Robustness of intrinsic connectivity networks in the XXXX brain to the presence of acoustic scanner noise.

@entity1 @entity4365 @entity2734
Evoked responses in functional magnetic resonance imaging (fMRI) are affected by the presence of acoustic scanner noise ( @entity2734 ). Particularly, stimulus-related activation of the auditory system and deactivation of the default mode network have repeatedly been shown to diminish. In contrast, little is known about the influence of @entity2734 on the spontaneous fluctuations in brain activity that are crucial for network-related neuroimaging methods like independent component analysis (ICA) or functional and effective connectivity analysis (ECA). The present study assessed the robustness of intrinsic connectivity networks in the @entity1 brain to the presence of @entity2734 by comparing 'silent' (sparse) and 'noisy' (continuous) acquisition schemes, both during task performance and during rest. In agreement with existing literature, @entity2734 strongly diminished conventional evoked response levels. In contrast, ICA and ECA robustly identified similar functional networks regardless of the scanning method. @entity2734 affected the strength of only few independent components, and effective connectivity was hardly sensitive to @entity2734 overall. However, unexpectedly, ICA revealed notable differences in the underlying neurodynamics. In particular, @entity4365 dominated in the commonly used continuous scanning environment, but signal spectra were significantly flatter during the less noisy sparse scanning runs. We tentatively attribute these differences to the ubiquitous influence of @entity2734 on alertness and arousal.
