A guide to peripheral physiology measurement using the BrainAmp ExG MR – Part 3: Sensor tutorial, a new chapter for correct use in the MR environment

Dr. Stefania Geraci (Brain Products Team Leader of Technical Support)
and Cilia Jäger, Ph.D. (Brain Products Application Specialist EEG-fMRI)

Peripheral physiology can add valuable information to fMRI and EEG signal analyses. Whether the goal is to rule out the contribution of physiological noise to the neural signal or to understand how physiological responses correlate with neural activity, our sensors facilitate measuring the coupling between the brain, physiological signals, and behavior. For example, fluctuations in the autonomic nervous system correlate with both fluctuations in the BOLD signal and oscillatory EEG activity (Yuan et al 2013, Iacovella 2011, Rassi et al. 2019; Sihn and Kim 2022). Physiological measures such as galvanic skin response (GSR) or changes in respiration rate can be used to easily identify levels of arousal and changes within the autonomic nervous system.

They can also be used to identify the neural and non-neuronal components of the BOLD signal by measuring the level of physiological noise that contributes to the BOLD signaling including cardiac and respiratory sources. Our scalable BrainAmp MR system allows peripheral physiology measurements to be incorporated easily with EEG recordings in BrainVision Recorder with the addition of a BrainAmp ExG MR. In addition, the SyncBox ensures simultaneous recording of BOLD, EEG, and peripheral physiology measurements, which allows for direct comparison between all three signal types.

Our Application Specialist EEG-fMRI, Cilia Jäger, PhD, and Dr. Stefania Geraci, a member of the Technical Support team, present here, as the third chapter of our series of support tips, the new section of the well-known Sensor Tutorial: the “MR Sensors”. This section of the tutorial will guide you through the correct and safe use of the most commonly used sensors for peripheral physiology measurements in MR scanners with static field strength up to 3 Tesla.

MR Sensors Tutorial

Dedicated sub-chapters describe the use of the following sensors:

  • The GSR MR sensor for the measurement of electrodermal activity in an MR environment

  • The Respiration sensor MR to measure thoracic or abdominal respiratory movements

If you need further help on sensor application or signal analysis, please feel free to contact either the Brain Products Technical Support Team or Scientific Support Team. We are happy to provide you with more information and answer all remaining questions you may have.

References

Iacovella V, Hasson U.
The relationship between BOLD signal and autonomic nervous system functions: implications for processing of “physiological noise”.
Magn Reson Imaging. 2011 Dec;29(10):1338-45. doi: 10.1016/j.mri.2011.03.006. Epub 2011 May 2. PMID: 21543181.

Rassi E, Dorffner G, Gruber W, Schabus M, Klimesch W.
Coupling and Decoupling between Brain and Body Oscillations.
Neurosci Lett. 2019 Oct 15;711:134401. doi: 10.1016/j.neulet.2019.134401. Epub 2019 Jul 23. PMID: 31349018.

Sihn D, Kim SP.
Brain Infraslow Activity Correlates With Arousal Levels.
Front Neurosci. 2022 Feb 25;16:765585. doi: 10.3389/fnins.2022.765585. PMID: 35281492; PMCID: PMC8914100.

Yuan H, Zotev V, Phillips R, Bodurka J.
Correlated slow fluctuations in respiration, EEG, and BOLD fMRI.
Neuroimage. 2013 Oct 1;79:81-93. doi: 10.1016/j.neuroimage.2013.04.068. Epub 2013 Apr 28. PMID: 23631982.