High-Functioning Adult Dyslexics: Deficits and Compensatory Mechanisms
Most adults with a childhood diagnosis of dyslexia continue to experience significant reading and writing difficulties throughout their lives. These can include problems in identifying single words, comprehending written sentences, and spelling words correctly. Many of these adults have received remedial training as children and later participated in adult literacy programs, yet their problems persist, testifying to the significance of underlying cognitive deficits. Several studies, however, have also identified a group of adults with a childhood diagnosis of dyslexia whose adult reading is well within the normal range. This group has been termed “compensated dyslexics” by some researchers and “high-functioning” by others. It is estimated that 22 to 25 percent of children with dyslexia will eventually compensate for their initial reading acquisition difficulties and attend post-secondary education.
What “compensated” or “high-functioning” entails, however, is far from clear. A significant proportion of dyslexics who attend post-secondary education experience some academic difficulties and require accommodations in their studies. It seems that while these students have overcome their initial difficulties in learning to read, their victory is not complete. Several studies have indicated that they face persistent problems in manipulating phonemes accurately and rapidly, as in sounding out unfamiliar words. Such phonological processing and phonological recoding problems may, in turn, lead to slower word recognition, reduced reading comprehension efficiency, poor spelling, and problems in learning foreign languages.
High-functioning adult dyslexics are an important group to investigate for both theoretical and practical reasons. For example, definitions of dyslexia as a specific reading acquisition disorder cannot readily accommodate the performance pattern of compensated dyslexics. Most theoretical models of reading development cannot explain how high-functioning dyslexics have reached their reading level in spite of poor phonological skills. Understanding how compensation occurs and what is and is not compensated for can provide important information about the variability in adult reading strategies and in reading development. Similarly, how high-functioning dyslexics can be identified and what accommodations they should be allowed in their studies are significant practical and policy problems in many universities that cannot be solved without research-based evidence. Moreover, most high-functioning dyslexics are successful in their academic careers and their performance can provide important insights for designing effective reading instruction both for children with dyslexia and for those adult dyslexics who continue to experience significant reading problems.
Objectives of Our Research on High-Functioning Dyslexics
1. To determine how high-functioning adult dyslexics read.
2. To identify the reading-related cognitive processes that differentiate high-functioning adult dyslexics from normally-reading participants.
3. To determine if the various subtypes of developmental dyslexia can be reliably identified in this sample.
4. To identify the cognitive and socio-cognitive compensatory mechanisms that help high-functioning dyslexics succeed in higher education.
5. To generate research-based evidence that can be used to inform the design of remedial programs for children with dyslexia and for noncompensated adult dyslexics.
6. To determine how existing models of reading and reading development can accommodate the performance patterns of both compensated and noncompensated adult dyslexics.
University of Alberta
Social Sciences and Humanities Research Council of Canada
John Kirby, Queen's University
Lesly Wade-Woolley, Queen's University
Serge Hein, Virginia Tech
Robindra Sidhu, York University
Helene Deacon, Dalhousie University
Nenagh Kemp, University of Tasmania
Julie Corkett, Nipissing University
George Georgiou, University of Alberta
Deacon, S. H., Parrila, R., & Kirby, J. R. (in press). A review of evidence on morphological processing in dyslexics and poor readers. In A. Fawcett, F. Manis, G. Reid, & L. Siegel (eds.), Dyslexia Handbook. Sage Publications.
Kirby, J. R., Silvestri, R., Allingham, B., Parrila, R. & La Fave, C. (2008). Learning strategies and study approaches of college and university students with dyslexia. Journal of Learning Disabilities, 41, 85-96.
Parrila, R., Georgiou, G., & Corkett, J. (2007). University students with a significant history of reading difficulties: What is and is not compensated? Exceptionality Education Canada, 17, 195-220.
Corkett, J., Parrila, R., & Hein, S. (2007) Learning and study strategies of high-functioning developmental dyslexics in post-secondary education. Developmental Disabilities Bulletin, 34, 57-79.
Deacon, S. H. Parrila, R., & Kirby, J. R. (2006). Processing of derived forms in high-functioning dyslexics. Annals of Dyslexia, 56, 103-128.