PDF(Pubmed)
Abstract：
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.
摘要：
当躺在MRI扫描仪中甚至没有任何运动时，MRI扫描仪的静态磁场诱导受试者前庭器官（MVS）的磁流体动力学刺激。因此，MVS不仅会引起水平前庭眼球震颤，还会引起空间注意力的水平偏向。在这项研究中,我们旨在确定3TMRI扫描仪中MVS引起的VOR和空间注意力偏差的时程,以及参与者离开扫描仪后各自的副作用.以前在健康志愿者中评估了视觉搜索任务中的眼球运动和明显的空间注意力，during,经过一小时的MVS。所有参与者都在扫描仪内展示了VOR，随着时间的推移而下降，但从未完全消失。重要的是,在空间关注和探索中也存在MVS引起的水平偏差，它在扫描仪中持续了整整一个小时。退出扫描仪后，我们观察到在VOR和空间注意力中表现出的相反方向的后效应，7分钟后统计学上不再检测到。MVS对空间注意力的持续影响对于fMRI研究的设计和解释以及消除空间忽视的治疗干预措施的发展具有重要意义。
