Reading disability subtypes and the test of memory and learning

For Study 1, 24 readers with dysphonetic dyslexia and 21 with dyseidetic dy slexia, classified by Boder criteria, were compared to 90 control group par ticipants (45 matched for age and 45 for reading level) on the Composite Me mory Index (CMI) score from the Test of Memory and Learning (TOMAL). CMI sc ores were significantly lower for children with dyslexia (p < .0001). Plott ing average subtest score profiles fbr all reader groups revealed auditory sequential memory impairments for both types of readers with dyslexia, and multiple strengths for good readers. Dysphonetic and dyseidetic dyslexia pr ofiles were nearly identical. For Study 5 average linkage cluster analysis was performed using principal components derived from subtests of the TOMAL . Homogeneous clusters of normal readers and children with reading disabili ties emerged. Results indicated that qualitatively distinct subtypes of rea ders with dyslexia exist. (C) 1999 National Academy of Neuropsychology. Pub lished by Elsevier Science Ltd.