How in-scanner movement impacts functional connectivity in psychiatry
Published in NeuroImage.
By Linden Parkes, Ben Flucher, Murat Yücel and Alex Fornito
A common tool for studying the brain is known as functional magnetic resonance imaging (fMRI). fMRI allows us to characterise how spatially distributed regions of the brain communicate, using a method called functional connectivity. Functional connectivity is critical in psychiatry research because it allows us to characterise dysfunction in the brain associated with mental disorder. However, functional connectivity estimated from fMRI is very sensitive to artefacts associated with participant movement inside the scanner. In this work, we evaluated the efficacy of multiple methods for removing these artefacts from fMRI data. Critically, we were the first to systematically document how the choice of correction method impacts differences in functional connectivity between healthy controls and individuals with schizophrenia.
We found that no single method completely removed motion-related artefacts. Methods including ICA-AROMA and some form of volume censoring emerged as the top performers, but ICA-AROMA was far more cost effective. Critically, we found that the direction and spatial location of differences in functional connectivity between healthy controls and individuals with schizophrenia varied noticeably as a function of correction method. These findings highlight how motion-related artefact confounds pathophysiological inference, which is a very common application of fMRI, and may explain discordant results present in the literature for many mental health disorders.
Parkes, L., Fulcher, B., Yücel, M., & Fornito, A. An evaluation of the efficacy, reliability, and sensitivity of motion correction strategies for resting-state functional MRI. NeuroImage, 171, 415-436.
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