The characteristics of young and adult dyslexics readers on reading and reading related cognitive tasks as compared to normal readers.

Most of the research into dyslexia has been carried out among children and has raised the question whether the characteristics of young dyslexics are similar to those of adult dyslexics. The aim of this research was, therefore, to confirm whether the cognitive deficits, which appear among young dyslexics on reading and reading related tasks, are similar among adult dyslexics. Four groups of subjects were tested in this study: two groups of fourth graders, dyslexic and normal readers, and two groups of students, compensated dyslexics and normal readers. A comparison of the differences in research measures between the young dyslexics and their control group, and between the adult dyslexics and their control group, clearly indicates that the difference between regular readers and dyslexics is significantly smaller in the adult group on orthographic tasks, and this difference increases in adults on phonological tasks. The findings of this study reinforce the assumption that dyslexics have particular difficulty with the phonological-auditory channel. Another main finding is the slow speed of processing in verbal and non-verbal tasks. It can be assumed that these problems start at a young age and persist in compensated adult dyslexics.

[1]  Victor H. P. van Daal,et al.  Automatization Aspects of Dyslexia Speed Limitations in Word Identification, Sensitivity to Increasing Task Demands, and Orthographic Compensation , 1999 .

[2]  R. Edwards,et al.  The Wechsler Intelligence Scale for Children, 3rd Edition (Wisc-III) - Wechsler, D , 1993 .

[3]  Joseph K. Torgesen,et al.  Development of young readers' phonological processing abilities , 1993 .

[4]  Charles F. Levinthal,et al.  Orthographic and phonological coding during visual word matching as related to reading and spelling abilities in college students , 1992 .

[5]  Patricia Greig Bowers,et al.  Limits upon Orthographic Knowledge Due to Processes Indexed by Naming Speed , 1994 .

[6]  M. Bruck Persistence of dyslexics' phonological awareness deficits. , 1992 .

[7]  Joseph K. Torgesen,et al.  The Role of Orthographic Processing Skills on Five Different Reading Tasks. , 1992 .

[8]  Shlomo Bentin,et al.  Event-related potentials, semantic processes, and expectancy factors in word recognition , 1987, Brain and Language.

[9]  V. Mann,et al.  Reading disability: the role of language deficiencies. , 1988, Journal of consulting and clinical psychology.

[10]  H A Lubs,et al.  Spelling errors in adults with a form of familial dyslexia. , 1986, Child development.

[11]  A. van der Leij,et al.  Specific contributions of phonological abilities to early reading acquisition: Results from a Dutch latent variable longitudinal study , 1999 .

[12]  R. Reason,et al.  Dyslexia, Literacy and Psychological Assessment: a report of a working party of the British Psychological Society Division of Educational and Child Psychology , 1999 .

[13]  M. Wolf,et al.  The double-deficit hypothesis for the developmental dyslexias. , 1999 .

[14]  M W Lovett,et al.  A developmental approach to reading disability: accuracy and speed criteria of normal and deficient reading skill. , 1987, Child development.

[15]  S. Zecker,et al.  The orthographic code: Developmental trends in reading-disabled and normally-achieving children , 1991, Annals of dyslexia.

[16]  R. Wagner,et al.  The nature of phonological processing and its causal role in the acquisition of reading skills. , 1987 .

[17]  M. Bruck Word-Recognition Skills of Adults with Childhood Diagnoses of Dyslexia. , 1990 .

[18]  B. Pennington,et al.  Spelling errors and reading fluency in compensated adult dyslexics , 1991, Annals of dyslexia.

[19]  P. Wolff,et al.  The timing of syllable repetitions in developmental dyslexia. , 1990, Journal of speech and hearing research.

[20]  A. Fawcett,et al.  Towards the Origins of Dyslexia , 1993 .

[21]  J. Spruill A comparison of the Wechsler Adult Intelligence Scale—Revised with the Stanford-Binet Intelligence Scale (4th Edition) for mentally retarded adults. , 1991 .

[22]  Maggie Bruck,et al.  Persistence of dyslexics' phonological deficits. , 1992 .

[23]  H. Lubs,et al.  Nonsense passage reading as a diagnostic aid in the study of adult familial dyslexia , 1990 .

[24]  P. Bowers,et al.  Naming speed deficits in reading disability: multiple measures of a singular process. , 1991, Journal of experimental child psychology.

[25]  Mark S. Seidenberg,et al.  See Dick RAN: Rapid Naming and the Longitudinal Prediction of Reading Subskills in First and Second Graders , 1999 .

[26]  M. Bruck Outcomes of adults with childhood histories of dyslexia , 1998 .

[27]  Z. Breznitz Asynchrony of visual-orthographic and auditory-phonological word recognition processes: An underlying factor in dyslexia , 2002 .

[28]  Uta Frith,et al.  Phonological difficulties in high-functioning dyslexics , 1996 .

[29]  U. Frith,et al.  Explicit and implicit processing of words and pseudowords by adult developmental dyslexics: A search for Wernicke's Wortschatz? , 1999, Brain : a journal of neurology.

[30]  Marilyn Jager Adams,et al.  Beginning To Read: Thinking and Learning about Print. , 1991 .

[31]  F. Manis,et al.  Development of phonological and orthographic skill: a 2-year longitudinal study of dyslexic children. , 1993, Journal of experimental child psychology.

[32]  I. Lundberg,et al.  A Comparison of Components in Word Recognition between Dyslexic and Normal Readers. , 1995 .

[33]  F. Wood,et al.  Neuropsychological profile of adult dyslexics , 1990, Brain and Language.

[34]  Barbara R. Foorman,et al.  Phonological and Orthographic Processing: Separate but Equal? , 1994 .

[35]  F. Ramus,et al.  Theories of developmental dyslexia: insights from a multiple case study of dyslexic adults. , 2003, Brain : a journal of neurology.

[36]  H. Catts,et al.  Speech Production/Phonological Deficits in Reading-Disordered Children , 1986, Journal of learning disabilities.

[37]  M. Snowling,et al.  The Nonword Reading Deficit in Developmental Dyslexia: A Review. , 1992 .

[38]  J. Raven Advanced progressive matrices : sets I and II , 1962 .

[39]  Maryanne Wolf,et al.  Reading Fluency and Its Intervention , 2001 .

[40]  R. Klein,et al.  Auditory and Visual Temporal Processing in Dyslexic and Normal Readers , 1993, Annals of the New York Academy of Sciences.

[41]  A. V. Leij,et al.  Word processing in dyslexics , 1993 .

[42]  W. Lovegrove The Visual Deficit Hypothesis , 1992 .

[43]  R Hari,et al.  Auditory stream segregation in dyslexic adults. , 1999, Brain : a journal of neurology.

[44]  D. Francis,et al.  Persistence of dyslexia: the Connecticut Longitudinal Study at adolescence. , 1999, Pediatrics.

[45]  R. Salmelin,et al.  Dissociation of normal feature analysis and deficient processing of letter-strings in dyslexic adults. , 1999, Cerebral cortex.

[46]  P. Bowers Tracing symbol naming speed's unique contributions to reading disabilities over time , 1995 .

[47]  M. Snowling Phonological processing and developmental dyslexia , 1995 .