White Matter fMRI Activation Cannot Be Treated as a Nuisance Regressor: Overcoming a Historical Blind Spot

Lukas A Grajauskas; Tory Frizzell; Xiaowei Song; Ryan C N D'Arcy

doi:10.3389/fnins.2019.01024

White Matter fMRI Activation Cannot Be Treated as a Nuisance Regressor: Overcoming a Historical Blind Spot

Front Neurosci. 2019 Oct 4:13:1024. doi: 10.3389/fnins.2019.01024. eCollection 2019.

Authors

Lukas A Grajauskas^{1

2

3}, Tory Frizzell^{3

4}, Xiaowei Song^{1

3}, Ryan C N D'Arcy^{1

3

4

5}

Affiliations

¹ Department of Biomedical Physiology and Kinesiology, Simon Fraser University, Burnaby, BC, Canada.
² Cumming School of Medicine, University of Calgary, Calgary, AB, Canada.
³ ImageTech Lab, Surrey Memorial Hospital, Fraser Health, Surrey, BC, Canada.
⁴ Faculty of Applied Sciences, Simon Fraser University, Burnaby, BC, Canada.
⁵ Djavad Mowafaghian Centre for Brain Health, University of British Columbia, Vancouver, BC, Canada.

Abstract

Despite past controversies, increasing evidence has led to acceptance that white matter activity is detectable using functional magnetic resonance imaging (fMRI). In spite of this, advanced analytic methods continue to be published that reinforce a historic bias against white matter activation by using it as a nuisance regressor. It is important that contemporary analyses overcome this blind spot in whole brain functional imaging, both to ensure that newly developed noise regression techniques are accurate, and to ensure that white matter, a vital and understudied part of the brain, is not ignored in functional neuroimaging studies.

Keywords: BOLD; fMRI; fMRI analysis; motion regression; white matter.