Wyssen Gerda, Morrison Miranda, Korda Athanasia, Wimmer Wilhelm, Otero-Millan Jorge, Ertl Matthias, Szukics Andreas A, Wyss Thomas, Wagner Franca, Caversaccio Marco D, Mantokoudis Georgios, Mast Fred W
Department of Psychology, University of Bern; Translational Imaging Center (TIC), Swiss Institute for Translational and Entrepreneurial Medicine;
Department of Otorhinolaryngology, Head and Neck Surgery, lnselspital, University Hospital Bern and University of Bern.
J Vis Exp. 2023 Mar 3(193). doi: 10.3791/64022.
Strong magnetic fields induce dizziness, vertigo, and nystagmus due to Lorentz forces acting on the cupula in the semi-circular canals, an effect called magnetic vestibular stimulation (MVS). In this article, we present an experimental setup in a 7T MRT scanner (MRI scanner) that allows the investigation of the influence of strong magnetic fields on nystagmus as well as perceptual and cognitive responses. The strength of MVS is manipulated by altering the head positions of the participants. The orientation of the participants' semicircular canals with respect to the static magnetic field is assessed by combining a 3D magnetometer and 3D constructive interference in steady-state (3D-CISS) images. This approach allows to account for intra- and inter-individual differences in participants' responses to MVS. In the future, MVS can be useful for clinical research, for example, in the investigation of compensatory processes in vestibular disorders. Furthermore, it could foster insights into the interplay between vestibular information and cognitive processes in terms of spatial cognition and the emergence of self-motion percepts under conflicting sensory information. In fMRI studies, MVS can elicit a possible confounding effect, especially in tasks influenced by vestibular information or in studies comparing vestibular patients with healthy controls.
强磁场会因洛伦兹力作用于半规管中的壶腹嵴而诱发头晕、眩晕和眼球震颤，这种效应称为磁前庭刺激（MVS）。在本文中，我们展示了一种在7T磁共振成像扫描仪（MRI扫描仪）中的实验装置，该装置可用于研究强磁场对眼球震颤以及感知和认知反应的影响。通过改变参与者的头部位置来控制MVS的强度。通过结合三维磁力计和稳态三维相干成像（3D-CISS）图像来评估参与者半规管相对于静磁场的方向。这种方法能够考虑到参与者对MVS反应中的个体内差异和个体间差异。未来，MVS可用于临床研究，例如，用于研究前庭疾病中的代偿过程。此外，它还可以促进我们深入了解前庭信息与认知过程在空间认知方面的相互作用，以及在相互冲突的感觉信息下自我运动感知的出现。在功能磁共振成像研究中，MVS可能会引发一种潜在的混杂效应，尤其是在受前庭信息影响的任务中，或者在比较前庭疾病患者与健康对照的研究中。
