Is Rest Really Rest? Resting-State Functional Connectivity During Rest and Motor Task Paradigms

Area of Science:

• Neuroscience
• Cognitive Neuroscience
• Neuroimaging

Background:

• Large-scale brain networks are identified during wakeful rest, but their alteration by simple motor tasks in functional magnetic resonance imaging (fMRI) is unclear.
• Resting-state functional connectivity analysis is crucial for understanding brain function.

Purpose of the Study:

• To investigate the influence of simple motor tasks on resting-state functional connectivity using fMRI.
• To compare resting-state functional connectivity during a standard resting-state paradigm with that derived from motor task data residuals.

Main Methods:

• Blood-oxygen-level-dependent (BOLD) fMRI was used in healthy subjects.
• Seed-voxel analysis defined the default mode network, executive control network (ECN), and sensorimotor, auditory, and visual networks.
• Resting-state analysis was performed on both standard resting-state data and residual time courses after motor task regression.

Main Results:

• Resting-state analysis of residual motor task data showed reduced functional connectivity within the motor network.
• Connectivity between the insula and the ECN was reduced in the residual data compared to standard resting-state data.
• Overall, simple motor tasks had minimal impact on resting-state functional connectivity, particularly in non-motor areas.

Conclusions:

• Simple self-directed motor tasks minimally alter whole-brain resting-state functional connectivity.
• Previously acquired fMRI studies using simple block-design motor tasks may be retrospectively analyzed for resting-state connectivity assessments.