Center of Neurology, Division of Neuropsychology, Hertie-Institute for Clinical Brain Research, University of Tübingen, Hoppe Seyler Str. 3, 72076, Tübingen, Germany.
Tübingen Center for Mental Health, Department of Psychiatry and Psychotherapy, University of Tübingen, Tübingen, Germany.
Sci Rep. 2024 Jun 3;14(1):12657. doi: 10.1038/s41598-024-62981-5.
When lying inside a MRI scanner and even in the absence of any motion, the static magnetic field of MRI scanners induces a magneto-hydrodynamic stimulation of subjects' vestibular organ (MVS). MVS thereby not only causes a horizontal vestibular nystagmus but also induces a horizontal bias in spatial attention. In this study, we aimed to determine the time course of MVS-induced biases in both VOR and spatial attention inside a 3 T MRI-scanner as well as their respective aftereffects after participants left the scanner. Eye movements and overt spatial attention in a visual search task were assessed in healthy volunteers before, during, and after a one-hour MVS period. All participants exhibited a VOR inside the scanner, which declined over time but never vanished completely. Importantly, there was also an MVS-induced horizontal bias in spatial attention and exploration, which persisted throughout the entire hour within the scanner. Upon exiting the scanner, we observed aftereffects in the opposite direction manifested in both the VOR and in spatial attention, which were statistically no longer detectable after 7 min. Sustained MVS effects on spatial attention have important implications for the design and interpretation of fMRI-studies and for the development of therapeutic interventions counteracting spatial neglect.
当躺在 MRI 扫描仪内，即使没有任何运动，MRI 扫描仪的静态磁场也会对受试者的前庭器官（MVS）产生磁流体动力学刺激。MVS 不仅会引起水平性前庭眼球震颤，还会引起空间注意力的水平偏差。在这项研究中，我们旨在确定在 3T MRI 扫描仪内 MVS 引起的 VOR 和空间注意力偏差的时间过程，以及参与者离开扫描仪后的各自后效。在一个小时的 MVS 期间，健康志愿者在进入、期间和离开扫描仪后评估眼动和视觉搜索任务中的显性空间注意力。所有参与者在扫描仪内都表现出 VOR，随着时间的推移而下降，但从未完全消失。重要的是，空间注意力和探索也存在 MVS 诱导的水平偏差，这种偏差在整个扫描过程中一直持续存在。当离开扫描仪时，我们观察到相反方向的后效，在 VOR 和空间注意力中都表现出来，在 7 分钟后统计学上不再可检测到。MVS 对空间注意力的持续影响对 fMRI 研究的设计和解释以及开发对抗空间忽视的治疗干预措施具有重要意义。
