Abstract
Age-related changes in brain structure and memory are well-documented; the relationship between these changes and the spontaneous use of memory strategies, however, remains under-researched. Self-initiated strategies, such as semantic clustering, are known to facilitate episodic memory performance, yet few studies have examined how age-related gray matter volume differences are associated with the use of these strategies. The current study aimed to address whether gray matter volume differences are related to age-related differences in memory performance and semantic clustering usage during learning on the CVLT. We assessed 9 prefrontal and hippocampal subregions, based on their association with semantic clustering usage, in 60 younger and 47 older adults. From these analyses, larger gray matter volumes within the left pars triangularis and right rostral middle frontal gyri were positively associated with overall memory performance (Trial 5 and long-delayed free recall) in older adults. Volumes within the left pars triangularis were also positively associated with increases in raw memory scores across all learning trials in older adults. Larger gray matter volumes within the right hippocampal subfields CA1 and CA3 were positively associated with greater semantic clustering use during Trial 5 in older adults. Volumes within the right CA3 were also positively correlated with an increase in semantic clustering use over all learning trials in older adults. For all of the previously mentioned tests, larger gray matter volumes in the respective brain regions showed negative trends in younger adults, showing an under-researched age discrepancy.