Relational binding and holistic retrieval in ageing.

Episodic memory binds together diverse elements of an event into a cohesive unit. This property enables the reconstruction of multidimensional experiences when triggered by a cue related to a past event via pattern completion processes. Such holistic retrieval is evident in young adults, as shown by dependency in the retrieval success for different associations from the same event [Horner, A. J., & Burgess, N. The associative structure of memory for multi-element events. Journal of Experimental Psychology: General, 142(4), 1370-1383. https://doi.org/10.1037/a0033626, 2013; Horner, A. J., & Burgess, N. (2014). Pattern completion in multielement event engrams. Current Biology, 24(9), 988-992. https://doi.org/10.1016/j.cub.2014.03.012, 2014]. Aspects of episodic memory capacity are vulnerable to ageing processes, including reduced abilities to form linkages among aspects of an event through relational binding (Naveh-Benjamin, 2000). Here, we used dependency analyses to examine whether older adults retrieve events holistically, and whether the degree of holistic retrieval declines with old age. We found that both young and older adults retrieved events as an integrated unit, but older adults showed a lower magnitude of holistic retrieval compared to young adults. Holistic retrieval declined with advancing age, even after controlling for pairwise relational binding performance. These results suggest that a decline in holistic retrieval is an aspect of episodic memory decrements in cognitive ageing.