Evaluating normal children and those with learning problems using the Adult Dyslexic Test, Dyslexic Determination Test, Peabody Picture Vocabulary Test, Test of Auditory Analysis Skills, and Irlen Screening Test
Date of Award
Master of Science in Vision Science
Robert L. Yolton
Hannu Laukkanen, OD MEd
Introduction: There has been a great deal of speculation over the years as to what causes reading problems. lrlen has suggested that a condition called Scotopic Sensitivity Syndrome is at fault in many cases. Others believe that a neurological problem called dyslexia (word blindness) is responsible for severe reading problems. Even though experts have been unable to agree on precisely what SSS dyslexia is, screening tests have become standardized and accepted as valid means of diagnosis. The tests have also become an acceptable means of classifying the type of dyslexia that a person may have. The goal of our study was to use standardized testing for dyslexia and compare the results with lrlen testing to determine if there is a significant relationship between dyslexia and Scotopic Sensitivity Syndrome.
Subjects: The subject population consisted of 29 individuals (22 males ranging in age from 8 to 27, and seven females ranging from the age of 8 to 39). Their grade levels ranged from the third grade through graduate level with the majority of the students being in the seventh grade.
Tests Used: The Test of Auditory Analysis Skills (TAAS) is a simple auditory perception test. The Peabody Picture Vocabulary Test (PPVT) is a quick screening test of the subject's level of intelligence. It was administered to rule out any reading disabilities that may be associated with below average intelligence. The Dyslexia Determination Test (DDT) is to identify individuals up to age 17 who exhibit dyslexia. The lrlen Differential Perceptual Schedule (lOPS) is comprised of various symbols and shapes such as cubes, pumpkins, and closely spaced figures that are designed to elicit symptoms of Scotopic Sensitivity Syndrome.
Results: There was no statistical relationship between SSS and dyseidetic classifications. There was a statistical relationship between SSS and dysphonesia, however it was determined to not be a meaningful relationship.
Discussion: Levels of dyseidetic and dysphonetic dyslexia were compared to SSS levels. The lack of an association between dyslexia and SSS, and the fact that higher SSS classifications do not correspond to higher dyslexia readings in our test group, suggest that SSS and dyslexia are separate conditions.
Johnson, Jodie J. and Woodmansee, James A., "Evaluating normal children and those with learning problems using the Adult Dyslexic Test, Dyslexic Determination Test, Peabody Picture Vocabulary Test, Test of Auditory Analysis Skills, and Irlen Screening Test" (1996). College of Optometry. 1149.