Department of Kinesiology, Brock University, St. Catharines, Canada.
School of Kinesiology, University of British Columbia, Vancouver, Canada.
Exp Gerontol. 2019 Jul 15;122:109-115. doi: 10.1016/j.exger.2019.04.015. Epub 2019 Apr 24.
Threat-related changes in postural control and their associations with changes in emotional and cognitive states are influenced by postural threat experience, however, limited work has explored individuals' capacity to adapt threat-related responses over longer periods of threat exposure. This study examined the effects of initial and repeated postural threat exposure on emotional, cognitive, and postural responses. Twenty-seven young and twenty-seven older adults stood on a force plate fixed to a translating platform. Threat was manipulated through expectation of a temporally and directionally (left or right) unpredictable platform perturbation. Participants completed one 60s stance trial with no expectation of perturbation (No Threat) followed by 24 trials with threat of perturbation (Threat). The stance period before each perturbation varied (5-60s) except on an early Threat trial and the last Threat trial (60s), which were used for analysis. Postural threat elicited similar emotional, cognitive, and postural changes in young and older adults. With initial threat exposure, participants reported increases in self-reported anxiety and physiological arousal, as well as broad changes in attention focus. Participants also significantly increased centre of pressure (COP) amplitude and frequency, and COP power within medium and high frequencies. With repeated threat exposure, anxiety, arousal, and some threat-induced changes in attention focus significantly adapted. These changes were accompanied by significant reductions in COP frequency and COP power within medium frequencies. Some emotional and cognitive outcomes returned to no threat levels while postural outcomes did not. This study suggests that some threat-related changes in standing postural control may be closely linked with one's emotional response to threat, while others may be context-dependent.
姿势控制与情绪和认知状态变化的关联受姿势威胁经验的影响，但很少有研究探讨个体在较长时间的威胁暴露下适应威胁相关反应的能力。本研究考察了初始和重复的姿势威胁暴露对情绪、认知和姿势反应的影响。27 名年轻和 27 名老年成年人站在固定在平移平台上的力板上。通过预期平台的时间和方向（左或右）不可预测的扰动来操纵威胁。参与者完成了一个 60 秒的无预期扰动的站立试验（无威胁），然后进行了 24 次有威胁的扰动试验（威胁）。每个扰动前的站立时间不同（5-60 秒），但在早期的威胁试验和最后一次威胁试验（60 秒）中是相同的，用于分析。姿势威胁在年轻和老年成年人中引起了类似的情绪、认知和姿势变化。在初始威胁暴露时，参与者报告自我报告的焦虑和生理唤醒增加，以及注意力焦点的广泛变化。参与者还显著增加了中心压力（COP）幅度和频率，以及中高频率范围内的 COP 功率。随着重复的威胁暴露，焦虑、唤醒和一些与威胁相关的注意力焦点变化显著适应。这些变化伴随着 COP 频率和中频率范围内 COP 功率的显著降低。一些情绪和认知结果恢复到无威胁水平，而姿势结果没有。本研究表明，站立姿势控制的一些与威胁相关的变化可能与个体对威胁的情绪反应密切相关，而其他变化可能与环境有关。
