Automatization aspects of dyslexia: speed limitations in word identification, sensitivity to increasing task demands, and orthographic compensation.

A study is presented in which three characteristics of dyslexia were examined: (a) speed limitations in word identification, (b) sensitivity to increasing task demands, and (c) orthographic compensation. Ten students with dyslexia (10 years old) were compared to 10 chronological-age controls and 20 reading-age controls on their performance in reading. Response latencies of the students with dyslexia were slower when familiar words, letter clusters, and nonwords had to be named. A larger word-frequency effect and a larger word-length effect in the these students indicates that they have difficulty with increasing task demands. In addition, a subword-frequency effect was found to be larger in the students with dyslexia. These differences among the three groups of students are interpreted in terms of automatization. Furthermore, it is suggested that students with dyslexia may have a preference for large orthographic units, which is used as a compensatory tool in reading.