Preserved semantic learning in an amnesic patient.

A case study is reported of an amnesic patient (KN), who displayed an ability to learn a substantial body of new visual and verbal semantic concepts, despite having a severe deficit in episodic memory. In two experiments, using an errorless learning paradigm, he was able to perform at a level close to that of his wife, who served as a control subject. When recall of material was retested after a delay of several months, during which time there were no further learning sessions, his retention was at least as good as, if not better, than that of his wife. This is taken as further evidence for the dissociation of semantic and episodic processes in amnesia. It also provides further evidence for the role of "errorless learning" in efficient acquisition of new facts in amnesia.