No influence of short-term exposure to 50-Hz magnetic fields on cognitive performance function in human

In 2002, we published a review of the cognitive and physiological effects of extremely low frequency magnetic fields (ELF MFs) and ELF-modulated radiofrequency fields associated with mobile phones. Since the original preparation of that review, a significant number of studies have been published using techniques such as electroencephalography, event-related potentials and positron emission tomography to investigate electromagnetic field effects upon human physiology and various measures of performance (cognitive, perceptual, behavioral). We review these recent studies, and when effects were observed, we reference the time course of observed effects (immediate or delayed). In our concluding remarks, we discuss a number of variables that are not often considered in human bioelectromagnetics studies, such as personality, individual differences and the specific laterality of ELF MF and mobile phone exposure over the brain. We also consider the sensitivity of various physiological assays and performance measures in the study of biological effects of electromagnetic fields.

Section: Studies Involving Performance Measures: Time Course Of Effectsmentioning

confidence: 90%

Section: Studies Involving Performance Measures: Time Course Of Effectsmentioning

confidence: 99%

Exposure to ELF magnetic and ELF‐modulated radiofrequency fields: The time course of physiological and cognitive effects observed in recent studies (2001–2005)

Cook

Saucier

Thomas

et al. 2006

“…As an indicator of the ELF-EMF/ELF-PEMF induced effects different parameters have been chosen for analysis. Among them the principal ones are heart rate variability (HRV) [Tabor et al, 2004], biochemistry [Kurokawa et al, 2003b], and cognitive functions [Kurokawa et al, 2003c;Sait et al, 2006]. For this study, HRV has been chosen as the main indicator of ELF-PEMF effect.…”

Section: Introductionmentioning

confidence: 99%

A pilot investigation of the effect of extremely low frequency pulsed electromagnetic fields on humans' heart rate variability

Baldi

Baldi²,

Lithgow

2006

The question whether pulsed electromagnetic field (PEMF) can affect the heart rhythm is still controversial. This study investigates the effects on the cardiocirculatory system of ELF-PEMFs. It is a follow-up to an investigation made of the possible therapeutic effect ELF-PEMFs, using a commercially available magneto therapeutic unit, had on soft tissue injury repair in humans. Modulation of heart rate (HR) or heart rate variability (HRV) can be detected from changes in periodicity of the R-R interval and/or from changes in the numbers of heart-beat/min (bpm), however, R-R interval analysis gives only a quantitative insight into HRV. A qualitative understanding of HRV can be obtained considering the power spectral density (PSD) of the R-R intervals Fourier transform. In this study PSD is the investigative tool used, more specifically the low frequency (LF) PSD and high frequency (HF) PSD ratio (LF/HF) which is an indicator of sympatho-vagal balance. To obtain the PSD value, variations of the R-R time intervals were evaluated from a continuously recorded ECG. The results show a HR variation in all the subjects when they are exposed to the same ELF-PEMF. This variation can be detected by observing the change in the sympatho-vagal equilibrium, which is an indicator of modulation of heart activity. Variation of the LF/HF PSD ratio mainly occurs at transition times from exposure to nonexposure, or vice versa. Also of interest are the results obtained during the exposure of one subject to a range of different ELF-PEMFs. This pilot study suggests that a full investigation into the effect of ELF-PEMFs on the cardiovascular system is justified.

“…The most recent studies using sinusoidal 50 Hz MF (at 20, 100, or 400 mT) found no effects on working memory and cognitive flexibility [Delhez et al, 2004;Nevelsteen et al, 2007], selective and sustained attention tasks [Delhez et al, 2004;Crasson and Legros, 2005;Nevelsteen et al, 2007], and reaction time or time perception [Kurokawa et al, 2003;Delhez et al, 2004;Crasson and Legros, 2005]. However, a consistent effect appears to exist when the 50 Hz exposure level is >500 mT.…”

Section: Introductionmentioning

confidence: 90%

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

Corbacio

Brown

Dubois

et al. 2011

Extremely low frequency (ELF, <300 Hz) magnetic fields (MF) have been reported to modulate cognitive performance in humans. However, little research exists with MF exposures comparable to the highest levels experienced in occupations like power line workers and industrial welders. 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 tests under two consecutive MF exposure conditions dictated by assignment to one of three groups (sham/sham, MF exposure/sham, or sham/MF exposure). Data were analyzed using a 3 × 2 mixed model analysis of variance. Performance between repetitions improved in 11 of 15 psychometric parameters (practice effect). A significant interaction effect on the digit span forward test (F = 5.21, P < 0.05) revealed an absence of practice effects for both exposure groups but not the control group. This memory test indicates MF-induced abolition of the improvement associated with practice. 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.