Structural and functional differences in medial prefrontal cortex underlie distractibility and suppression deficits...

Area of Science:

• Neuroscience
• Cognitive Aging
• Neuroimaging

Background:

• Older adults exhibit working memory (WM) deficits, worsened by distractors.
• Reduced suppression of visual cortical activity to irrelevant stimuli is observed in aging.
• Top-down control deficits from the prefrontal cortex are hypothesized but not directly shown.

Purpose of the Study:

• To investigate the neural basis of distraction's impact on WM in older adults.
• To examine age-related impairments in neural suppression.
• To explore the role of prefrontal cortex connectivity in these deficits.

Main Methods:

• Structural and functional MRI scans were performed on older adults.
• Participants completed tasks involving memory for relevant visual stimuli amidst distractors.
• Analysis focused on functional connectivity and cortical volume.

Main Results:

• Confirmed age-related deficits in WM and neural suppression.
• Identified altered functional connectivity between visual cortices and the medial prefrontal cortex (mPFC).
• Found associations between WM distractibility, neural suppression, and mPFC structure/activity in older adults.

Conclusions:

• Aging impairs working memory and neural suppression, linked to mPFC dysfunction.
• Medial prefrontal cortex connectivity and integrity are crucial for resisting distraction in older age.
• Individual differences in mPFC structure and function predict working memory performance in older adults.