Age-related differences in prefrontal-hippocampal connectivity are associated with reduced spatial context memory

Area of Science:

• Neuroscience
• Cognitive Neuroscience
• Neuroimaging

Background:

• Episodic memory, particularly spatial context memory, declines with age.
• Altered functional connectivity in brain networks, including the dorsolateral prefrontal cortex (DLPFC) and hippocampus (HC), is implicated in age-related memory deficits.

Purpose of the Study:

• To investigate age-related differences in functional brain connectivity during spatial context memory tasks.
• To examine the relationship between seed connectivity patterns in the DLPFC and HC and memory performance across the adult lifespan.

Main Methods:

• Functional magnetic resonance imaging (fMRI) was employed in an adult lifespan sample.
• Seed connectivity analysis was used to assess correlations in brain activity between seed regions (DLPFC and HC) and the rest of the brain during encoding and retrieval phases.
• Performance on a spatial context memory task was correlated with connectivity measures.

Main Results:

• In young adults, positive connectivity between the right DLPFC and frontal, parietal, and visual cortical regions during encoding, and positive connectivity with these regions along with negative connectivity with the posterior HC during retrieval, correlated positively with memory performance.
• In older adults, positive connectivity between the right DLPFC and the same brain regions, including the posterior HC, was observed during both encoding and retrieval.
• This pattern of connectivity in older adults was negatively correlated with retrieval accuracy.

Conclusions:

• Age-related differences in spatial context memory performance are associated with altered functional connectivity patterns between frontal-parietal and visual cortical regions and the posterior hippocampus.
• The findings suggest that changes in brain network interactions with aging contribute to memory decline.