Perception of electromagnetic fields (EMF) - pre-test of an exposure set-up

For usage in provocation experiments, two custom-made mobile exposure units were developed, which can generate extremely-low frequency magnetic fields and radio-frequency electromagnetic fields. Field types and strengths are as encountered in everyday life (e.g. from a WiFi). The units can produce repeated sham/true exposure conditions in random order selected by a computerized randomization scheme in order to achieve double blinding.

In this trial we test whether the units can indeed achieve double-blinded exposure conditions, meaning that there are no unwanted clues from which a person can tell when exposure is on, such as sounds or vibrations. 25 healthy volunteers per unit are exposed to short repeated sham and true exposures and are asked when they thought exposure was on and why they thought so. The primary outcome is the percentage of correct answers.

The exposure set-up is able to achieve truly double-blind exposure conditions.
The objective is to assess if people can tell if the exposure unit is on or off. The testing of our exposure unit aims at identifying and eliminating any potential unwanted clues as to the exposure conditions.

Directly before and after testing.

For each one of five different exposure types (electromagnetic field signals), volunteers will undergo a series of 10 randomized exposure conditions with 5 times sham and 5 times true exposure. Exposure duration will be 30 seconds, with a very short break between exposure sessions. Volunteers will be asked to indicate whether they thought the exposure was on or off.