Gait Speed and Gait Variability Are Associated with Different Functional Brain Networks

Figures

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  FIGURE 1. Resting-state functional connectivity of the frontoparietal control network. The standard map (A) of the frontoparietal control network derived from a large sample of healthy adults (Yeo et al., 2011) was used as a functional seed to determine the strength of functional connectivity within this network of the older adults with slow gait and executive dysfunction (B). Warmer colors indicate stronger connectivity. The black outlined region represents the region selected for visualization of the voxel-wise analysis depicted in Figures 4A,B.

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  FIGURE 2. Resting-state functional connectivity between dorsal attention network and default network. The standard maps (A) of the dorsal attention network (green) and the default network (red) derived from a large sample of healthy young adults (Yeo et al., 2011) were used as functional seeds to determine the strength of functional connectivity between these networks of the older adults with slow gait and executive dysfunction (B). Warmer colors represent regions with stronger in-phase functional connectivity to the default network; cooler colors represent regions with stronger anti-phase functional connectivity to the default network. The black outlined region represents the region selected for visualization of the voxel-wise analysis depicted in Figures 4C,D.

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  FIGURE 3. Gait speed (A,C) and variability (B,D) correlations with resting-state functional connectivity within cognitive networks: frontoparietal control (A,B) and default-dorsal attention (C,D). Participants who walked with greater gait speed tended to have stronger functional connectivity within the frontoparietal control network (A). Those who exhibited less stride time variability tended to have stronger functional connectivity between the dorsal attention network and the default network (greater negative values reflect stronger anti-phase connectivity, D). No other correlations between walking metrics and resting-state network connectivity reached significance (B,C; all other correlations not pictured).

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  FIGURE 4. Voxel-wise analysis of within-network (A,B) and between-network (C,D) correlation of functional connectivity with gait speed (A,C) or gait variability (B,D). In each panel, warmer colors represent voxels whose strength of functional connectivity correlated with gait speed or variability, when seeding either the frontoparietal control network (A,B) or the default network (C,D). Black outlines indicate the within-network regions of the frontoparietal control network (A,B) or dorsal attention network (C,D). Within frontoparietal control network, voxelwise functional connectivity is more strongly associated with gait speed (A) than gait variability (B). In contrast, between-network functional connectivity from the default network to the dorsal attention network (black outline) is less strongly associated with gait speed (C) but more strongly associated with gait variability (D).