MODALITY-SPECIFIC PHONOLOGICAL ALEXIA

Following a stroke, patient TL presented with a pure alexia that also displayed the features of phonological alexia (poor pseudoword reading , part-of-speech effect). This pattern was absent, however, when words were spelled aloud to TL. We propose that, with visual input, orthogr aphic word forms are only weakly activated in TL. This weak activation succeeds in activating strongly represented semantic codes-such as co ncrete nouns-but not weakly represented semantic codes-such as functor words-resulting in a part-of-speech effect. When words are spelled al oud, the input is sufficient to activate the orthographic word form st rongly, and all words are identified. Most pure alexia patients can sp ell written words aloud to themselves (hence they are often called let ter-by-letter readers), and consequently do not show symptoms of seman tic reading. TL, whose letter-naming abilities are poor, cannot resort to this alternative strategy, and so the consequences of a weakly act ivated orthographic word form are revealed.