Prevalent and sex-biased breathing patterns modify functional connectivity MRI in young adults

Charles J Lynch,Alex Martin,Benjamin M Silver,Marc J Dubin,Henning U Voss,Rebecca M Jones,Jonathan D Power

doi:10.1038/s41467-020-18974-9

Abstract

Resting state functional connectivity magnetic resonance imaging (fMRI) is a tool for investigating human brain organization. Here we identify, visually and algorithmically, two prevalent influences on fMRI signals during 440 h of resting state scans in 440 healthy young adults, both caused by deviations from normal breathing which we term deep breaths and bursts. The two respiratory patterns have distinct influences on fMRI signals and signal covariance, distinct timescales, distinct cardiovascular correlates, and distinct tendencies to manifest by sex. Deep breaths are not sex-biased. Bursts, which are serial taperings of respiratory depth typically spanning minutes at a time, are more common in males. Bursts share features of chemoreflex-driven clinical breathing patterns that also occur primarily in males, with notable neurological, psychiatric, medical, and lifespan associations. These results identify common breathing patterns in healthy young adults with distinct influences on functional connectivity and an ability to differentially influence resting state fMRI studies.

Highlights

Resting state functional connectivity magnetic resonance imaging is a tool for investigating human brain organization
Breathing modifies the concentration of carbon dioxide in arterial blood, which is a potent modulator of cerebral blood flow, and the functional connectivity magnetic resonance imaging (fMRI) signal[6,7]
Little is known about the breathing characteristics of healthy young adults lying at rest in an MRI scanner, the kind of subject that forms the backbone of the functional connectivity literature, despite the potential for breathing to systematically influence fMRI signals

Summary

Introduction

Resting state functional connectivity magnetic resonance imaging (fMRI) is a tool for investigating human brain organization. Bursts share features of chemoreflex-driven clinical breathing patterns that occur primarily in males, with notable neurological, psychiatric, medical, and lifespan associations These results identify common breathing patterns in healthy young adults with distinct influences on functional connectivity and an ability to differentially influence resting state fMRI studies. Little is known about the breathing characteristics of healthy young adults lying at rest in an MRI scanner, the kind of subject that forms the backbone of the functional connectivity literature, despite the potential for breathing to systematically influence fMRI signals To address this issue, we jointly examined respiration and fMRI signals in a large, publicly available data set of healthy young adults with large amounts of scan time per subject, the Young Adult release of the Human Connectome Project (HCP). Such quantities of data stand in contrast to the prior fMRI literature on respiration, which usually involved small numbers of relatively short recordings[9,10,11,12]

Methods

Results

Conclusion