Decrease of motor cortex excitability following exposure to a 20 Hz magnetic field as generated by a rotating permanent magnet.
Gallasch E, Rafolt D, Postruznik M, Fresnoza S, Christova M. · 2018
View Original AbstractJust 15 minutes of 20 Hz magnetic field exposure measurably reduced brain excitability in healthy volunteers.
Plain English Summary
Researchers exposed 14 healthy volunteers to 20 Hz magnetic fields generated by rotating permanent magnets for 15 minutes, then measured brain activity in the motor cortex (the brain region controlling movement). They found that this magnetic field exposure significantly reduced motor cortex excitability, meaning the brain region became less responsive to stimulation. This demonstrates that even brief exposure to rotating magnetic fields can measurably alter brain function.
Why This Matters
This study provides direct evidence that magnetic fields can alter brain function in measurable ways. The researchers used a 20 Hz frequency, which falls within the extremely low frequency (ELF) range commonly emitted by household appliances, power lines, and some electronic devices. What makes this research particularly significant is that it shows brain changes occurring after just 15 minutes of exposure using a relatively simple device - a rotating permanent magnet. The science demonstrates that our brains are not immune to magnetic field influences, contrary to what industry advocates often claim. While this was a controlled laboratory study using healthy volunteers, the findings add to a growing body of evidence showing that EMF exposure can produce biological effects in the nervous system. The reality is that we're exposed to similar frequencies daily from our electrical environment, though typically at lower intensities and for longer durations.
Exposure Information
Specific exposure levels were not quantified in this study. The study examined exposure from: 20 Hz Duration: 15 min
Study Details
The aim of this transcranial magnetic stimulation (TMS) study is to investigate whether such fields are able to influence MC excitability, and whether there are parallels to tACS induced effects.
Fourteen healthy volunteers received 20 Hz tAMF stimulation over the MC, over the vertex, and 20 Hz ...
The tACS and the tAMF stimulation over the MC affected cortical excitability in a different way. Aft...
The recorded single and paired pulse MEPs indicate a general decrease of MC excitability following 15 min of tAMF stimulation.
Show BibTeX
@article{e_2018_decrease_of_motor_cortex_1744,
author = {Gallasch E and Rafolt D and Postruznik M and Fresnoza S and Christova M.},
title = {Decrease of motor cortex excitability following exposure to a 20 Hz magnetic field as generated by a rotating permanent magnet.},
year = {2018},
url = {https://pubmed.ncbi.nlm.nih.gov/29729595/},
}