Age differences in the fronto-striato-parietal network underlying serial ordering

Area of Science:

• Neuroscience
• Cognitive Psychology
• Aging Research

Background:

• Serial ordering of thoughts and actions is fundamental for complex behaviors.
• Age-related cognitive changes can impact executive functions, including serial ordering.
• The fronto-striato-parietal network is implicated in sequential processing.

Purpose of the Study:

• To investigate age-related differences in the fronto-striato-parietal network during serial ordering.
• To examine functional connectivity (psychophysiological interaction, PPI) within this network in young and older adults.
• To correlate neural activity and connectivity with task performance.

Main Methods:

• Functional magnetic resonance imaging (fMRI) was used to study 25 young and 27 older healthy adults.
• Participants performed a digit ordering task involving reordering and recalling sequential digits versus pure recall.
• Analysis focused on activation patterns and PPI within the fronto-striato-parietal network.

Main Results:

• A fronto-striato-parietal network was identified, including prefrontal, parietal, and striatal regions.
• Young adults showed increased activation and stronger PPI between prefrontal/parietal regions and the supplementary motor area for reorder & recall vs. pure recall.
• Older adults exhibited elevated prefrontal and parietal activations but attenuated PPI, with compensatory increases in connectivity between prefrontal/parietal cortex, striatum, and supplementary motor area.

Conclusions:

• Aging is associated with altered functional connectivity within the fronto-striato-parietal network during serial ordering.
• While older adults recruit these regions more intensely, their ability to flexibly modulate network connections (PPI) is reduced.
• Compensatory mechanisms involving enhanced striatal connectivity may support serial ordering performance in older age despite decreased PPI.