DEEP DYSLEXIC PHENOMENA IN A LETTER-BY-LETTER READER

Numerous accounts of pure alexia have suggested that prelexical impair ment precludes rapid access to orthographic information in patients wi th the disorder. We report a patient with features of both pure and pa rtially recovered deep dyslexia in whom we demonstrate prelexical defi cits in maintaining a reliable abstract representation of the right si de of letter arrays, as well as in modulating a ''spotlight'' of visua l attention. These deficits, we suggest, encourage the patients's use of a letter-by-letter reading strategy; despite them, however, he demo nstrates rapid, accurate reading of some, but not all classes of words . Furthermore, the patient's reading is influenced by both prelexical and lexical-semantic factors such that speed and accuracy are optimal for high imageability nouns of few letters. Finally, the patient accur ately names orally spelled words of all classes. Taken together, these data are consistent with the hypothesis that rapid reading may be ena bled by lexical-semantic support from a right hemisphere-mediated proc essing system which recognizes words as wholes, thereby mitigating the effect of the prelexical deficits. (C) 1996 Academic Press, Inc.