Wednesday March 18, 09:20-10:20

Memory Dissociations: Evidence from a Longitudinal Study on Cognition, Health, and Aging

Lars-Göran Nilsson

(Department of Psychology, Stockholm University, Sweden)

In a longitudinal study on cognition, health, and aging, we have discovered several notable dissociations, which are interpreted as further support for separate episodic memory and semantic memory systems. The 3000 subjects participating in the study were randomly drawn from the population of a city in northern Sweden. At the first wave of data collection in 1988-1990 the subjects were 35, 40, 45, 50, 55, 60, 65, 70,75, and 80 years of age. A second wave of data collection took place in1993-1995; a third wave will take place in 1998-2000. The examination of participants at each test occasion includes a total of almost 2000variables assessing episodic memory, semantic memory, priming, procedural memory, social life, health status, and some genetic markers. The results show an age deficit in episodic memory tasks, but not in semantic memory tasks. The educational level of the participants affects semantic memory,but not episodic memory. Various health related variables influence the performance in episodic memory tasks, but not the performance in semantic memory tasks. Whenever an effect of social variables has been found, it holds for episodic memory tasks, not for semantic memory tasks. Genetic markers related to the immune system and Apolipoprotein E are associated with performance differences in episodic memory tasks, but not in semantic memory tasks. The importance of the dissociations demonstrated in this longitudinal study will be discussed in relationship to other dissociations between episodic and semantic memory obtained in previous research.