PHONOLOGICALLY BASED SPELLING-ERRORS AND THEIR IMPLICATIONS IN THE SPECIFICATION OF PHONOLOGY TO ORTHOGRAPHY CONVERSION PROCESSES

We report a case of severe dysgraphia whose characteristics suggest an exclusive reliance on sublexical phonology to orthography conversion processes. In addition to numerous phonologically plausible errors (PP Es), ML produces many context errors and grapheme substitutions, indic ating that conversion processes are also impaired. Interestingly, most of the errors produced on consonants consist of substitutions of lett ers corresponding to voiced phonemes with letters corresponding to unv oiced ones and vice-versa-a phenomenon which is much more frequent in written than in oral spelling. We conclude that conversion processes r epresent correspondences between graphemes and phonological features r ather than between graphemes and phonemes.