Heterogeneity in adult dyslexic readers:: Relating processing skills to the speed and accuracy of oral text reading

Subgroups of Finnish dyslexic adults (N = 84) displaying, relative to each other, a distinctive combination of accuracy and speed of oral text reading were compared in phonological and orthographic processing, verbal short-term memory and reading habits. Inaccurate phonological decoding appeared to determine the number of errors made in text reading, while inability to utilize effectively rapid lexical access of words manifested as slow text reading speed. Phonological and orthographic word recognition processes were less tightly integrated among dyslexic than normal readers. Our results indicate that advanced orthographic processing skills might help a number of the dyslexic readers to compensate for their serious phonological deficits. The subgroups also differed from each other in reading habits. A relatively fast reading speed, even with numerous errors, appears to be more rewarding in everyday reading than a slower but more accurate reading style.