Lifespan oscillatory dynamics in lexical production: A population-based MEG resting-state analysis

Area of Science:

• Neuroscience
• Cognitive Psychology
• Aging Research

Background:

• Lexical production relies on cognitive control, which changes with age.
• The interplay between domain-general and language-specific cognitive functions is crucial for semantic access.
• Neurocognitive models implicate the Default Mode Network (DMN) and Fronto-Parietal Network (FPN) in age-related cognitive changes.

Purpose of the Study:

• To clarify the time-varying architecture of Default Mode Network (DMN) and Fronto-Parietal Network (FPN) connectivity in aging.
• To investigate how neural dynamics shift to support lexical production across the adult lifespan.
• To understand the compensatory mechanisms in the aging brain for maintaining word-finding abilities.

Main Methods:

• Utilized magnetoencephalography (MEG) resting-state data from a population-based sample (CamCAN) of healthy adults aged 18-88 years.
• Analyzed dynamic functional connectivity between the DMN and FPN.
• Examined changes in neural oscillations, particularly alpha-band activity.

Main Results:

• Observed a shift in DMN-FPN dynamics from anterior-ventral to posterior-dorsal states until midlife.
• This neural dynamic shift was associated with heightened alpha-band oscillations.
• Sensorimotor integration along the posterior pathway facilitated neural cross-talk as anterior cognitive states became compromised.

Conclusions:

• The aging brain employs a bottom-up, exploitation-based cognitive control strategy to preserve lexical production.
• A pivotal shift in neural network dynamics around midlife helps mitigate word-finding challenges.
• Maintaining lexical production involves a complex interplay between abstraction, cognitive control, and perceptive-motor systems.