DTI fiber tracts from a representative participant.

<p>Fiber pathways between: (A) PCC (R1) and mPFC (R2), (B) PCC (R1) and LMTC (R3), and (C) PCC (R1) and LAG (R4).</p

Time-varying nature of power in 6 sample participants.

<p>Slow-4 frequency band activity fluctuates significantly (A–F). Overall, there is a significant power variation across different time windows, each of size 38 sec in the slow-4 band (0.0027–0.073 Hz) for 11 out of 17 participants.</p

Wavelet power and in-out causal flow.

<p>Power at slow-5 frequency (left column) and in-out flow at slow-4 frequency (right column) for regions: (A) PCC, (B) mPFC, (C) LMTC, (D) LAG. Dotted boxes are used to highlight that the higher values of power and the in-out flow originate at around the same time points but at different frequencies as for the pair (slow-4 power, slow-3 net causal flow) as shown in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0064466#pone-0064466-g004" target="_blank">figure 4</a>.</p

Wavelet power and in-out causal flow.

<p>Power at slow-4 frequency (left column) and in-out flow at slow-3 frequency (right column) for regions: (A) PCC, (B) mPFC, (C) LMTC, (D) LAG. Dotted boxes are used to highlight that the higher values of power and the in-out flow originate at around the same time points but at different frequencies.</p

Spectral peaks of causal flow and related power at lower frequencies.

<p>(A) In-out flow at slow-4 and power at slow-5, and (B) in-out flow at slow-3 and power at slow-4. Units of power and in-out flow are arbitrary but normalized to same scale.</p

Structure-function relation.

<p>The maximum in-flow and number of fibers for all the regions have been plotted: (A) the maximum in-flow at slow-3 (blue bars) averaged over all participants for each region and corresponding number of fibers (red bars) averaged over all participants for the corresponding regions, and (B) a positive significant linear relation between the in-out flow at slow-3 and the number of fibers connecting all four regions in 6 participants who underwent both DTI and fMRI scanning.</p

Voxel-averaged time-series for four brain regions and correlation coefficients between pairs.

<p>(A) Times-series averaged over all the trials for four nodes, and (B) positive significant correlation coefficients (c) were found to be significantly varying from one window to next.</p

Time-frequency power spectra from a representative participant.

<p>For regions: (A) PCC, (B) mPFC, (C) LMTC, and (D) LAG, the white dotted lines marked the region for fluctuations for frequencies at slow-4.</p

Linear relationship of the net in-out flow with power for all four nodes.

<p>(A) Slow-4 causal flow is related with the power at slow-5, (B) slow-3 causal flow is related with power at slow-4.</p