Comparable Cerebral Oxygenation Patterns in Younger and Older Adults during Dual-Task Walking with Increasing Load
Comparable Cerebral Oxygenation Patterns in Younger and Older Adults during Dual-Task Walking with Increasing Load
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DOI：
10.3389/fnagi.2016.00240
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发表时间：
2016-10-20
影响因子：
4.8
通讯作者：
Bherer, Louis
中科院分区：
文献类型：
--
作者：
Fraser, Sarah A.;Dupuy, Olivier;Bherer, Louis
关于双任务步态的神经影像学文献清楚地表明，在行走时执行认知任务时，前额叶皮层（PFC）参与增加。然而，直接比较年轻人（YA）和老年人（OA）在双任务步行过程中的脑氧合模式的结果是混合的，目前还不清楚YA和OA如何应对步行时增加的认知负荷（困难）。这项功能性近红外（fNIRS）研究在两种不同水平的认知负荷（听觉n-back）下，在自行起搏的双任务跑步机行走过程中检查了YA和OA的脑氧合。检查准确度（%）以及氧合（HbO）和脱氧（HbR）血红蛋白的变化。对于HbO和HbR测量，评估了8个感兴趣区域（ROI）：每个半球的前、后背外侧和腹外侧PFC（aDLPFC、pDLPFC、aVLPFC、pVLPFC）。19名YA（M = 21.83岁）和14名OA（M = 66.85岁）在执行听觉1-back和2-back任务时以自选速度行走。单独行走（单电机：SM）和单独执行认知任务（单认知：SC）进行了比较，双任务行走（DT = SM + SC）。在行为数据中，参与者在最低负荷水平（1-back）比最高负荷水平（2-back; p < 0.001）更准确。总体而言，YA比OA更准确（p = 0.009），尤其是在2-back任务中（p = 0.048）。在fNIRS数据中，年轻人和老年人在A HbO（3个YA，1个OA）和Delta HbR（7个YA，8个OA）的特定ROI中均具有任务效应（SM < DT）。在控制步行速度差异后，YA和OA之间的直接比较没有显示出显著的年龄差异，但确实显示了左侧aDLPFC中HbO的难度效应（13 = 0.028）和8个ROIs中6个的HbR的显著任务效应（SM < DT）。研究结果表明，YA和OA响应类似的认知负荷的操纵时，走在自行选择的步伐在跑步机上。
The neuroimaging literature on dual-task gait clearly demonstrates increased prefrontal cortex (PFC) involvement when performing a cognitive task while walking. However, findings from direct comparisons of the cerebral oxygenation patterns of younger (YA) and older (OA) adults during dual-task walking are mixed and it is unclear how YA and OA respond to increasing cognitive load (difficulty) while walking. This functional near infra-red (fNIRS) study examined cerebral oxygenation of YA and OA during self-paced dual-task treadmill walking at two different levels of cognitive load (auditory n-back). Changes in accuracy (%) as well as oxygenated (HbO) and deoxygenated (HbR) hemoglobin were examined. For the HbO and HbR measures, eight regions of interest (ROls) were assessed: the anterior and posterior dorsolateral and ventrolateral PFC (aDLPFC, pDLPFC, aVLPFC, pVLPFC) in each hemisphere. Nineteen YA (M = 21.83 years) and 14 OA (M = 66.85 years) walked at a self-selected pace while performing auditory 1-back and 2-back tasks. Walking alone (single motor: SM) and performing the cognitive tasks alone (single cognitive: SC) were compared to dual-task walking (DT = SM + SC). In the behavioural data, participants were more accurate in the lowest level of load (1-back) compared to the highest (2-back; p < 0.001). YA were more accurate than OA overall (p = 0.009), and particularly in the 2-back task (p = 0.048). In the fNIRS data, both younger and older adults had task effects (SM < DT) in specific ROls for A HbO (three YA, one OA) and Delta HbR (seven YA, eight OA). After controlling for walk speed differences, direct comparisons between YA and OA did not reveal significant age differences, but did reveal a difficulty effect in HbO in the left aDLPFC (13 = 0.028) and significant task effects (SM < DT) in HbR for six of the eight ROls. Findings suggest that YA and OA respond similarly to manipulations of cognitive load when walking on a treadmill at a self-selected pace.