Production and identification repetition priming in amnestic mild cognitive impairment

The experiment reported here examined implicit memory function, as measured through repetition priming, in amnestic mild cognitive impairment (MCI) to examine whether impairments exist in this aspect of memory function. Young adults, healthy older controls, Alzheimer's disease patients, and MCI participants were asked to perform two types of implicit memory tests (word stem completion and threshold identification repetition priming tasks), as well as a recognition test for studied items. As expected, young adults performed better than the other participants on the recognition test and the word stem completion task; there was equivalent priming across groups on the word identification task. While both the older control and MCI participants showed lower levels of priming on the word stem completion task relative to the young adults, the magnitude of priming was equivalent for these two groups, and reliably greater than that of the dementia participants. These results suggest that not all aspects of memory function are impaired in MCI relative to healthy aging.