Exploring small-world brain connectivity in aging and its relationship with cognitive reserve

Area of Science:

• Neuroscience
• Cognitive Aging Research
• Brain Network Analysis

Background:

• The aging brain is vulnerable, necessitating strategies for cognitive function and independence.
• Cognitive reserve (CR) is a key mechanism for resilience against age-related cognitive decline.
• Understanding brain network organization may reveal how CR supports cognitive health.

Purpose of the Study:

• To explore if age- and CR-related differences are reflected in large-scale brain network organization.
• To examine electroencephalographic (EEG) connectivity metrics in relation to cognitive reserve and aging.

Main Methods:

• Investigated resilience by relating cognitive reserve (CR), measured by the Cognitive Reserve Index (CRI), to brain network topology.
• Quantified network topology using the Small-World (SW) index from resting-state EEG recordings across multiple frequency bands.
• Compared SW index between age groups and within the elderly group based on CRI levels.

Main Results:

• Adults showed higher SW values in Delta and Theta bands, and lower SW in Alpha 2 compared to the elderly.
• Within the elderly group, higher CRI correlated with greater SW values in Delta, Beta 2, and Gamma bands.
• Higher CRI in the elderly was also associated with marginally significant lower SW values in the Alpha 2 band.

Conclusions:

• Similar cognitive scores (MMSE) suggest observed brain network differences may reflect compensatory mechanisms.
• Findings provide indirect evidence that individual differences in CR are linked to distinct brain network organization in healthy aging.
• Large-scale neural network dynamics may serve as markers of adaptive brain functioning in later life.