Study type: Medical/biological study (experimental study)

The sensitivity of human event-related potentials and reaction time to mobile phone emitted electromagnetic fields. med./bio.

Published in: Bioelectromagnetics 2006; 27 (4): 265-273

Aim of study (acc. to author and editor)

The study aimed to replicate results of previous studies that suggest that exposure to mobile phones can affect neural activity, particularly in response to auditory stimuli.

Background/further details

Specific hypotheses were derived to test the data of a previous pilot study (see publication 10469) as well as recent positive results more generally (see publication 3601, publication 9357, and publication 11230). These hypotheses were that the N100 amplitude and N100 latency would decrease and that the P300 latency and reaction time would increase under active exposure relative to sham exposure during the auditory task.

Endpoint

Exposure

Exposure Parameters
Exposure 1: 895 MHz
Modulation type: pulsed
Exposure duration: continuous for about 21 min

Exposure 1

Main characteristics
Frequency 895 MHz
Type
Exposure duration continuous for about 21 min
Modulation
Modulation type pulsed
Pulse width 576 µs
Duty cycle 12.5 %
Repetition frequency 217 Hz
Additional info

DTX (discontinuous transmission) and APC (adaptive power control) modes were not employed.

Exposure setup
Exposure source
Chamber Participants were fitted with the EEG recording apparatus and seated in a comfortable chair 1.5 m in front of a computer monitor.
Setup A mobile phone was mounted over the temporal region (right or left side for half of the particpants) comparable to normal use (in ''touch'' position; FCC 2001 guidelines) using a plastic cradle-like apparatus. The handset's audio circuitry was disabled to avoid acoustic cues about the status of the phone. Additionally, padding was placed between the handset and its leather casing to silence buzzing sounds coming from the circuitry and to insulate against heat generated by the battery.
Sham exposure A sham exposure was conducted.
Additional info A first 21-min experimental period of sham exposure was followed, after 10 min of resting, by another 21-min period of exposure or sham exposure. A double-blind, pseudorandom, counterbalanced, crossover design was employed where subjects attended two sessions 1 week apart.
Parameters
Measurand Value Type Method Mass Remarks
power 2 W peak value - - -
power 250 mW mean - - -
SAR 0.11 W/kg average over mass measured 10 g -

Exposed system:

Methods Endpoint/measurement parameters/methodology

Investigated system:
Investigated organ system:
Time of investigation:
  • before exposure
  • during exposure
  • after exposure

Main outcome of study (acc. to author)

There was no significant difference between exposure conditions for any auditory or visual event related potential component or reaction time. As previous positive findings were not replicated, it was concluded that there is currently no evidence that acute mobile phone exposure affects these indices of brain activity.

Study character:

Study funded by

Replicated studies

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