Feeling-of-knowing in fact retrieval: further evidence for preservation in early Alzheimer's disease.

The ability to retrieve and monitor factual information varying in datedness (i.e., dated vs. contemporary) was examined in healthy older adults and patients in an early phase of Alzheimer's disease (AD). Subjects were given free recall and multiple-choice recognition tests of 48 general knowledge questions. For all questions not responded to in recall, subjects made feeling-of-knowing (FOK) judgments. Results indicated dementia-related deficits in both recall and recognition, although both groups showed better recall and recognition with the dated compared with the contemporary questions. Importantly, despite deficits in fact retrieval, the AD patients showed intact monitoring of stored knowledge, as indicated by equivalent FOK accuracy for both groups. In addition, FOK accuracy was similar for the dated and the contemporary information in both groups, suggesting independence between level of general knowledge and the ability to supervise information stored in memory.