Speaker
Description
The peripheral nervous system (PNS) is a highly complex network comprising various components, including motor and sensory nerves. Whereas central nervous stimulation threshods for magnetic field (MF) exposure at powerline frequencies (50/60 Hz) are well established, PNS stimulation thresholds remain uncertain. Current estimations ranging from 2.3 to 6.15 V/m for in situ electric fields (EF). These values are derived from computational models and extrapolations, underscoring the need for experimental validation in humans to refine safety standards and guidelines. This ongoing study aims to determine PNS stimulation thresholds at powerline frequencies and assess associated neurophysiological effects using electroencephalography (EEG). We have developed a randomized, double-blind, controlled protocol involving healthy participants exposed to a powerline-frequency MF at the leg level (50 or 60 Hz) and a positive control using transcutaneous pulsed magnetic stimulation. Participants report sensations and rate perception intensity across 11 exposure levels via button-press. Simultaneously, EEG recordings capture brain activity to analyze somatosensory and motor responses. Preliminary data confirm the feasibility of the protocol, with perception thresholds successfully identified along with specific alpha-band frequency modulations. Initial results indicate a perception threshold of 45.9 T/s, with considerable inter-individual variability. These findings will contribute to a better understanding of human PNS thresholds and the neurophysiological effects of low-frequency MF exposure.
