Visual motion combined with base of support width reveals variable field dependency in healthy young adults.
Visual motion combined with base of support width reveals variable field dependency in healthy young adults.
复制标题
视觉运动与支撑宽度的结合揭示了健康年轻人的可变场依赖性。
DOI：
10.1007/s00221-006-0677-2
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发表时间：
2007
影响因子：
2
通讯作者：
Keshner,EmilyA
中科院分区：
文献类型：
--
作者：
Streepey,JeffersonW;Kenyon,RobertV;Keshner,EmilyA
我们先前报道了年轻健康个体站在不同大小的块上观察窄（两个方向均为25°）和宽（水平和垂直方向分别为90°和55°）视野（FOV）时对诱导姿势不稳定的反应。视觉运动是使用沉浸式虚拟环境实现的，该虚拟环境随着头部运动（自然运动）逼真地移动，并在前后方向上以0.1 Hz正弦平移（增强运动）。我们观察到，一个子集的主题（步进器）不能保持连续的立场上最小的块时，虚拟环境中的运动。我们完成了一个后验分析的步进器和非步进器的姿势反应，可能会告诉我们这些差异的稳定性的机制。我们发现，当观看增强运动与宽FOV，有一个更大的影响，头部和全身的质心和踝关节角度均方根（RMS）值的步进器比非步进器。FFT分析显示，更大的功率在频率的视觉刺激的步进相比，非步进。全身COM时间滞后相对于增强视觉场景显示，现场和COM之间的时间延迟显着增加的步进器。视觉信息的反应性增加表明，更大的视野依赖性的步进器，并表明从依赖视觉信息的体感信息的阈值可以不同，即使在一个健康的人群。
We previously reported responses to induced postural instability in young healthy individuals viewing visual motion with a narrow (25° in both directions) and wide (90° and 55° in the horizontal and vertical directions) field of view (FOV) as they stood on different sized blocks. Visual motion was achieved using an immersive virtual environment that moved realistically with head motion (natural motion) and translated sinusoidally at 0.1 Hz in the fore-aft direction (augmented motion). We observed that a subset of the subjects (steppers) could not maintain continuous stance on the smallest block when the virtual environment was in motion. We completed a posteriori analyses on the postural responses of the steppers and non-steppers that may inform us about the mechanisms underlying these differences in stability. We found that when viewing augmented motion with a wide FOV, there was a greater effect on the head and whole body center of mass and ankle angle root mean square (RMS) values of the steppers than of the non-steppers. FFT analyses revealed greater power at the frequency of the visual stimulus in the steppers compared to the non-steppers. Whole body COM time lags relative to the augmented visual scene revealed that the time-delay between the scene and the COM was significantly increased in the steppers. The increased responsiveness to visual information suggests a greater visual field-dependency of the steppers and suggests that the thresholds for shifting from a reliance on visual information to somatosensory information can differ even within a healthy population.