6,486 Studies Reviewed. 85.2% of Original Studies Found Biological Effects. The Evidence is Clear.
Shield Your Body

Note: This study found no significant biological effects under its experimental conditions. We include all studies for scientific completeness.

Brain & Nervous System

Pulsed and continuous wave mobile phone exposure over left versus right hemisphere: Effects on human cognitive function

No Effects Found

Haarala C, Takio F, Rintee T, Laine M, Koivisto M, Revonsuo A, Hämäläinen H. · 2007

View Original Abstract
Share:

Mobile phone radiation at regulatory levels showed no immediate effects on basic thinking skills in this controlled study.

Plain English Summary

Summary written for general audiences

Finnish researchers tested whether mobile phone radiation affects thinking skills by having 36 men perform cognitive tasks while exposed to different types of phone signals on either the left or right side of their heads. They found no measurable differences in mental performance between real phone radiation exposure and fake exposure, regardless of which side of the head was exposed. The study suggests that typical mobile phone use doesn't impair basic cognitive functions like memory or attention in healthy adults.

Why This Matters

This study adds to the mixed body of research on mobile phone radiation and cognitive function, but its negative findings shouldn't be viewed as definitive proof of safety. The researchers used SAR levels up to 1.18 W/kg, which is within regulatory limits but represents significant exposure during the testing period. What's notable is the rigorous methodology including both pulsed and continuous wave signals, hemisphere-specific exposure, and proper blinding protocols. However, the study only examined acute effects during a single exposure session and focused on basic cognitive tasks rather than more subtle neurological functions. The reality is that cognitive effects from EMF exposure may require longer-term exposure or manifest in ways not captured by standard behavioral tests. While this research provides some reassurance about immediate cognitive impacts, it doesn't address the broader questions about chronic exposure effects or more sensitive biological endpoints.

Exposure Details

SAR
0.738,1.1, 1.18 W/kg
Source/Device
902 MHz Pulsed and continuous wave mobile phone

Exposure Context

This study used 0.738,1.1, 1.18 W/kg for SAR (device absorption):

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: 0.738,1.1, 1.18 W/kgExtreme Concern - 0.1 W/kgFCC Limit - 1.6 W/kgEffects observed in the Extreme Concern range (Building Biology)FCC limit is 2 times higher than this level
A logarithmic frequency spectrum from 10 Hz to 100 GHz showing where this study's 902 MHz exposure sits relative to common EMF sources.Where This Frequency Sits on the EMF SpectrumELFVLFLF / MFHF / VHFUHFSHFmm10 Hz100 GHzThis study: 902 MHzPower lines50/60 Hz5G mm28 GHzLogarithmic scale

Study Details

To assess the effects of both continuous wave and pulsed wave electromagnetic fields on human cognitive function as measured by behavioral tests in 36 healthy male subjects.

The possible effects of continuous wave (CW) and pulse modulated (PM) electromagnetic field (EMF) on...

No effects were found between the different EMF conditions, separate hemisphere exposures, or betwee...

In conclusion, the current results indicate that normal mobile phones have no discernible effect on human cognitive function as measured by behavioral tests.

Cite This Study
Haarala C, Takio F, Rintee T, Laine M, Koivisto M, Revonsuo A, Hämäläinen H. (2007). Pulsed and continuous wave mobile phone exposure over left versus right hemisphere: Effects on human cognitive function Bioelectromagnetics. 28(4):289-295, 2007.
Show BibTeX
@article{c_2007_pulsed_and_continuous_wave_2759,
  author = {Haarala C and Takio F and Rintee T and Laine M and Koivisto M and Revonsuo A and Hämäläinen H. },
  title = {Pulsed and continuous wave mobile phone exposure over left versus right hemisphere: Effects on human cognitive function},
  year = {2007},
  doi = {10.1002/bem.20287},
  url = {https://onlinelibrary.wiley.com/doi/abs/10.1002/bem.20287},
}
DOI: 10.1002/bem.20287

Cited By (74 papers)

View all 74 citing papers on Semantic Scholar

Quick Questions About This Study

No, 902 MHz pulsed mobile phone radiation does not affect cognitive performance. Finnish researchers tested 36 men performing thinking tasks while exposed to different phone signals and found no measurable differences in mental performance between real radiation exposure and fake exposure.
Mobile phone radiation exposure on either the left or right side of the head does not impact thinking abilities. The 2007 study found no differences in cognitive function regardless of which hemisphere was exposed to phone signals.
Continuous wave and pulsed mobile phone signals do not affect the brain differently in terms of cognitive function. Research comparing both signal types at 902 MHz found no measurable impact on memory, attention, or other thinking skills.
There is no difference between real and fake phone radiation exposure on cognition. The controlled study found identical cognitive test results whether participants were exposed to actual 902 MHz phone signals or sham exposure conditions.
Normal mobile phone use does not impair basic cognitive functions in healthy adults. Finnish researchers concluded that typical phone exposure has no discernible effect on human cognitive function as measured by behavioral performance tests.