Brain-breathing interaction during MRI-related anxiety

Area of Science:

• Neuroscience
• Psychophysiology
• Computational Neuroscience

Background:

• Nasal breathing influences neural oscillations in the prefrontal cortex and limbic systems.
• Functional magnetic resonance imaging (fMRI) allows non-invasive study of amygdala and hippocampus activity.
• Previous research links neural oscillations with cardiac and respiratory rhythms.

Purpose of the Study:

• To investigate the directed coupling between brain structures and bodily organs using simultaneous physiological and fMRI recordings.
• To test Klimesch's binary hierarchy model predicting preferred breathing frequencies and infra-slow oscillations (ISO).
• To identify breathing patterns associated with anxiety during neuroimaging.

Main Methods:

• Simultaneous recording of BOLD signals, respiration, and cardiac RR interval (RRI) time courses during fMRI.
• Application of a multivariate autoregressive (MVAR) model and Granger causality analysis to assess information flow.
• Analysis of neural oscillations in gamma, beta, and infra-slow ranges (<0.1 Hz).

Main Results:

• Nasal breathing entrains fast oscillations in the prefrontal cortex and limbic systems.
• The study identified preferred breathing frequencies of 0.32 Hz, 0.16 Hz, and 0.08 Hz, and an ISO at 0.02 Hz.
• A breathing frequency of 0.32 Hz (∼20 breaths/min) was found to be a universal marker of anxiety in patients and healthy participants.

Conclusions:

• Simultaneous physiological and fMRI recordings with MVAR modeling can reveal brain-body information flow.
• Klimesch's model accurately predicts preferred breathing frequencies linked to neural and physiological rhythms.
• The 0.32 Hz breathing frequency is a significant psychophysiological marker for anxiety, observable during fMRI.