Task-dependent reorganization of functional connectivity networks during visual semantic decision making

Area of Science:

• Neuroscience
• Cognitive Neuroscience
• Network Science

Background:

• Functional MRI (fMRI) is crucial for studying brain activity during tasks and at rest.
• Understanding task-related functional connectivity is vital, but prior studies present conflicting findings.
• Dynamic connectivity offers a potential new metric for neural network robustness.

Purpose of the Study:

• To investigate task-related changes in functional connectivity networks using fMRI.
• To compare functional connectivity during a semantic decision task versus resting state in healthy subjects.
• To explore the relationship between task-based and resting-state brain networks.

Main Methods:

• Utilized a graph theory-based network approach.
• Analyzed fMRI data from 21 healthy, right-handed participants.
• Compared functional connectivity during resting state versus a semantic decision task.

Main Results:

• Resting state showed three distinct functional modules.
• A language-related module emerged during the semantic decision task.
• Task performance increased within-module connectivity in default mode and language areas, while rest showed greater diffuse between-module connectivity.

Conclusions:

• Network topology significantly differs between resting and task states.
• Semantic decision making involves increased connectivity within default mode and language networks.
• Task engagement reduces distributed connectivity through default mode network hubs.