Effect of low-frequency magnetic fields on brain electrical activity in human subjects

105

In recent years a growing number of people have begun to use mobile phone technology. This phenomenon has raised questions and doubts about possible effects on users' brains. This literature review focuses on the human electrophysiological and neuro-metabolic effects of mobile phone (MP)-related electromagnetic fields (EMFs) published in the last 10 years. To this end, all relevant papers have been reported and, subsequently, a literature selection has been carried out by taking several criteria into account, such as: blind techniques, randomization or counter-balancing of conditions and subjects, detail of exposure characteristics and the statistical analyses used. As a result, only the studies meeting the selection criteria have been described, evaluated and discussed further. The main goal of this review is to provide a clear scenario of the most reliable experiments carried out over the last decade and to offer a critical point of view in their evaluation. It is concluded that MP-EMFs may influence normal physiology through changes in cortical excitability and that in future research particular care should be dedicated to both methodological and statistical control, the most relevant criteria in this research field.

Section: Discussion and Perspectivesmentioning

confidence: 99%

Neurophysiological effects of mobile phone electromagnetic fields on humans: A comprehensive review

Valentini¹,

Curcio²,

Moroni³

et al. 2007

105

“…Conversely, Crasson and Legros [2005] attempted to replicate and extend their previous work [Crasson et al, 1999] Fuller et al [2003] 2000 mT <60 min " epileptiform activity (medial temporal lobe) Marino et al [2004] 60 Hz 100 mT; 2 s exposure " % recurrence over occipital, parietal, central regions Cook et al [2004] Pulsed ELF 200 mT pk-pk ; 15 min " occipital alpha activity (8-13 Hz) Cook et al [2005] Pulsed ELF 200 mT pk-pk ; 15 min # alpha activity in first 5 min of MF exposure Crasson and Legros [2005] 50 Hz, 100 mT rms; 30 min No effect Ghione et al [2005] 50 Hz 40 and 80 mT pk ; 15 min " occipital alpha activity (8-13 Hz)…”

Section: Static and Extremely Low Frequency Magnetic Field Effects Stmentioning

confidence: 91%

“…Postexposure, maximal effects on EEG and ERPs may occur over periods ranging in duration from minutes to hours [e.g., Fuller et al, 2003;Cook et al, 2004]. This position is far from universally supported, as many studies do not investigate effects over a long enough post-exposure duration [Marino et al, 2004;Ghione et al, 2005] and at least one study has failed to observe significant effects [e.g., Cook et al, 2005] during this period. An overview of the results of these studies can be found in Table 2.…”

Section: Static and Extremely Low Frequency Magnetic Field Effects Stmentioning

confidence: 95%

“…Marino et al [2004], using a technique from nonlinear dynamics called percent recurrence (%R, a measure of how much a signal correlates with itself in phase space), investigated intrasubject EEG responses during exposure to a 60 Hz, 100 mT MF. They found that eight out of eight subjects detected the MF as evidenced by significant changes in %R calculated from at least two electrodes (C3, C4 central; P3, P4, parietal; O1, O2, occipital) in each subject.…”

Section: Static and Extremely Low Frequency Magnetic Field Effects Stmentioning

confidence: 99%

See 1 more Smart Citation

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

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.

“…The effects of magnetic fields on the electrical activity of the brain have been investigated by analysing the spectral power of the main frequency bands of the EEG [Silny, 1986;Gamberale et al, 1989;Bell et al, 1991Bell et al, , 1992Bell et al, , 1994aLyskov et al, 1993a;Marino et al, 1996Marino et al, , 2004Schienle et al, 1996;Heusser et al, 1997;Cook et al, 2004]. These studies have used a wide variety of experimental designs and exposure conditions, as well as healthy volunteers and patients with neurological conditions, and thus are difficult to compare and evaluate.…”

Section: Effects On the Electroencephalogram (Eeg)mentioning

confidence: 99%

Neurobehavioural effects of electromagnetic fields

Sienkiewicz¹,

Jones²,

Bottomley³

2005

Very few laboratory studies in children have explored the effects of exposure to low level electromagnetic fields (EMFs) on neurobehavioural function. Studies investigating effect on neurotransmitters, cognitive function and brain activity in adults and animals indicate that acute exposure to EMFs does not appear to engender any consistent physiological or behavioural impairment although a few subtle effects may occur. This suggests that exposure of children to low level EMFs may not cause significant detrimental effects on brain function. However the available evidence is not sufficient to draw any definite conclusions, and further laboratory studies are required. In particular, experiments investigating the effects of radiofrequency (RF) fields on the performance of well-characterised cognitive and behavioural tasks by immature and developing animals are recommended, if studies with children cannot be performed for ethical and practical reasons.