Transcoding Sound to Spelling: Single or Multiple Sound Unit Correspondence?

Abstract

We report a detailed analysis of the written spelling of an aphasic patient, KT, in whom no viable comprehension could be demonstrated despite accurate repetition and fluent speech (transcortical sensory aphasia). His spelling conformed in all respects with the definition of an orthographic/lexical dysgraphic such that his writing of regular, orthographically unambiguous words and nonsense syllables was entirely satisfactory. Lexical variables such as word class or word frequency had no effect on his performance. Irregular or ambiguously spelled words were selectively impaired. An independent measure of orthographical ambiguity was defined in relation to the frequency with which a phoneme was represented by a particular grapheme and the number of alternative graphemes for the same sound. For the majority of sounds studied, KT was able to demonstrate the use of all the most frequent alternative transcoding units for each sound but he did not use them in the same frequency with which they occurred in written English. Thus his performance bore little or no relationship to predictions based on single phoneme/grapheme counts and there was unequivocal evidence for his ability to use multiple sound-unit correspondences.

The effect of the number of syllables on handwriting production

“…Case studies of patients with a graphemic buffer disorder (Baxter & Warrington, 1987;Caramazza & Miceli, 1990;Zesiger & de Partz, 1997) indicate that the recall of orthographic information is indeed regulated by the syllable structure of words. It seems that the storage of orthographic information in the graphemic buffer-once lexical access has occurred for words and chunking has taken place for pseudowords-is achieved via a rehearsal process, which is sensitive to the processing load (measured in number of syllables).…”

Attentional strategic control over nonlexical and lexical processing in written spelling to dictation in adults

“…Second, the analyses of spelling errors exhibited by certain patients are consistent with the involvement of sublexical as well as lexical knowledge. In effect, some patients have been found to be able to produce nonwords while performing poorly on words, and more particularly, irregular words (e.g., Baxter & Warrington, 1987;Beauvois & Dérouesné, 1981;Behrmann & Bub, 1992;Goodman & Caramazza, 1986;Sanders & Caramazza, 1990), while the opposite observation has been reported in other patients (e.g., Baxter & Warrington, 1985;Bub & Kertesz, 1982;Shallice, 1981). This double dissociation has been taken as strong support for the existence of 59…”

Do Phonological Codes Constrain the Selection of Orthographic Codes in Written Picture Naming?

“…For example, Baxter and Warrington (1987) have suggested that only a single idiosyncratic mapping should be represented. In constrast, Goodman and Caramazza (1986) have proposed that multiple phoneme-tographeme mappings are represented for each phoneme, e.g., /k/ → c, k, qu.…”