EFFECTS OF ACTIVITY ON POSTURAL STABILITY IN ELDERLY

活动对老年人姿势稳定性的影响

• 批准号: 6339393
• 负责人: CHARLES J DUFFY
• 金额: $ 3.77万
• 依托单位: UNIVERSITY OF ROCHESTER
• 依托单位国家: 美国
• 财政年份: 2000
• 资助国家: 美国
• 起止时间: 2000-08-01 至 2001-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6339393
• 关键词: Mammalia; bioengineering /biomedical engineering; biomedical resource; cognition; computers; eye; informatics; mental disorders; nervous system; psychology; skeletal system

An extensive study of the translational LVOR frequency response during interaural (horizontal) and dorsoventral (vertical) oscillation has been completed in squirrel monkeys. We have found that the now well-known influence of vergence on LVOR sensitivity is remarkably limited to frequencies above around 0.5 Hz. Further, phase angle displays an increasingly large lead as frequency declines from 4 to 0.5 Hz. These findings suggest that the translational LVOR behaves with high-pass filtering characteristics, as does the AVOR, but with a cut-off at a much higher frequency (0.5 in the LVOR as opposed to 0.01 in the AVOR). The LVOR was also shown to behave linearly with stimulus amplitude over the range, 0.1-0.7 g peak acceleration. This remarkable performance suggests that the LVOR operates in a bandwidth that is almost exclusively above the capabilities of vision. We have also completed a sub-project on eccentric rotation, which activates both the AVOR and LVOR simultaneously. When the subject is displaced eccentrically from the rotation axis (e.g., 40 cm), and with the nose facing out, the effect of vergence on response gain at 4 Hz increases dramatically. This reflects the addition of the LVOR to the AVOR. The LVOR is driven by interaural (with the head upright) or dorsoventral (with the head on its side) tangential acceleration induced by eccentric rotation. This component adds to the horizontal or vertical AVOR, respectively, stimulated by the rotatory motion (head yaw if upright or pitch if on side). When the subject is turned around to face in toward the rotation axis, the LVOR component of the response is reversed and subtracts from the AVOR. We then observe a decline in gain with decreasing viewing distance. At distances closer than the rotation axis, the overall ocular response reverses direction; this is so because the LVOR component overwhelms the smaller AVOR component under these viewing conditions. The frequency-dependent behavior of the VOR during eccentric rotation has been addressed in depth, and for both horizontal and vertical responses. In concert with our new understanding of the LVOR, we observe the same frequency limitations of its influence on combined AVOR-LVOR responses. That is, the LVOR component of respouses to eccentric rotation is limited to frequencies above around 0.5 Hz. Further, the AVOR and LVOR have been shown to interact linearly during complex motion, as vector additions.

对平移 LVOR 频率响应的广泛研究 在耳间（水平）和背腹（垂直）振荡期间 已在松鼠猴身上完成。 我们发现现在 众所周知，聚散度对 LVOR 灵敏度的影响非常显着 仅限于 0.5 Hz 以上的频率。进一步地，相位角 随着频率从 4 下降到 4，显示出越来越大的领先优势 0.5赫兹。这些发现表明 LVOR 的翻译行为 与 AVOR 一样，具有高通滤波特性，但具有 截止频率更高（LVOR 为 0.5，而不是 0.01） 在 AVOR 中）。 LVOR 也被证明与 刺激幅度超过该范围，峰值加速度为 0.1-0.7 g。 这 卓越的性能表明 LVOR 工作在带宽 这几乎完全超出了视觉能力。 我们有 还完成了一个关于偏心旋转的子项目，该项目激活 AVOR 和 LVOR 同时进行。 当主体发生位移时 与旋转轴偏心（例如 40 厘米），并且与鼻子 朝外，聚散度对 4 Hz 响应增益的影响增加 戏剧性地。 这体现了在AVOR的基础上增加了LVOR。 LVOR 由耳内驱动（头部直立）或 背腹（头部侧向）切向加速度 由偏心旋转引起。 该组件添加到水平 或垂直 AVOR，分别由旋转运动刺激 （如果直立则头部偏转，如果侧卧则头部俯仰）。 当话题转向 围绕面向旋转轴，LVOR 分量 响应被反转并从 AVOR 中减去。 然后我们观察一个 增益随着观看距离的减小而下降。 距离较近时 与旋转轴相比，整体眼睛反应相反 方向;之所以如此，是因为 LVOR 分量压倒了 在这些观看条件下，较小的 AVOR 分量。 这 VOR 在偏心旋转期间的频率相关行为 并针对水平和垂直方向进行了深入探讨 回应。 根据我们对 LVOR 的新理解，我们 观察其对组合的影响的相同频率限制 AVOR-LVOR 反应。 也就是说，响应的 LVOR 部分 偏心旋转仅限于高于 0.5 Hz 左右的频率。 此外，AVOR 和 LVOR 已被证明在 复杂的运动，如向量加法。