Figure 1.
Location of seed ROIs adopted in the present study.
Location of seed ROIs for Broca's (A) and Wernicke's areas (B) in comparison to the regions in AAL and BA templates.
Figure 2.
Consistency of functional connectivity strength of Broca's area in both short-term and long-term.
Scatter plots of whole brain RSFC strength for Broca's area between Scan 2 and Scan3 (short-term) (A), and between Scan 1 and average of Scans 2 and 3 (long-term) (B), each dot in the graph represents a 3×3×3 mm3 voxel. Both of these two correlation coefficients are larger than 0.9, it revealed great consistency of FC strength in short-term and long-term.
Figure 3.
Test-retest reliability of language network.
Short-term reliability maps (Z maps and ICC maps) for resting-state language network seeding at Broca's (A, E) and Wernicke's areas (B, F), and long-term reliability maps (Z maps and ICC maps) for resting-state language network seeding at Broca's (C, G) and Wernicke's areas (D, H). Only regions with high reliability are depicted (voxel level p<0.005, voxel size > = 200, corresponding to corrected pFWE <0.05). L and R represent left hemisphere and right hemisphere, respectively.
Figure 4.
Relationship between short-term and long-term reliability of language network.
Scatter plots between short- and long-term reliability among whole brain resting-state language network seeding at Broca's area (A) and Wernicke's area (B). Each dot in the graph represents a 3×3×3 mm3 voxel. Both of these two correlation coefficient are larger than 0.65, indicating short-term and long-term reliability are significantly correlated.
Table 1.
Regions that showed high Intra- and inter-session reliability of functional connectivity with Broca's and Wernicke's area.
Figure 5.
Functional lateralization of language network.
Hemispheric asymmetry of functional connectivity patterns of Broca's area (A) and Wernicke's area (B). L and R represent left hemisphere and right hemisphere, respectively. The foci in the left hemisphere show significant asymmetric functional connectivity with their ipsilateral seeds, and the foci in the right hemisphere show significant asymmetric functional connectivity with their contralateral seeds. Results were statistically corrected (voxel level p<0.005, voxel size > = 200, corresponding to corrected pFWE <0.05).
Table 2.
Cortical regions revealed significant functional lateralization with Broca's and Wernicke's areas.
Figure 6.
Average connectivity strength in the regions with significant functional hemispheric asymmetry of Broca's area.
Red color denotes connectivity strength computed using left Broca's area as seed; blue color denotes connectivity strength computed using right Broca's area as seed. Prefix: l-left, r-right, b-bilateral. Abbreviation: ITG-inferior temporal gyrus, MTG-meddle temporal gyrus, IPG-inferior parietal gyrus, SPG-superior parietal gyrus.
Figure 7.
Average connectivity strength in the regions with significant functional hemispheric asymmetry of Wernicke's area.
Red color denotes connectivity strength computed using left Wernicke's area as seed; blue color denotes connectivity strength computed using right Wernicke's area as seed. Prefix: l-left, r-right, b-bilateral. Abbreviation: MFG-middle frontal gyrus, SFG-superior frontal gyrus, SMA-supplemental motor area, SMG-supramarginal gyrus, STG-superior temporal gyrus, AG-angluar gyrus, MOG-middle occipital gyrus.
Figure 8.
Test-retest reliability of functional lateralization of language network.
TRT reliability of functional asymmetry (Z maps and ICC maps) of both Broca's (A, C, E, G) and Wernicke's (B, D, F, H) areas. Both intra-session (A, B, E, F) reliability and inter-session (C, D, G, H) reliability areas shown. Only regions with high reliability are depicted (voxel level p<0.005, voxel size > = 200, corrected pFWE <0.05). L and R represent left and right hemispheres, respectively.
Table 3.
Cortical regions revealed significant test-retest reliability of functional lateralization
Figure 9.
The impact of GSR on TRT reliability of language network.
Comparison of ICC maps of RSFC of Broca's area between with (C, D) and without (A, B) global signal regression. Z-transformed intra-class correlation coefficient (ICC) is used to assess TRT reliability. Only regions with high reliability are depicted (voxel level p<0.005, voxel size > = 200, corresponding to corrected corresponding to corrected pFWE <0.05. L and R represent left and right hemispheres, respectively.
Figure 10.
The histograms of ICC values across the whole brain voxels with (B) and without (A) GSR.
Figure 11.
Relationship between ICC values of two regression conditions.
Scatter plots of whole brain RSFC inter-session ICC values between with and without global signal regression. Both Broca's (A) and Wernicke's areas (B) are depicted. Each dot in the graph represents a 3×3×3 mm3 voxel. Both of these two correlation coefficient are larger than 0.8. It reveals high correlation of temporal reliability no matter the global signal was regressed or not.