The role of the Graphemic Buffer in spelling: evidence from a case of acquired dysgraphia.

A dysgraphic patient is described whose deficit is hypothesized to arise from selective damage to the Graphemic Buffer. The patient’s roughly comparable difficulties in oral and written spelling and comparable spelling difficulties in written naming, delayed copy and spelling-to-dictation rule out the hypothesis of selective damage to either input or output mechanisms. More importantly, the nature of the errors produced by the patient and the fact that these errors were distributed virtually identically for familiar and novel words. were taken as strong evidence for the hypothesis that L. B. ‘s spelling disorder results from selective damage to the Graphemic Buffer. Various aspects of the patient’s performance are discussed in relation to a functional architecture of the spelling process and in terms of the processing structure of the Graphemic Buffer, *The research reported in this paper was supported by NIH grant NS22201 to The Johns Hopkins University and by a grant from the CNR, Italy. We would like to thank Bill Badecker, Roberta Goodman, Brenda Martin, Tim Shallice and an anonymous referee for their comments on an earlier version of this paper. We also thank Kathy Sporney for her assistance in the preparation of this manuscript. Requests for reprints should be addressed to: Alfonso Caramazza, Cognitive Neuropsychology Laboratory, Ames Hall, The Johns Hopkins University, Baltimore, MD 21218, U.S.A. OOlO-0277/87/$8.60