To study the initial contingent negative variation changes induced by 900 MHz GSM exposure in ten healthy volunteers. under three experimental conditions (randomized across the subjects and with ten minutes time interval in-between): 1) exposure to a GSM mobile phone, 2) sham exposure and 3) the phone was completely switched-off (further details see "exposure").
|Exposure duration||48 trials with intervals of 4 s to 6 s|
The initial contingent negative variation amplitude decreased and habituation increased during both exposure conditions (1 and 2) compared with condition 3, where the mobile phone was switched off. This effect was diffuse over the scalp, and there was no significant prevalence of amplitude decrease on the left side, where the cell phone was located. This evidence, limited by the low number of subjects investigated, could be explained in terms of an effect induced by both the GSM signal and the extremely low frequency magnetic field produced by battery and internal circuits.