Genetic control of dynamic brain network reconfiguration during working memory.

Area of Science:

• Neuroscience
• Cognitive Neuroscience
• Behavioral Genetics

Background:

• Working memory is crucial for cognition.
• Genetic underpinnings of dynamic brain network states during cognitive tasks are not well understood.

Purpose of the Study:

• To investigate the heritability of static and dynamic functional connectivity during a working memory task.
• To identify genetic contributions to cognitive-load-specific neural processes.

Main Methods:

• Examined monozygotic (MZ) and dizygotic (DZ) twins performing a 2-back vs. 0-back task.
• Analyzed static and dynamic functional connectivity, including mean and variance components.
• Utilized k-means clustering to identify recurring brain states.

Main Results:

• Static functional connectivity showed moderate heritability (approx. 0.30), particularly in association cortices.
• Dynamic connectivity variance exhibited the strongest genetic influence (approx. 0.25-0.44), indicating heritable neural flexibility.
• Neither state occupancy nor switching dynamics were significantly heritable, suggesting environmental influences.

Conclusions:

• Genetic influence on brain networks during working memory follows a gradient: static connectivity is trait-like, mean dynamic connectivity is task-modulated, and dynamic variability is highly heritable.
• Neural flexibility, reflected in dynamic connectivity variability, is a key heritable phenotype.
• Dynamic connectivity variability may serve as a sensitive endophenotype for cognitive and psychiatric traits.