Overview: For a century and a half, brain–behavior correlates in language were studied via the lesion approach, in which functional deficits after localized neurological damage are used to deduce the brain's organization. While much of the basic information gleaned from this research tradition still holds and new lesion-based discoveries continue to be made, modern advances with in vivo imaging techniques reveal that language processing in fact recruits many brain areas. In particular, different aspects of spoken and written language, such as orthography and semantics, require different kinds of neuropsychological processing. Given the complex distribution of language-related skills in the brain, the heterogeneity of dyslexic profiles is not surprising. In the end, it is likely that this very heterogeneity will prove key not just to unlocking the true nature of dyslexia but to understanding better the spoken and written language systems themselves.