Semantic, episodic, and autobiographical memory in a postmeningitic amnesic patient.

This study is concerned with the semantic and episodic memory performance of a highly intelligent and intellectually unimpaired patient, K.J., who became amnesic following meningitis. Although densely amnesic he showed unimpaired performance on tests of vocabulary and verbal fluency, while both speed and accuracy on semantic category judgment and sentence verification tests are unimpaired. It is concluded that semantic memory performance may be intact despite dense amnesia. However, this does not necessarily imply separate semantic and episodic memory systems. K.J. showed an impaired capacity for registering new material in semantic memory, and apparently normal autobiographical memory for events occurring well before his illness. The simplest interpretation of our results would therefore appear to be in terms of the sparing of old and overlearned memories rather than the specific preservation of semantic memory.