EPISODIC MEMORY, SEMANTIC MEMORY, AND AMNESIA

Episodic memory and semantic memory are two types of declarative memor y. There have been two principal views about how this distinction migh t be reflected in the organization of memory functions in the brain. O ne view, that episodic memory and semantic memory are both dependent o n the integrity of medial temporal lobe and midline diencephalic struc tures, predicts that amnesic patients with medial temporal lobe/dience phalic damage should be proportionately impaired in both episodic and semantic memory. An alternative view is that the capacity for semantic memory is spared, or partially spared, in amnesia relative to episodi c memory ability. This article reviews two kinds of relevant data: 1) case studies where amnesia has occurred early in childhood, before muc h of an individual's semantic knowledge has been acquired, and 2) expe rimental studies with amnesic patients of fact and event learning, rem embering and knowing, and remote memory. The data provide no compellin g support for the view that episodic and semantic memory are affected differently in medial temporal lobe/diencephalic amnesia. However, epi sodic and semantic memory may be dissociable in those amnesic patients who additionally have severe frontal lobe damage. (C) 1998 Wiley-Liss , Inc.