Transduction of the Geomagnetic Field as Evidenced from alpha-Band Activity in the Human Brain.
Wang CX, Hilburn IA, Wu DA , Mizuhara Y, Cousté CP, Abrahams JNH, Bernstein SE, Matani A, Shimojo S, Kirschvink JL. · 2019
View Original AbstractHumans unconsciously detect Earth-strength magnetic fields through brain activity changes, suggesting we retain evolutionary magnetic sensing abilities.
Plain English Summary
Researchers exposed participants to Earth-strength magnetic fields while monitoring their brain activity with EEG. They discovered that specific magnetic field rotations caused measurable changes in brain waves (alpha oscillations), but only when the field was oriented as it naturally occurs in the Northern Hemisphere. This suggests humans possess an unconscious magnetic sensing ability similar to migratory animals.
Why This Matters
This groundbreaking research provides the first clear evidence that human brains respond to magnetic fields at Earth's natural strength - roughly 50 microtesla, which is thousands of times weaker than typical MRI machines but similar to what we encounter from some household appliances and power lines. What makes this study remarkable is that it demonstrates our brains are evolutionarily tuned to detect magnetic fields, even though we're not consciously aware of it. The researchers ruled out electrical artifacts and identified ferromagnetism as the likely mechanism, suggesting we have magnetite crystals in our brains that act as biological compasses. This finding challenges the assumption that humans have lost the magnetic sensing abilities found throughout the animal kingdom and raises important questions about how artificial magnetic fields from our technology might interfere with this ancient biological system.
Exposure Information
Specific exposure levels were not quantified in this study. The study examined exposure from: 8-13 Hz
Study Details
We report here a strong, specific human brain response to ecologically-relevant rotations of Earth-strength magnetic fields
Following geomagnetic stimulation, a drop in amplitude of EEG alpha oscillations (8-13 Hz) occurred ...
Biophysical tests showed that the neural response was sensitive to static components of the magnetic field. This rules out all forms of electrical induction (including artifacts from the electrodes) which are determined solely on dynamic components of the field. The neural response was also sensitive to the polarity of the magnetic field. This rules out free-radical 'quantum compass' mechanisms like the cryptochrome hypothesis, which can detect only axial alignment. Ferromagnetism remains a viable biophysical mechanism for sensory transduction and provides a basis to start the behavioral exploration of human magnetoreception.
Show BibTeX
@article{cx_2019_transduction_of_the_geomagnetic_1778,
author = {Wang CX and Hilburn IA and Wu DA and Mizuhara Y and Cousté CP and Abrahams JNH and Bernstein SE and Matani A and Shimojo S and Kirschvink JL.},
title = {Transduction of the Geomagnetic Field as Evidenced from alpha-Band Activity in the Human Brain.},
year = {2019},
url = {https://www.eneuro.org/content/early/2019/03/18/ENEURO.0483-18.2019?versioned=true},
}