Double dissociations of word and number processing in auditory and written modalities: a case study.

We report an individual with a massive left-hemisphere lesion, who showed reverse patterns of dissociations between word and number processing in two modalities (auditory comprehension and written production). His performance in auditory comprehension was perfect for words, but severely impaired for numbers. In written production, he performed significantly better at writing numbers (both Arabic numbers and word numbers) than writing words. His visual comprehension fell into normal range for words and numbers while his oral production was at floor for both. This case profile adds further evidence to the functional/neural segregation of word and number processing systems.