Representing written vowels in university students with dyslexia compared with normal Hebrew readers.

The study investigates dyslexic and normal Hebrew readers' perception of words containing a vowel letter in different orthographic and morphological contexts. In the first experiment, 72 undergraduate education students (half diagnosed with reading disabilities and half normal readers) were asked to judge pointed words with different morphological structures with and without the grapheme W. Half of the words had consistent (obligatory) W and half had inconsistent (optional) W. In the second experiment, the same procedure was repeated using the same words without pointing marks. Response latencies and accuracy were measured. In both experiments, dyslexic readers did less well than normal readers, they had lower scores on accurate lexical decisions, and they took more time over these decisions. They also exhibited some deviant patterns indicating that they cannot make use of orthographic and morphological cues which are available to normal readers, especially in the pointed experiment. Processing pointed words placed a heavier cognitive burden on the dyslexic readers. These findings are in line with other studies of adult dyslexic reader/writers, and support a reading / spelling processing model, which claims that internal orthographic representations of words are increasingly strengthened with each exposure during reading, but not all graphemes are strengthened equally. The general implication is that the ambiguities that exist in the relationships between orthography, phonology and morphology underlie spelling knowledge and are particularly difficult for dyslexic readers.