Electromagnetic field of mobile phones affects visual event related potential in patients with narcolepsy

Abstract

The effects of the mobile phone (MP) electromagnetic fields on electroencephalography (EEG) and event-related potentials (ERP) were examined. With regard to the reported effects of MP on sleep, 22 patients with narcolepsy-cataplexy were exposed or sham exposed for 45 min to the MP (900 MHz, specific absorption rate 0.06 W/kg) placed close to the right ear in a double blind study. There were no changes of the EEG recorded after the MP exposure. A subgroup of 17 patients was studied on visual ERP recorded during the MP exposure. Using an adapted "odd-ball" paradigm, each patient was instructed to strike a key whenever rare target stimuli were presented. There were three variants of target stimuli (horizontal stripes in (i) left, (ii) right hemifields or (iii) whole field of the screen). The exposure enhanced the positivity of the ERP endogenous complex solely in response to target stimuli in the right hemifield of the screen (P < 0.01). The reaction time was shortened by 20 ms in response to all target stimuli (P < 0.05). In conclusion, the electromagnetic field of MP may suppress the excessive sleepiness and improve performance while solving a monotonous cognitive task requiring sustained attention and vigilance.

The Effects of Mobile-Phone Electromagnetic Fields on Brain Electrical Activity: A Critical Analysis of the Literature

“…Even though the wavelength of mobile-phone radiation is such that the brain of a normal user is in the near field of the phone's antenna (OSHA, 1990), a long-standing practice has been to use the plane-wave approximation (E 2 /377) Becker, 1982a, 1982b) and express the applied field in terms of a power density. Many investigators eschewed use of a Maxwellian variable, and instead listed only a specific absorption rate (Hietanen et al, 2000;Croft et al, 2008;Fritzer et al, 2007;Kleinlogel et al, 2008aKleinlogel et al, , 2008bWagner et al, 1998, 2000, Borbe´ly et al, 1999Huber et al, 2003;Maby et al, 2004Maby et al, , 2005Maby et al, , 2006Freude et al, 1998;Hamblin et al, 2006;Jech et al, 2001;Perentos et al, 2007;Regel et al, 2007aRegel et al, , 2007bHuber et al, 2000Huber et al, , 2002Loughran et al, 2005;Hung et al, 2007;Stefanics et al, 2007;Parazzini et al, 2007;Hinrichs and Heinze, 2004), as if it were true that the extent of the ability of the EMF to heat water was a proper description of their independent variable-it was not. The specific absorption rate has been adopted by regulatory agencies to compare the outputs of mobile phones, but no authority has used it to explain their neurophysiological consequences.…”

“…In a typical mobile-phone EMF experiment 217 radio-frequency pulses per second were applied to the subject, resulting in 434 electrode spike potentials per second. Because most of the studies also applied a low-frequency magnetic field in addition to the radio-frequency EMFs (Reiser et al, 1995;Carrubba et al, 2007a;Ro¨schke and Mann, 1997;Hietanen et al, 2000;Croft et al, 2002Croft et al, , 2008D'Costa et al, 2003;Curcio et al, 2005;Mann and Ro¨schke, 1996;Wagner et al, 1998Wagner et al, , 2000Lebedeva et al, 2000Lebedeva et al, , 2001Maby et al, 2004Maby et al, , 2005Maby et al, , 2006Bak et al, 2003;Eulitz et al, 1998;Freude et al, 1998Freude et al, , 2000Hamblin et al, 2004Hamblin et al, , 2006Jech et al, 2001;Krause et al, 2000aKrause et al, , 2000bKrause et al, , 2004Krause et al, , 2006Krause et al, , 2007, the problem of artifacts was compounded because the magnetic field from the battery current also produces 434 spikes/s. No investigator removed these artifacts prior to decomposing the recorded signal into its component frequencies.…”

“…A variety of verbal formulas were used to express a conclusion that mobile-phone EMFs had altered brain electrical activity. As examples, investigators asserted that EMFs caused ''yclear tendenciesy'' (Hinrikus et al, 2004), ''yinduced but not evoked brain potential activityy'' (Eulitz et al, 1998), ''ya significant decrease of slow potentialsy'' (Freude et al, 2000), ''yimprove(d) performancey'' (Jech et al, 2001), ''ya gender-related influence on brain activityy'' (Papageorgiou et al, 2004), ''yaltered (desynchronization) responsesy'' (Krause et al, 2000b), ''yeffects on brain oscillatory responsesy'' (Krause et al, 2006), a ''(modified)ysleep electroencephalogramy'' (Loughran et al, 2005), ''ya dose-dependent increase of powery'' (Regel et al, 2007b). The formulas were misleading because they obscured the fact that the associated level of chance was greater than 5%.…”

“…They opined regarding the reasons for their failure to support their hypothesis, but they did not acknowledge that the most probable reason was that the effects of EMFs on brain electrical activity are nonlinearly related to the field, whereas they used linear analysis (ANOVAs). Jech et al (2001) investigated the effects of EMFs on event-related potentials recorded during EMF exposure, and on baseline EEG recorded after exposure. The subjects, who were narcoleptics, were either exposed or sham-exposed on successive days.…”

New Device Against Non-Thermal Effects from Mobile Telephones

“…Neurons can respond to electromagnetic fields included microwave stimuli (Kholodov and Lebedeva, 1979;Beasond and Semm, 2002). It has also been pointed out that acute mobile telephone operation affects neural function in humans (Jech et al, 2001;Croft, 2002a).…”