Study type: Medical/biological study (experimental study, theoretical study)

Analysis of auditory evoked potential parameters in the presence of radiofrequency fields using a support vector machines method. med./bio.

Published in: Med Biol Eng Comput 2004; 42 (4): 562-568

Aim of study (acc. to author)

To study global system for mobile communications (GSM) cellular phone radiofrequency effects on human cerebral activity. The work was based on the investigation of auditory evoked potentials recorded from healthy humans and epileptic patients. Ten variables measured from auditory evoked potentials were employed in the design of a supervised support vector machines classifier.

Endpoint

Exposure

Exposure Parameters
Exposure 1: 900 MHz
Modulation type: pulsed
  • SAR: 1.4 W/kg average over mass (10 g) (maximum emission phase)

Exposure 1

Main characteristics
Frequency 900 MHz
Type
Additional info GSM phone, frequency assumed (not indicated!)
Modulation
Modulation type pulsed
Exposure setup
Exposure source
Chamber The subject reclined on a chair in a soundproof Faraday screened room.
Setup Two 24-ms sound stimuli of 500 Hz and 1 kHz in random order (250 times each) were heard through the phone once every second. The experimental sessions consisted of four phases: no RF emission, minimal RF emission, maximum RF emission and again minimal RF emission.
Additional info Every healthy subject took part in two sessions several days apart (with the phone on the right or the left ear). A third session was either supplementary or sham. Epileptic patients had only two sessions (EMF or sham on the side affected by the disease). The type of session was not known to the subject. In this study only phones on the right ear were considered.
Parameters
Measurand Value Type Method Mass Remarks
SAR 1.4 W/kg average over mass unspecified 10 g maximum emission phase

Exposed system:

Methods Endpoint/measurement parameters/methodology

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

Main outcome of study (acc. to author)

For both groups, the N100 amplitudes were reduced under the influence of GSM radiofrequency (mean attenuation of -0.36 µV for healthy subjects and -0.60 µV for epileptic patients). Healthy subjects showed a N100 latency decrease, which could be consistent with mild, localised heating. The auditory cortical activity in humans was modified by GSM cellular phone radiofrequencies, but an effect on brain functionality has not been proven.

Study character:

Study funded by

Replication studies

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