Measures of recognition and source memory and their relation to age and Alzheimer's disease
Source memory is the process of recalling a memory's origins. Researchers investigating differences across young, nondemented old (NDO), and subjects with diseases like Alzheimer's disease (AD) find conflicting results. Some conclude age and disease particularly impair source memory. Others find no impairment or none greater than general memory impairment. However, methodological limitations compromise those conclusions. For example, many source memory studies are not based on memory and decision-making models, and many studies of source memory changes in aging and dementia use different testing procedures across subjects confounding relationships among independent variables. The present study uses model-based approaches (multinomial and logistic regression models) to generate and analyze source memory scores while all subjects receive the same testing procedures. Direct and indirect source memory measures are analyzed. Twenty undergraduates (young), twenty-one NDO, and twenty AD subjects participated. All subjects completed a recognition memory test. Source was varied by presenting some items as pictures and some as words during the study phase. At testing, subjects received items that were all pictures or all words. This allowed for testing source memory indirectly by observing the effect that test item modality had on item detection. Multinomial analyses found young subjects had greater source and item memory scores than NDO subjects. Logistic regression analyses found no difference in source memory scores but better item memory in the young versus NDO subjects. In both analyses, NDO subjects had greater source memory and picture detection than AD subjects. Multinomial analysis revealed NDO subjects had greater word detection than AD subjects. Analyses of indirect source memory measures suggested test item modality had an effect on picture detection but not word detection. The effect was not equivalent across groups. The young did not have enhanced detection while NDO and AD subjects did. All groups showed better memory for material presented pictorially. Both models yielded similar results but differ greatly theoretically and practically. Research on age and disease-related cognitive changes like this project could lead to development of tests sensitive to the earliest stages of cognitive-impairing, age-related diseases or identify individuals at high-risk for such disease development.
Flynn, Sean Patrick, "Measures of recognition and source memory and their relation to age and Alzheimer's disease" (2000). ETD Collection for Fordham University. AAI9955963.