In the present fMRI study, we examined age-related differences in episodic richness on the spatiotemporal dynamics
of AM retrieval. Age-related reductions were primarily observed during the later elaboration processes of AM retrieval, with older adults showing a reduction in the recruitment of the hippocampus and PFC. Linking these results to the behavioral reductions in episodic richness in older adults, we found that functional activity in these regions
was attenuated for AMs that were more episodically detailed. Further, we found an age-related reduction in the top-down modulation of the PFC on the hippocampus by episodic richness, possibly reflecting fewer controlled processes operating on the recovery of information in the hippocampus.
In sum, the present findings suggest that the age-related deficit in the episodic richness of AMs is associated
with an overall reduction in the rich elaboration of these memories, where older adults show less top-down
modulation of the PFC on the hippocampus.