The role of phonology in syllabic structure in the time course of typing: Evidence from aphasia

In previous studies, it was demonstrated that the time course of typing and handwriting follows a syllabic pattern. This raises the question of whether this pattern is caused by phonological processes or whether it reflects an independent structure of the graphemic pathway. The case of AB is presented. He is a fluent German aphasic, who, in spite of the absence of articulatory deficits, displays superior written word production compared to his spoken word production. It is argued that AB’s phonological impairment arises from damage to the lexical system, rather than to the sublexical system. Additionally, AB suffers from severe damage to the phoneme-grapheme-conversion system, as indicated by his severe impairment to write non-words to dictation. It is therefore suggested that AB’s spelling is not phonologically mediated, either by lexical or by sublexical processes. The analysis of the time course of AB’s single word typing reveals no syllabic effects as it was found in healthy adult controls. In contrast to healthy adult controls though, AB does not show a systematically increased delay at the syllable onsets within words during single word typing. This finding suggests that AB is unable to group graphemes into syllables or syllable-like units. The implications of this finding for the view of an autonomous orthographic syllable are discussed, i.e. an orthographic syllable being independent of any phonological influences.