Tilt perception during dynamic linear acceleration.
Tilt perception during dynamic linear acceleration.
复制标题
动态线性加速期间的倾斜感知。
DOI：
10.1007/s002210050346
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发表时间：
1998
影响因子：
2
通讯作者：
Paige,GD
中科院分区：
文献类型：
--
作者：
Seidman,SH;Telford,L;Paige,GD
头部倾斜是头部相对于重力的旋转，如从自然直立取向的头部滚动或俯仰所例示的。由于重力方向的变化，头部旋转刺激耳石器官和半规管，这反过来又驱动了各种行为和感知反应。倾斜知觉的研究通常没有充分隔离耳石和运河输入或其动态贡献。真正的倾斜不能轻易地将耳石与耳道的影响分开。可替代地，离心产生模拟倾斜的向心加速度，但在刺激曲线的重要时段期间仍然需要旋转（通道）刺激。我们重新评估了人类头部倾斜的感知，但仅将刺激限制为线性力，从而隔离耳石输入的影响。这是通过采用离心技术与可变半径的旋转雪橇。这使我们能够将雪橇加速到恒定的角速度（128°/s），使受试者居中，然后在所有旋转感知消失后施加动态向心加速度。这些刺激呈现在受试者的鼻枕轴，通过将受试者向前或向后偏心平移50 cm。向心加速度，从而诱导（0.25克），这与重力相结合，以产生一个动态变化的重力惯性力模拟俯仰倾斜，但实际上没有旋转的头部。一个大小估计任务的特点动态感知的俯仰倾斜。线性加速度反应迟钝，通常在10-30秒后达到峰值。知觉的适应性也表现出来。适应表现为在长时间刺激期间感知倾斜的每刺激下降和在返回到零加速度时的逆转后效（即，重新定位主题）。我们的结论是耳石输入可以产生倾斜的感觉，在没有运河刺激，这种感觉是受适应现象和低通滤波的耳石输入。
Head tilt is a rotation of the head relative to gravity, as exemplified by head roll or pitch from the natural upright orientation. Tilt stimulates both the otolith organs, owing to shifts in gravitational orientation, and the semicircular canals in response to head rotation, which in turn drive a variety of behavioral and perceptual responses. Studies of tilt perception typically have not adequately isolated otolith and canal inputs or their dynamic contributions. True tilt cannot readily dissociate otolith from canal influences. Alternatively, centrifugation generates centripetal accelerations that simulate tilt, but still entails a rotatory (canal) stimulus during important periods of the stimulus profiles. We reevaluated the perception of head tilt in humans, but limited the stimulus to linear forces alone, thus isolating the influence of otolith inputs. This was accomplished by employing a centrifugation technique with a variable-radius spinning sled. This allowed us to accelerate the sled to a constant angular velocity (128°/s), with the subject centered, and then apply dynamic centripetal accelerations after all rotatory perceptions were extinguished. These stimuli were presented in the subjects’ naso-occipital axis by translating the subjects 50 cm eccentrically either forward or backward. Centripetal accelerations were thus induced (0.25 g), which combined with gravity to yield a dynamically shifting gravitoinertial force simulating pitch-tilt, but without actually rotating the head. A magnitude-estimation task was employed to characterize the dynamic perception of pitch-tilt. Tilt perception responded sluggishly to linear acceleration, typically reaching a peak after 10–30 s. Tilt perception also displayed an adaptation phenomenon. Adaptation was manifested as a per-stimulus decline in perceived tilt during prolonged stimulation and a reversal aftereffect upon return to zero acceleration (i.e., recentering the subject). We conclude that otolith inputs can produce tilt perception in the absence of canal stimulation, and that this perception is subject to an adaptation phenomenon and low-pass filtering of its otolith input.