Episodic memory and ageing: the role of cognitive reserve factors and cognitive resources according to task difficulty.

Abstract

Episodic memory is the memory system which is most affected by ageing. However, similar memory decline is not seen in all older adults. Various cognitive reserve factors, such as the Openness Personality Trait and level of educational attainment, and cognitive resources linked to these factors, such as executive control and crystallised knowledge, can predict older adults' memory performance. This study examined the link between and the role of these variables in older adults' memory performances according to the difficulty of the task. Forty participants (aged between 60 and 82) learned 24 paired words with two encoding conditions (reading and generation), and then performed a cued recall. They were asked for their level of educational attainment, and their openness, executive control and crystallised knowledge levels were respectively measured using a personality questionnaire (Big Five), an inhibition test (Stroop) and a vocabulary test (Mill Hill). Only crystallised knowledge predicts older adults' recall of generated words while openness and executive control predict and mediate the effect of level of education on older adults' recall of read words. Openness is a reserve factor and is an essential component, along with executive control, in difficult memory tasks.