Speaker
Description
The human vestibular system, like the visual system, relies on ribbon synapses and graded potentials, making it potentially sensitive to extremely low-frequency magnetic fields (ELF-MF) and induced electric fields (E-fields). While magnetophosphenes—visual sensations triggered by ELF-MF—are well-documented, direct effects on vestibular function remain inconclusive. Recent studies suggest vestibular-specific E-field stimulation can modulate postural sway beyond traditionally recognized frequency ranges. Here, we replicated the findings of Nissi et al. (2024), demonstrating that sinusoidal E-field stimulation influences balance control up to 10 Hz. Using a controlled experimental design, we apply binaural bipolar electrical vestibular stimulation (EVS) at frequencies up to 10 Hz in young, healthy participants (N = 15). Postural sway was quantified via center-of-pressure (COP) analysis on a force platform, with spectrogram analyses confirming synchronized vestibular-induced oscillations. Crucially, we found that sway responses were craniocentric, aligning with vestibular physiology: participants sway in the frontal plane when facing forward, with a reversal of modulation when the head is turned 90°. These findings extend the known frequency response of the vestibular system and reinforce its sensitivity to weak E-fields. Given prior evidence of vestibular myogenic responses within ELF ranges, our results highlight the need to investigate potential vestibular effects at powerline frequencies (50–60 Hz). This work has important implications for understanding ELF-MF exposure effects, refining international safety guidelines, and advancing vestibular stimulation techniques for research and clinical applications.
