Respiration-entrained brain oscillations in healthy fMRI participants with high anxiety

Figures

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  Figure 1. Directed coupling strengths for the high anxiety group in the 0.2–0.4 Hz frequency band. Each box shows the strength of coupling on the vertical scale. The height of bars is proportional to the mean error. The blue color shows the flow from the signal marked below the given column to the signal marked at the left, and the red color the flow from the signal marked at left to the signal marked below. Significant differences between couplings of inflow and outflow are marked by stars (p < 0.05). Note the highly-significant flow from the middle frontal gyrus (MFG, ROI 7) to the brainstem (ROIs 93 and 103), respiration and RRI (marked by a stippled ellipse), and the significant flow from the MFG to the precentral gyrus (PCG, ROI 1) and the significant flow from RRI to respiration (marked by a stippled circles).

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  Figure 2. Examples of RRI peak (longest RR interval)-triggered breathing, RRI and BOLD waves (mean + − SE) from two subjects (panel A and B) with prominent respiration at ~ 0.32 Hz. The locations of ROIs used for BOLD recordings are indicated. Note the BOLD artefact induced by vessel motion of the basilar artery in right pons/brainstem preceding respiration, measured from a chest belt (stippled vertical line). BOLD oscillations from amygdala are marked by stippled circles.

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  Figure 3. Examples of RRI peak triggered breathing and BOLD waves from a normal subject with high fMRI-related anxiety. For further explanation see Fig. 2. The data are from the first half of recording with dominant 0.16 Hz oscillations (in the second half dominated the 0.1 Hz oscillations were prevailing) and precise waves with period s of 6.2 s in amygdala.

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  Figure 4. (A) Results of DTF analyses. In each box ffDTF as a function of consecutive eight time windows of 40 s length is shown. Blue lines: outflow from the structure marked below the box to the structure marked at the left, red lines: flow from structure marked at the left to this marked below (Modified from17). (B) Examples of RRI peak triggered breathing and BOLD waves from a normal subject with low fMRI-related anxiety. For further explanation see Fig. 2. Note, the similarity of BOLD oscillation at ~ 0.16 Hz in limbic system (marked by stippled ellipses), prefrontal cortex (ROIs 1and 7) and brainstem. (ROI 103).