Neologistic jargon sparing numbers: A category-specific phonological impairment

We report the case of a patient suffering from a severe neologistic jargon sparing number words. Neologisms resulted from pervasive phoneme substitutions with frequent preservation of the overall syllabic structure (e.g. /revolver/ --> /reveltil/). Word and nonword reading, as well as picture naming, were equally affected. No significant influence of frequency, imageability, and grammatical class was found. In striking contrast with this severe speech impairment, the patient made virtually no phonological errors when reading aloud arabic or spelled-out numerals, but made frequent word selection errors (e.g. 250 --> "four hundred and sixty"). This observation indicates that during speech planning, different categories of words are processed by separable brain systems down to the level of phoneme selection, a more peripheral level than was previously assumed. Number words may be singled out during phonological processing either because they constitute a particular semantic category, or because they benefit from special brain mechanisms devoted to the production of "automatic speech", or because they are the elementary buildings blocks of speech during the production of complex numerals.