Inferring semantic organization from refractory access dysphasia: further replication in the domains of geography and proper nouns but not concrete and abstract concepts.

Patients with "refractory access dysphasia" have been a source of unique insight into the organization of previously unexplored domains of semantic knowledge (i.e., proper nouns, geography, concrete and abstract concepts). However, much of the relevant data have been based on the performance of a small number of patients. Here, we present 2 patients who both display a "refractory access" pattern of performance on spoken-word-written-word matching tasks and test their performance in the domains of famous people, geography, and abstract and concrete words. While these patients show performance similar to that for the previously reported patients in the domains of famous people and geography, they show a very different pattern of performance with abstract and concrete nouns. We discuss possible reasons why patients may differ in performance and evidence for and against the "differential frameworks" hypothesis for the organization of concrete and abstract concepts.