Article Figures & Data
Figures
- Figure 1.
LA and FC during resting-state CLOSED (left) and OPEN (right) conditions. A, SPMs of whole-brain voxelwise one sample t tests for FDG uptake controlling for each subject's grand mean signal. B, SPMs of whole-brain voxelwise one-sample t tests on individual FC maps revealing rs-FC for seed ROI V1 (V1-FC). Regions (red) with V1-FC during the CLOSED condition include primary and secondary visual cortex, and inferior parietal and temporoparietal areas. Additional regions with V1-FC during the OPEN condition include cingulate, insular, and prefrontal cortices; brainstem; thalamus; and cerebellum. C, SPMs of whole-brain voxelwise one sample t tests on individual FC maps revealing rs-FC for averaged seed ROI of the SAL network (SAL-FC). Regions (red) with SAL-FC during the CLOSED condition include cingulate, insular, superior parietal, and prefrontal cortices; brainstem; thalamus; and cerebellum. Additional regions with SAL-FC during the OPEN condition included primary and secondary visual, and anterior cingulate cortices. All SPMs are thresholded at an FWE-corrected p value of <0.05 and are superimposed on a high-resolution T1-weighted anatomical image. x, z, Coordinates of brain slices in MNI space; R, right side of the brain.
- Figure 2.
Quantitative relationship between LA and FC in the resting human brain. A, SPMs of whole-brain voxelwise ANCOVA for LA changes controlling for each subject's grand mean signal. Regions (cyan) with increased LA during the OPEN condition included V1, aI, aCC, and mCC. FWE corrected, p < 0.05. R, Right. B, SPMs of whole-brain voxelwise independent-samples t tests on individual FC maps for seed ROIs (cyan) V1 (V1-FC; top row) and SAL hubs (SAL-FC; bottom row) revealing FC changes. Regions (yellow) with increased V1-FC during the OPEN condition include SAL hubs, thalamus, brainstem, and cerebellum; the main region with increased SAL-FC during the OPEN condition was V1 and parts of aCC. p < 0.05, FWE corrected. C, Voxelwise conjunction showing regions (violet) with increased LA and FC. An exemplary distribution of voxel values of LA (y-axis) and V1-FC (x-axis) of aI taken from the first subject is shown on the right side. To quantify the relationship between LA and FA, we calculated the SpaSi[LA, FC] ROI coefficient for each subject and each ROI as the voxelwise spatial correlation between normalized LA and between-network FC values, and subsequently analyzed them in a two-way ANOVA. D, Post hoc independent-samples t tests revealed significantly increased SpaSiOPEN for ROIs V1, aCC, and aI. **p < 0.005, ***p < 0.0005. Error bars denote 5th and 95th percentiles. No difference occurred in V1 for within-network connectivity (V1[V1-FC]) and in mCC for between-network FC. E, Mean square of SpaSiCLOSED and SpaSiOPEN, indicating the voxelwise variability of FC explained by LA. *p < 0.05, ***p < 0.0005, one-sample t tests performed separately for SpaSiCLOSED and SpaSiOPEN. Cluster coordinates for all SPMs and cluster sizes for conjunction regions can be found in Table 1.
Tables
- Table 1.
Brain regions with increased LA, increased FC, and overlapping increases in LA and FC
Region Center of mass (x, y, z coordinates in MNI space) PET statistics fMRI statistics Cluster size overlap (voxels) V1 seed SAL seed Occipital cortex: calcarine, lingual, fusiform gyrus 15, −74, 7 14.75 181 −15, −99, 9 4.57 9, −81, 9 4.82 Extrastriate cortex −41, −81, 19 10.19 Cuneus 18, −79, 31 8.58 mCC 0, −31, 37 11.81 212 −3, −21, 36 5.44 Left insula −39, −13, 13 11.13 Left aI −51, 11, 7 8.85 211 −42, 15, −3 7.03 Left inferior frontal gyrus −48, 29, −2 8.84 Left superior frontal gyrus −30, 66, 6 5.89 Right superior frontal gyrus 24, 63, −6 6.81 Middle superior frontal gyrus −6, 50, 37 10.6 aCC −6, 20, 37 8.78 212 0, 21, 30 8.55 0, 27, 21 5.27 Medial subgenual frontal gyrus −6, 20, −20 8.68 Right aI 36, 14, 4 8.64 284 51, 21, −6 6.22 Fusiform/inferior temporal gyrus 36, −10, −38 7.94 Thalamus −3, −24, 6 5.71 Cerebellum 36, −54, −27 8.55 Brainstem −3, −21, −18 6.42 Data are t statistics, unless otherwise indicated. Bold indicates overlapping increases in LA and FC. See also Figure 1 and main text.
