Heimbrand S, Müller M, Schweigart G, Mergner T
Abteilung Neurologie, Universität Freiburg, Germany.
J Vestib Res. 1990;1(3):291-8.
In patients with loss of vestibular functions, we studied psychophysically the self-motion perception for 'trunk in space' and 'head in space' during various combinations of horizontal head and trunk rotation in the dark. The results were compared to those of normal subjects. For their 'trunk in space' perception, the subjects relied on their internal image of space, derived from the vestibular receptors in the head, and referred their trunk to this as a reference by adding to it a nuchal trunk-to-head signal. The patients, by contrast, always considered the trunk as stationary. Obviously because they were devoid of any space cues, they abandoned or suppressed a neck contribution to their 'trunk in space' perception, which, in fact, would yield an erroneous perception in almost all conditions in the dark. Both the patients and the subjects based their 'head in space' perception on their internal representation of 'trunk in space' and added to this a nuchal head-to-trunk signal. However, the patients' head-to-trunk signal, unlike that of the subjects, was considerably larger than the actual head-to-trunk rotation at low stimulus frequency. We relate this finding to some unconscious modification of their neck muscle activity during passive head rotation. It appears that the patients' gain of the neck input per se is not increased, but rather that subsets of this input are modified according to the particular function they serve.
在丧失前庭功能的患者中，我们在黑暗环境下对水平头部和躯干旋转的各种组合过程中“躯干在空间中”和“头部在空间中”的自我运动感知进行了心理物理学研究。将结果与正常受试者的结果进行了比较。对于他们“躯干在空间中”的感知，受试者依赖于源自头部前庭感受器的内部空间图像，并通过向其添加项部躯干至头部的信号，将他们的躯干以此作为参考。相比之下，患者总是认为躯干是静止的。显然，由于他们缺乏任何空间线索，他们放弃或抑制了颈部对其“躯干在空间中”感知的贡献，而这实际上在黑暗中的几乎所有情况下都会产生错误的感知。患者和受试者都将他们“头部在空间中”的感知基于他们对“躯干在空间中”的内部表征，并在此基础上添加项部头部至躯干的信号。然而，与受试者不同的是，患者的头部至躯干信号在低刺激频率下比实际的头部至躯干旋转要大得多。我们将这一发现与他们在被动头部旋转过程中颈部肌肉活动的一些无意识改变联系起来。似乎患者颈部输入本身的增益并没有增加，而是该输入的子集根据它们所服务的特定功能进行了修改。
