Lexical morphology and the two orthographic routes

We report a case of dysgraphic performance in which we have documented the selective preservation of suffix spelling in the context of the phonologically plausible spelling of word stems (e.g. surfed spelled as sourphed, and not as sourpht). The preservation of suffix spelling is observed consistently in spite of the fact that the spelling for the suffix corresponds to more than one phonological form. We argue that the interpretation of such an error pattern requires that we assume that the stem material is processed via phonology-to-orthography conversion, whereas the suffix material is processed lexically. We conclude that the results are incompatible with an exclusively whole-word view of lexical representation and processing and requires, instead, that we assume a lexical orthographic system in which morphologically complex forms are represented in a compositional manner.