Monitoring of general knowledge: evidence for preservation in early Alzheimer's disease.

The ability to retrieve and monitor factual information was examined in normal old adults and patients with a mild Alzheimer's disease (AD). Subjects were given free recall and multiple-choice recognition tests of 48 general knowledge questions. For both tests, subjects made confidence ratings regarding the certainty of their answers, and they also made feeling-of-knowing ratings for those questions they did not answer in recall. Results indicated a superiority of controls over patients in recall that was somewhat reduced in recognition. However, there were no group differences in any of the slopes relating rating to accuracy: recall and recognition as a function of confidence rating, and recognition of questions not answered in recall as a function of feeling-of-knowing. This pattern of outcome indicates that early AD is associated with a deficit in fact-retrieval, although the ability to monitor stored general knowledge may be intact.