White matter integrity in brain structures supporting semantic processing is associated with value-directed...

Area of Science:

• Neuroscience
• Cognitive Aging
• Neuroimaging

Background:

• White matter microstructure undergoes significant changes with aging.
• Understanding how white matter integrity supports learning, especially of rewarding information, is crucial for cognitive health in older adults.

Purpose of the Study:

• To investigate the relationship between white matter microstructure integrity and the selective learning of high-value material in healthy older adults.

Main Methods:

• Employed diffusion tensor imaging (DTI) to measure white matter structure.
• Utilized a value-directed remembering task with free recall of word lists, where item value was indicated by preceding cues.

Main Results:

• Higher structural integrity in the left inferior fronto-occipital fasciculus correlated with better recall of high-value items.
• No significant correlation was found between memory for high-value items and the uncinate fasciculus or the nucleus accumbens-ventral tegmental area reward pathway in older adults.

Conclusions:

• White matter integrity in specific tracts, like the left inferior fronto-occipital fasciculus, is vital for older adults to encode and recall high-value information.
• Unlike younger adults, older adults' value-based memory modulation relies more on semantic processing circuits, suggesting distinct aging mechanisms.