Further evidence of preserved memory function in Alzheimer's disease

Abstract

SUMMARYMemory performance of elderly patients in the early stages of Alzheimer's disease (DAT) was compared with that of elderly control subjects. In explicit tests of recognition memory, which involve conscious recollection, the DAT patients were grossly impaired. In implicit tests of anagram solution and wordstem completion, which do not require conscious recollection, the DAT patients were not impaired. These findings further support the idea that a separate memory system, episodic memory, underlies conscious recollection, that it is this system which is most commonly damaged in amnesia, and that memory systems not involving conscious recollection may be spared in the early stages of Alzheimer's disease.

Repetition priming in normal aging and Alzheimer's disease: A review of findings and theories.

“…This theory explains the finding that category exemplar generation is intact in AD when study-and test-phase operations are identical but not when they are mismatched (Maki & Knopman, 1996). Although this is a viable explanation for this result, the theory cannot explain the numerous examples of normal AD priming following unmatched study-and test-phase operations (e.g., Abbenhuis et al, 1990;Balota & Ferraro, 1996;Christensen et al, 1992;Fennema-Notestine et al, 1994;Perfect et al, 1992;Russo & Spinnler, 1994;Scott et al, 1991). For example, normal priming has been demonstrated after words were read silently in the study phase and stems of words were completed in the test phase (e.g., Deweer et al, 1994) and when words were generated in the study phase and identified in brief presentations in the test phase (Fleischman et al, 1995).…”

Direct Interventions for Improving the Performance of Individuals with Alzheimer's Disease

“…Because of this lack of conscious recollection of the training itself, SRT is thought to engage implicit or unconscious memory processes, 38 which are considered relatively preserved in AD. 26,39 An advantage of SRT is that it can be nested in other tasks, such as having a conversation or reminiscing. Further, SRT is highly flexible because the target response being trained can be verbal, as in answering questions or recalling information, or nonverbal, as in demonstrating a safety precaution or a compensatory swallow technique.…”

Implicit memory for words presented in short texts is preserved in Alzheimer's disease

“…First observations revealed a preservation of perceptual priming in AD (Moscovitch, 1982;Ober & Shenaut, 1988) but Salmon & Heindel (1992) observed a deficit in lexical priming and suggested that this deficit could be an early signature of the disease. With the aid of stem completion tests, many studies have confirmed the perturbation of priming in AD (Shimamura et al 1987 ;Salmon et al 1988 ;Heindel et al 1989;Bondi & Kasniak, 1991 ;Keane et al 1991 ;Scott et al 1991 ;Gabrieli et al 1994;Downes et al 1996;Heindel et al 1997 ;Carlesimo et al 1999). Moreover, these data suggest that conceptual priming is altered (Brandt et al 1988 ;Huff et al 1988 ;Salmon et al 1988 ;Grober et al 1992;Monti et al 1996 ;Carlesimo et al 1999), whereas perceptual priming seems to be preserved (Keane et al 1991(Keane et al , 1994Fleishman et al 1995 ;Koivisto et al 1996).…”