A Review of the Literature

THE JOURNAL OF SPECIAL EDUCATION VOL. 40/NO. 3/2006/PP. 171–183 171 In the early part of the 20th century, the field of learning dis-abilities was still in its infancy. At that time, Dr. Samuel Orton, a child neurologist, estimated that approximately 10 % of the school population had reading disabilities and speculated that reading problems were caused by neurological deficits. Orton’s early conclusions formed two major tenets of the characteristics of dyslexia: (a) reading problems were caused by strephosym-bolia (or twisted symbols), and (b) a lack of brain hemisphere dominance caused information to be processed in both hemi-spheres, resulting in mirror images (e.g., reversals of the let-ters b and d). Although Orton’s speculated causes of reading disabili-ties have not stood the test of time (phonological processing problems are currently accepted as the primary cause of read-ing disabilities), his ideas about appropriate reading instruction have. Specifically, Orton (1937) stated that the instructional approach should attempt to capitalize [sic] their [students’] auditory competence by teaching them the phonetic equiva-lents of the printed letters and the process of blend-ing sequences of such equivalents so that they might be able to produce for themselves the spoken form of the word from its graphic counterpart. (p. 159