Preserved calculation skills in a case of semantic dementia.

We present the case of a patient, BET, with a profound semantic dementia who shows a selective preservation of many aspects of number knowledge. In the context of an otherwise global loss of visual and verbal semantic knowledge, our patient demonstrates relatively intact number processing and numerical calculation in both the verbal and visual domain. More remarkably, BET is able to harness her intact calculation skills to number problem solving tasks. Our report provides further evidence that high-level non-verbal reasoning may persist in the absence of any viable language skills.