Memory updating is an adaptive function that requires people's registry of changes of episodes. However, the research on the role of prior knowledge on memory updating among older adults is scant. We instructed young and older adults to learn two sets of pairs with overlapping scene (A) on Day 1 (A-B) and Day 2 (A-C) and tested the competing memories on Day 3. We further manipulated the schema-congruency between item (B/C) and scene (A). Young adults performed comparatively well in the A-B and A-C memory tests, and showed no difference under different congruency conditions. However, memory updating among older adults was moderated by prior knowledge, with better memory performance in A-C test relative to A-B test when the to-be-updated item C was schema-congruent, however, with poorer memory performance in the A-C test when the to-be-updated item is schema-incongruent. This study advances the understanding that prior knowledge significantly contributes to memory updating among older adults. They would experience retroactive interference when the to-be-updated memories were consistent with their prior knowledge, yet proactive interference when the to-be-updated memories were inconsistent with their prior knowledge. Meanwhile, prior knowledge among young adults does not affect memory updating, given that their memory patterns are consistent across congruency conditions.
Keywords: AB-AC paradigm; Aging; episodic memory updating; prior knowledge.