Cognitive functions in ultra-high magnetic fields: Specific Influence of Magnetic Vestibular Stimulation on Mental Rotation in 7T MRI

Strong magnetic fields in MRI scanners induce magnetic vestibular stimulation (MVS), leading to illusory motion perception, and reflexive eye movements (nystagmus). Studies outside the scanner have shown that vestibular information can interfere with cognitive tasks. This study examines the effect of MVS on cognitive functions in 30 participants performing mental rotation tasks in a 7T MRIscanner. To investigate specific cognitive components, participants completed both a mental self-rotation task and a mental figure rotation task. Tasks were performed while lying in the 7T MRI scanner under two conditions: supine (strong MVS) and tilted head position (weak MVS) to manipulate stimulation strength within-subjects. Strength of MVS was confirmed by nystagmus response using eye tracking inside the bore. Bayesian multilevel models show that stronger MVS impaired performance in mental self-rotation but performance in the figure rotation task was unaffected. These findings suggest that MVS selectively disrupts cognitive tasks reliant on own body reference frames, highlighting the influence of vestibular information on spatial cognition. This study provides first evidence of a specific effect of MVS on performance in a cognitive task, with important implications for neuroimaging research.