How do tasks impact the reliability of fMRI functional connectivity?

Area of Science:

• Neuroimaging
• Cognitive Neuroscience
• Biomarker Research

Background:

• Functional magnetic resonance imaging-functional connectivity (fMRI-FC) shows promise for biomarker research.
• Low measurement reliability in conventional fMRI-FC acquisitions can hinder its application.
• Scan length, head motion, signal properties (tSNR), and task state influence FC reliability.

Purpose of the Study:

• To investigate the regional effects of tasks on fMRI-FC reliability.
• To examine how BOLD signal properties (tMean, tSD) influence tSNR and FC reliability.
• To understand task-specific modulations of signal properties and their impact on FC reliability.

Main Methods:

• Utilized the Midnight Scan Club (MSC) dataset with 5 hours of resting-state and 6 hours of task fMRI data from 10 healthy adults.
• Analyzed regional variations in FC reliability and BOLD signal properties (tMean, tSD) during rest and task conditions.
• Correlated signal variability with FC reliability across different brain regions and acquisition states.

Main Results:

• Tasks enhanced FC reliability and increased temporal standard deviation (tSD) in task-engaged regions compared to rest.
• FC signal variability and reliability were generally reduced in regions outside of task engagement during tasks.
• Signal variability emerged as the strongest predictor of FC reliability across the brain.

Conclusions:

• Task selection significantly impacts fMRI-FC reliability, influencing specific brain networks.
• Optimizing task design is crucial for maximizing FC reliability in targeted neural systems.
• Understanding regional task effects on signal variability is key for reliable fMRI-FC biomarker development.