Recognizing identical versus similar categorically related common objects: further evidence for degraded gist representations in amnesia.

Studies have shown lower false recognition of semantically related lure words in patients with global amnesia than in matched controls. This pattern has been interpreted as suggesting that medial temporal and diencephalic structures that are damaged in amnesia and that contribute to veridical memory also contribute to false recognition. It has been argued that whereas controls form and retain a well-organized representation of the semantic gist of studied items, patients with amnesia can retain only a degraded gist representation. However, these studies are subject to an alternative interpretation involving greater source confusions in controls. The authors used a categorized-pictures paradigm to test recognition under conditions in which source confusions were unlikely to occur. Relative to controls, patients with amnesia showed reduced false recognition of categorically related pictorial lures, thereby supporting the notion of degraded gist representations in amnesia.