Brain activation during visual working memory correlates with behavioral mobility performance in older adults.
Brain activation during visual working memory correlates with behavioral mobility performance in older adults.
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DOI：
10.3389/fnagi.2015.00186
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发表时间：
2015
影响因子：
4.8
通讯作者：
Sekiyama K
中科院分区：
文献类型：
--
作者：
Kawagoe T;Suzuki M;Nishiguchi S;Abe N;Otsuka Y;Nakai R;Yamada M;Yoshikawa S;Sekiyama K
功能活动能力和认知功能通常会随着年龄的增长而下降。我们先前发现，在老年人中，通过计时起跑测试(TUG)测量的功能流动性与视觉编码(即位置和面孔)工作记忆(WM)的认知表现有关。这表明TUG和视觉WM之间存在共同的神经基础。为了进一步阐明这种关系，本研究旨在研究WM-活动能力关联的神经基础。根据众所周知的衰老中的神经补偿模型，我们假设，活动能力较低的参与者中，容易进行WM的“注意力”脑激活会增加。研究人员分析了32名健康的老年人的数据，包括通过功能磁共振成像(FMRI)在简单的WM任务中激活大脑，以及通过拔河和简单的步行测试来表现活动能力。WM表现与拖船显著相关，但与简单步行无关。WM过程中一些前额叶脑活动与TUG成绩呈负相关，而皮层下结构包括丘脑、壳核和小脑则呈正相关。此外，皮质下区域的激活与西医成绩显著相关，西医成绩较低的受试者激活程度较低。这些结果表明，流动性较低的老年人在简单的WM任务中使用更多的皮质(额叶)和更少的皮质下资源。到目前为止，额叶补偿被分别提出在运动和认知领域，这被认为是对其他大脑区域的功能障碍的补偿；然而，在以前的研究中，这种功能障碍并不清楚。目前的研究观察到了这样的功能障碍，如皮质下区域发现的与功能低下相关的激活退化。我们得出结论，一种常见的功能失调-代偿激活模式可能是视觉WM和功能活动之间联系的神经基础。
Functional mobility and cognitive function often decline with age. We previously found that functional mobility as measured by the Timed Up and Go Test (TUG) was associated with cognitive performance for visually-encoded (i.e., for location and face) working memory (WM) in older adults. This suggests a common neural basis between TUG and visual WM. To elucidate this relationship further, the present study aimed to examine the neural basis for the WM-mobility association. In accordance with the well-known neural compensation model in aging, we hypothesized that “attentional” brain activation for easy WM would increase in participants with lower mobility. The data from 32 healthy older adults were analyzed, including brain activation during easy WM tasks via functional Magnetic Resonance Imaging (fMRI) and mobility performance via both TUG and a simple walking test. WM performance was significantly correlated with TUG but not with simple walking. Some prefrontal brain activations during WM were negatively correlated with TUG performance, while positive correlations were found in subcortical structures including the thalamus, putamen and cerebellum. Moreover, activation of the subcortical regions was significantly correlated with WM performance, with less activation for lower WM performers. These results indicate that older adults with lower mobility used more cortical (frontal) and fewer subcortical resources for easy WM tasks. To date, the frontal compensation has been proposed separately in the motor and cognitive domains, which have been assumed to compensate for dysfunction of the other brain areas; however, such dysfunction was less clear in previous studies. The present study observed such dysfunction as degraded activation associated with lower performance, which was found in the subcortical regions. We conclude that a common dysfunction—compensation activation pattern is likely the neural basis for the association between visual WM and functional mobility.