Association of Hippocampal Substructure Resting-State Functional Connectivity with Memory Performance in Older Adults.

•Greater medial temporal lobe functional engagement is associated with pre-clinical dementia pathophysiology.•We do not know whether these processes are related to global or anatomically specific aspects of medial temporal lobe function.•We characterized the resting-state functional connectivity of medial temporal lobe substructures to identify which aspect(s) correlate with memory performance.•Left dentate-lingual gyri connectivity strongly correlated with memory performance, whereas the other aspects of medial temporal lobe connectivity did not.•Rather than global hyperconnectivity, higher left dentate-lingual gyri connectivity specifically marks pre-clinical variability in memory performance.