The Effects of Attention on Age-related Relational Memory Deficits: fMRI Evidence from a Novel Attentional Manipulation

摘要

Numerous studies have documented that older adults (OAs)ndo not perform as well as young adults (YAs) when task demandsnrequire the establishment or retrieval of a novel linknbetween previously unrelated information (relational memory:nRM). Nonetheless, the source of this age-related RM deficit remainsnunspecified. One of the most widely investigated factorsnis an age-related reduction in attentional resources. To investigatenthis factor, previous researchers have tested whetherndividing YAsʼ attention during encoding equated their RM performancento that of OAs. However, results from these studiesnfailed to replicate the age-related RM impairment observed innaging. The current study investigated whether a reduction innattentional resources for processing of relational informationn(i.e., relational attention) underlies age-related RM deficits.nUsing fMRI, we examined whether the effect of reduced attentionalnresources for processing of relational information isnsimilar to that observed in aging at both behavioral and neuralnlevels. The behavioral results showed that reduced attentionalnresources for relational information during encoding equatednYAs RM performance to that of OAs. Furthermore, the fMRI resultsndemonstrated that both aging, as well as reductions innrelational attention in YAs, significantly reduced activity in brainnareas associated with successful RM formation, namely, the ventrolateralnand dorsolateral PFC, superior and inferior parietal regions,nand left hippocampus. Such converging evidence fromnbehavioral and neuroimaging studies suggests that a reductionnin attentional resources for relational information is a criticalnfactor for the RM deficit observed in aging. ■