Faculty of Kinesiology and Physical Education, University of Toronto Toronto, ON, Canada.
Fédération de Recherche 3C Comportement-Cerveau-Cognition, Centre National de la Recherche Scientifique - Aix-Marseille University Marseille, France.
Front Integr Neurosci. 2013 Dec 16;7:90. doi: 10.3389/fnint.2013.00090. eCollection 2013.
Several studies have investigated whether vestibular signals can be processed to determine the magnitude of passive body motions. Many of them required subjects to report their perceived displacements offline, i.e., after being submitted to passive displacements. Here, we used a protocol that allowed us to complement these results by asking subjects to report their introspective estimation of their displacement continuously, i.e., during the ongoing body rotation. To this end, participants rotated the handle of a manipulandum around a vertical axis to indicate their perceived change of angular position in space at the same time as they were passively rotated in the dark. The rotation acceleration (Acc) and deceleration (Dec) lasted either 1.5 s (peak of 60°/s(2), referred to as being "High") or 3 s (peak of 33°/s(2), referred to as being "Low"). The participants were rotated either counter-clockwise or clockwise, and all combinations of acceleration and deceleration were tested (i.e., AccLow-DecLow; AccLow-DecHigh; AccHigh-DecLow; AccHigh-DecHigh). The participants' perception of body rotation was assessed by computing the gain, i.e., ratio between the amplitude of the perceived rotations (as measured by the rotating manipulandum's handle) and the amplitude of the actual chair rotations. The gain was measured at the end of the rotations, and was also computed separately for the acceleration and deceleration phases. Three salient findings resulted from this experiment: (i) the gain was much greater during body acceleration than during body deceleration, (ii) the gain was greater during High compared to Low accelerations and (iii) the gain measured during the deceleration was influenced by the preceding acceleration (i.e., Low or High). These different effects of the angular stimuli on the perception of body motion can be interpreted in relation to the consequences of body acceleration and deceleration on the vestibular system and on higher-order cognitive processes.
已有多项研究调查了前庭信号是否可以用于确定被动身体运动的幅度。其中许多研究要求受试者在离线时报告他们的感知位移，即在经历被动位移后报告。在这里，我们使用了一种方案，通过要求受试者在身体持续旋转时连续报告他们的内省位移估计，从而可以补充这些结果。为此，参与者围绕垂直轴旋转操纵杆手柄，以指示他们在黑暗中被动旋转时在空间中感知到的角位置变化。旋转加速度（Acc）和减速（Dec）持续 1.5 秒（峰值为 60°/s²，称为“高”）或 3 秒（峰值为 33°/s²，称为“低”）。参与者被逆时针或顺时针旋转，并且测试了所有加速和减速的组合（即 AccLow-DecLow；AccLow-DecHigh；AccHigh-DecLow；AccHigh-DecHigh）。通过计算增益（即感知旋转幅度（由旋转操纵杆手柄测量）与实际椅子旋转幅度之间的比值）来评估参与者对身体旋转的感知。增益在旋转结束时进行测量，并且也分别在加速和减速阶段进行测量。该实验得出了三个重要发现：（i）在身体加速期间增益远大于身体减速期间，（ii）在高加速时增益大于低加速时，以及（iii）在减速期间测量的增益受前加速（即低或高）的影响。这些不同的角刺激对身体运动感知的影响可以根据身体加速和减速对前庭系统和高阶认知过程的后果来解释。
