Stabilization and mobility of the head and trunk in wild monkeys during terrestrial and flat-surface walks and gallops
Stabilization and mobility of the head and trunk in wild monkeys during terrestrial and flat-surface walks and gallops
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DOI：
10.1242/jeb.00863
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发表时间：
2004-02-01
影响因子：
2.8
通讯作者：
Vieilledent, S
中科院分区：
文献类型：
--
作者：
Dunbar, DC;Badam, GL;Vieilledent, S
本研究研究了野生印度猴在地面和墙壁平顶表面上自然运动时头部和躯干的旋转活动性（约20度）和稳定性（小于或等于20度）模式。对成年雌雄雌雄的半人叶猴（Semnopithecus entellus）和帽猴（Macaca radiata）进行了侧面拍摄。从电影胶片上测量了全身水平线性位移、头部和躯干相对于空间（地球水平）的俯仰位移以及头部垂直位移。根据头对空间和躯干对空间的测量计算头对躯干的俯仰角。然后根据位移数据计算运动速度、周期持续时间、角分段速度、平均分段位置以及垂直和角头部位移的平均峰值频率。定性地观察偏航旋转。在这两个物种的四足行走中，头部可以在一个稳定的躯干上在俯仰和偏航平面上自由旋转。相比之下，两种动物在四足疾驰时，躯干都倾斜在稳定的头部上。在这两个物种的两种步态中，头部和躯干的俯仰旋转在两种步态的可比平均位置上是对称的，平均头部位置与接近地面水平的水平半规管对齐。头部俯仰方向与头部垂直位移方向在行走时有不同程度的对抗，仅在疾驰时是间歇性的，这证明纠正头部俯仰旋转对凝视稳定不是必需的。头部到太空的俯仰速度低于350°s(-1)，至少在人类中，超过这个阈值，前庭眼反射（VOR）就会饱和。头部垂直平移和俯仰旋转的平均峰值频率范围为1hz至2hz，低于这些物种中被预测为头部主要稳定器的惯性的频率范围。在这两个物种中，行走和奔跑都有一些共同的变量，可能反映了感觉运动控制的限制。其他变量，在两个物种的两个步态之间的差异，可能反映了运动学的差异，而两个物种之间的差异变量主要归因于形态和行为的差异。结论是，无论是头部还是躯干都可以为神经系统提供空间定位的参考框架，并且根据所选步态的运动学特征，提供参考的部分可以改变。
This study investigated the patterns of rotational mobility (>20degrees) and stability (less than or equal to20degrees) of the head and trunk in wild Indian monkeys during natural locomotion on the ground and on the flat-topped surfaces of walls. Adult hanuman langurs (Semnopithecus entellus) and bonnet macaques (Macaca radiata) of either gender were cine filmed in lateral view. Whole-body horizontal linear displacement, head and trunk pitch displacement relative to space (earth horizontal), and vertical head displacement were measured from the cine films. Head-to-trunk pitch angle was calculated from the head-to-space and trunk-to-space measurements. Locomotor velocities, cycle durations, angular segmental velocities, mean segmental positions and mean peak frequencies of vertical and angular head displacements were then calculated from the displacement data. Yaw rotations were observed qualitatively. During quadrupedal walks by both species, the head was free to rotate in the pitch and yaw planes on a stabilized trunk. By contrast, during quadrupedal gallops by both species, the trunk pitched on a stabilized head. During both gaits in both species, head and trunk pitch rotations were symmetrical about comparable mean positions in both gaits, with mean head position aligning the horizontal semicircular canals near earth horizontal. Head pitch direction countered head vertical displacement direction to varying degrees during walks and only intermittently during gallops, providing evidence that correctional head pitch rotations are not essential for gaze stabilization. Head-to-space pitch velocities were below 350 deg. s(-1), the threshold above which, at least among humans, the vestibulo-ocular reflex (VOR) becomes saturated. Mean peak frequencies of vertical translations and pitch rotations of the head ranged from 1 Hz to 2 Hz, a lower frequency range than that in which inertia is predicted to be the major stabilizer of the head in these species. Some variables, which were common to both walks and gallops in both species, are likely to reflect constraints in sensorimotor control. Other variables, which differed between the two gaits in both species, are likely to reflect kinematic differences, whereas variables that differed between the two species are attributed primarily to morphological and behavioural differences. It is concluded that either the head or the trunk can provide the nervous system with a reference frame for spatial orientation and that the segment providing that reference can change, depending upon the kinematic characteristics of the chosen gait.