Beware of electromagnetic fields! – Evidence for a nocebo effect in somatosensory perception by adverse television report and sham WiFi

Background: People suffering from idiopathic environmental intolerance attributed to electromagnetic fields (IEI-EMF) experience numerous non-specific symptoms that they attribute to EMF. The cause of this condition remains vague and evidence shows that psychological rather than bioelectromagnetic mechanisms are at work. We hypothesized a role of media reports in the etiology of IEI-EMF and investigated how somatosensory perception is affected. Methods: 65 healthy participants were instructed that “some people experience transient symptoms under exposure with EMF” and “some evidence exists showing enhancement of somatosensory perception by EMF”. Participants were randomly assigned to watch either a television report on adverse health effects of EMF or a neutral report. During the following experiment, participants rated stimulus intensities of tactile electrical stimuli while being exposed to a sham WiFi signal in 50% of the trials. Results: Sham WiFi exposure led to increased perception of electric stimuli in the WiFi film group, especially in participants with higher levels of somatosensory amplification. Participants of the WiFi group reported more anxiety concerning WiFi exposure than the control group and tended to perceive themselves as being more sensitive to EMF than before. Conclusions: Sensational media reports can facilitate enhanced perception of tactile stimuli in healthy participants. People tending to perceive bodily symptoms as intense, disturbing, and noxious seem most vulnerable. Receiving catastrophizing media reports might sensitize people to develop a nocebo effect and thereby contribute to the development of IEI-EMF. By promoting catastrophizing thoughts and increasing symptom-focused attention, perception might more readily be enhanced and misattributed to EMF.status: publishe