Changes in Cortical Activity during Preferred and Fast Speed Walking under Single- and Dual-Tasks in the Young-Old and Old-Old Elderly

Figures

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  Figure 1. Position of functional near-infrared spectroscopy (fNIRS) measurement optodes and channels. In the fNIRS channel arrangement, 22 sources and 21 detectors covered the cortical areas of the bilateral M1-leg, PM, SMA, S1, PPC, dlPFC, and vmPFC using 71 channels of interest. LPA, left pre-auricular points; RPA, right pre-auricular points; Nz, nasion; Iz, inion; M1-leg, primary leg motor cortex; PM, premotor area; SMA, supplementary motor area; S1, primary somatosensory cortex; PPC, posterior parietal cortex; dlPFC, dorsolateral prefrontal cortex; vmPFC, ventromedial prefrontal cortex.

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  Figure 2. Cortical activation patterns during walking in the young-old and the old-old. Cortical activities measured by oxyHb concentration were increased during dual-task walking compared with single-task walking but decreased during fast-walking speed compared with self-selected walking speed in the bilateral M1-leg, SMA, and dlPFC in both the young-old and the old-old elderly. ST, single-task; DT, dual-task; SSWS, self-selected walking speed; FWS, fast walking speed.

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  Figure 3. Changes in integral values of oxyHb concentration during walking in the young-old and the old-old. In the young-old, oxyHb significantly increased in the right PM, left S1, and bilateral PPC at both self-selected walking speed (A) and fast walking speed (except left PPC) (B) during the dual-task walking compared with the single-task. However, there was no change in the old-old elderly. In addition, oxyHb concentration in the bilateral PPC was significantly lower in the old-old elderly compared with the young-old during the dual-task walking. oxyHb, oxyhemoglobin; PM, pre-motor area; S1, primary somatosensory motor cortex; PPC, posterior parietal cortex; ST, single-task; DT, dual-task; Rt., right; Lt., left.

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  Figure 4. Association between age and regional oxyHb values during dual-task walking. The black circle represents self-selected walking speed (SSWS), and the gray square represents fast walking speed (FWS). In the SSWS, the integral value of oxyHb in the right PPC was negatively associated with age. There was no significant correlation in other ROIs such as the right PM, left S1, or left PPC. oxyHb, oxyhemoglobin; PM, pre-motor area; S1, primary somatosensory motor cortex; PPC, posterior parietal cortex; Rt., right; Lt., left.