Brain structure and episodic learning rate in cognitively healthy ageing

Area of Science:

• Neuroscience
• Cognitive Aging
• Neuroimaging

Background:

• Age-related memory decline impacts cognitive function.
• Episodic memory retrieval is well-studied in aging, but learning processes are less understood.
• Brain structure changes are associated with age-related cognitive changes.

Purpose of the Study:

• To investigate the neural correlates of episodic learning rate in a large cohort of healthy older adults.
• To examine the relationship between episodic learning rate and grey matter volume and white matter microstructure.
• To explore potential sex differences in episodic learning rate.

Main Methods:

• Utilized voxel-based morphometry to assess grey matter (GM) volume.
• Employed tract-based spatial statistics to analyze white matter (WM) microstructure (fractional anisotropy and mean diffusivity).
• Analyzed data from 982 cognitively healthy older participants from the Vallecas Project cohort.

Main Results:

• Episodic learning rate was faster in women and negatively associated with age.
• Hippocampal and anterior thalamic GM volume positively correlated with learning rate.
• Learning rate was associated with WM microstructure integrity in tracts including the anterior thalamic radiation and fornix.

Conclusions:

• Episodic learning rate in older adults is associated with specific brain anatomical structures, including grey matter volume and white matter microstructure.
• Findings highlight the importance of studying learning processes, not just retrieval, in cognitive aging.
• Further research is warranted to explore the diagnostic potential of episodic learning rate in aging populations.