Abstract

Surface dysgraphia is a (symptom of a) neurological language disorder with a loss of lexicosemantic writing routines and preserved segmental Phoneme-to-Grapheme conversion (PGC). Surface dysgraphic subjects write words and non-words phonologically plausible but with orthographic errors concerning words with ambigue PGC. Such an isolated use of the PGC routine allows us to focus analysis on segmental processing in writing. H.S., a German patient suffering from primary progressive aphasia, showed typical surface dysgraphic errors in writing words to dictation. The analysis of his responses revealed the implicit knowledge of syllabic principles and their application in writing. He could phonologically differenciate native and non-native sounding items and showed context-sensitivity in PGC (as for initial /f/). Furthermore H.S. succesfully applied the syllabic rules for inserting the silent '·syllable initial h''. Moreover the patient payed attention to the graphemic "syllable weight'' in realising the lengthening-h - that is he "stretched" graphematically short syllables by inserting it and "compressed" long syllables by leaving it out. Doing so he paralleled the probability for the existence of the lengthening-h in German. But he even took notice of the graphemic syllable weight in realizing lt/ as - which the German writing system does not use analogously. Thus the segmental ''surface•· routine works in relative autonomy of lexical routines as it is supposed in the logogen-model of word processing (cf. Patterson, 1988). Phonemegrapheme-conversion applies various syllabic rules and principles. The model will have to be specified in this point.