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Human cognitive performance in a 3 mT power-line frequency magnetic field.

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Corbacio M, Brown S, Dubois S, Goulet D, Prato FS, Thomas AW, Legros A. · 2011

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Strong magnetic fields blocked normal learning improvement in memory tests, suggesting EMFs may interfere with brain plasticity.

Plain English Summary

Summary written for general audiences

Researchers exposed 99 people to a strong 60 Hz magnetic field (3 mT) for 30 minutes while they performed memory and thinking tests. While the magnetic field didn't clearly impair cognitive performance overall, it did prevent the normal learning improvement that occurs when people repeat the same memory test. This suggests that power-line frequency magnetic fields may interfere with the brain's ability to form new memories through practice.

Why This Matters

This study reveals a subtle but concerning effect of extremely low frequency magnetic fields on brain function. The 3 mT exposure level used here is significantly higher than typical household exposures (which range from 0.01 to 0.2 mT), but it's within the range that workers in certain industries or people living very close to power lines might encounter. What makes this research particularly noteworthy is that it detected an effect on synaptic plasticity - the brain's fundamental mechanism for learning and memory formation. The researchers found that magnetic field exposure blocked the normal practice effect, where performance improves with repetition. This suggests that even when EMFs don't cause obvious cognitive impairment, they may still interfere with the brain's ability to adapt and learn. The science demonstrates that our nervous systems are more sensitive to electromagnetic interference than many realize, and this study adds to growing evidence that we should take precautionary steps to limit unnecessary EMF exposures, especially in environments where learning and memory are critical.

Exposure Details

Magnetic Field
3 mG
Source/Device
60 Hz
Exposure Duration
30 min

Exposure Context

This study used 3 mG for magnetic fields:

Building Biology guidelines are practitioner-based limits from real-world assessments. BioInitiative Report recommendations are based on peer-reviewed science. Check Your Exposure to compare your own measurements.

Where This Falls on the Concern Scale

Study Exposure Level in ContextStudy Exposure Level in ContextThis study: 3 mGExtreme Concern - 5 mGFCC Limit - 2,000 mGEffects observed in the Severe Concern rangeFCC limit is 667x higher than this level
A logarithmic frequency spectrum from 10 Hz to 100 GHz showing where this study's 60 Hz exposure sits relative to common EMF sources.Where This Frequency Sits on the EMF SpectrumELFVLFLF / MFHF / VHFUHFSHFmm10 Hz100 GHzThis study: 60 HzCell phones~1 GHzWiFi2.4 GHz5G mm28 GHzLogarithmic scale

Study Details

This research aims to evaluate the impact of a 60 Hz, 3 mT MF on human cognitive performance.

Ninety‐nine participants completed the double‐blind protocol, performing a selection of psychometric...

Performance between repetitions improved in 11 of 15 psychometric parameters (practice effect). A si...

Overall, this study does not establish any clear MF effect on human cognition. It is speculated that an ELF MF may interfere with the neuropsychological processes responsible for this short‐term learning effect supported by brain synaptic plasticity.

Cite This Study
Corbacio M, Brown S, Dubois S, Goulet D, Prato FS, Thomas AW, Legros A. (2011). Human cognitive performance in a 3 mT power-line frequency magnetic field. Bioelectromagnetics. 32(8):620-633, 2011.
Show BibTeX
@article{m_2011_human_cognitive_performance_in_234,
  author = {Corbacio M and Brown S and Dubois S and Goulet D and Prato FS and Thomas AW and Legros A. },
  title = {Human cognitive performance in a 3 mT power-line frequency magnetic field.},
  year = {2011},
  doi = {10.1002/bem.20676},
  url = {https://onlinelibrary.wiley.com/doi/abs/10.1002/bem.20676},
}
DOI: 10.1002/bem.20676

Cited By (25 papers)

Quick Questions About This Study

A 2011 study found that strong 60 Hz magnetic fields from power lines may interfere with memory formation. While overall cognitive performance wasn't impaired, participants exposed to the magnetic field failed to show normal learning improvements when repeating memory tests, suggesting disrupted brain plasticity.
Research shows 60 Hz magnetic fields may impact specific brain processes. A study of 99 people found that exposure prevented the typical practice-related improvement on memory tests, though general cognitive performance remained unchanged. This suggests interference with short-term learning mechanisms.
Studies show mixed results for EMF effects on thinking abilities. One 2011 study found that strong power-line frequency magnetic fields didn't clearly impair overall cognitive performance, but they did prevent normal learning improvements, indicating potential interference with memory formation processes.
Strong magnetic fields may disrupt the brain's ability to form new memories through practice. Research found that people exposed to 60 Hz magnetic fields failed to show expected improvements when repeating memory tests, suggesting interference with synaptic plasticity underlying short-term learning.
Power line EMF may affect specific brain learning processes rather than overall cognitive function. A controlled study found that 60 Hz magnetic field exposure prevented normal practice-related improvements on memory tests, suggesting potential interference with the neurological mechanisms responsible for short-term learning.