FROM GRAPHEMES TO ABSTRACT LETTER SHAPES - LEVELS OF REPRESENTATION IN WRITTEN SPELLING

The letter substitution errors of 2 dysgraphic subjects who, despite r elatively intact oral spelling, made well-formed letter substitution e rrors in written spelling, were studied. Many of these errors bear a g eneral physical similarity to the intended target. Analyses revealed t hat this similarity apparently was based on the features of the compon ent strokes of letters rather than on visuospatial characteristics. A comparison of these subjects' letter substitution errors with those of 2 other individuals with brain damage, whose damage was at a differen t level of processing, revealed that the latter subjects' errors are n ot explicable in terms of stroke-feature similarity. Strong support wa s found for the computation of multiple representational types in the course of written spelling. This system includes a relatively abstract , effector-independent representational level that specifies the featu res of the component strokes of letters.