trouble with task completion.
Second, screening, according to Dr. Steven Feiffer, one of the leading authorities on dyslexia, recommends that screening should include testing for each of the deficit areas. He suggests a 90 minute screening that involves testing for: intelligence, phonemic awareness, rapid naming, verbal memory , reading fluency, orthographics, attention, executive functioning, and family history. It is important not to omit testing for any of these areas because there are different types of dyslexia. While many people think of dyslexia as a decoding problem (i.e. dysphonetic dyslexia), some individuals can effectively decode, but are unable to recognize by sight the way letters and words look (i.e. surface dyslexia). Moreover, others have both problems (i.e. mixed dyslexia).
Accurate assessment of the deficit areas is essential because instructional strategies must be targeted to these problems. That is, if an individual’s weakness is in orthographics, the visual recognition of letters and words, remediation that focuses on phonemic awareness will miss the mark. This is why screening should not be short sighted. It must touch on each of the above areas.