Cortico-hippocampal interactions underlie schema-supported memory encoding in older adults

Area of Science:

• Cognitive Neuroscience
• Neuroimaging
• Aging Research

Background:

• Episodic memory declines with age, but semantic knowledge can mitigate this.
• Schema knowledge enhances memory, particularly in older adults (OAs).
• Previous research linked schema use to ventromedial prefrontal cortex (vmPFC) and hippocampus (HPC), mainly in young adults (YAs).

Purpose of the Study:

• To investigate the neural mechanisms of schema-induced episodic memory enhancement in OAs.
• To compare how schemas boost memory in OAs versus YAs using fMRI.
• To explore age-related differences in cortico-hippocampal interactions during memory encoding.

Main Methods:

• Functional magnetic resonance imaging (fMRI) during encoding of scene-object pairs with varying schema congruency.
• Memory recall testing the day after encoding.
• Analysis of cortical modulation of the hippocampus (HPC) predicting subsequent memory.

Main Results:

• Schema congruency enhanced object memory in both YAs and OAs, with a larger effect in OAs.
• vmPFC modulation of HPC enhanced memory in both age groups.
• Angular gyrus (AG) modulation of HPC enhanced memory specifically in OAs.
• OAs showed preferential AG-HPC interaction, suggesting compensatory semantic knowledge use.

Conclusions:

• Schemas significantly boost episodic memory encoding in older adults.
• Older adults utilize distinct cortico-hippocampal pathways, particularly AG-HPC, for schema-based memory enhancement.
• Findings highlight age-related differences in neural strategies for leveraging semantic knowledge to support memory.