Introduction: The tendency of experiencing unpleasant symptoms in the proximity of working electric devices is called idiopathic environmental intolerance attributed to electromagnetic fields (IEI-EMF). Evidence about psychophysiological backgrounds of the phenomenon (i.e., detection ability and mechanisms of symptom generation) is not yet conclusive.
Methods: Participants of the provocation experiment were 29 individuals with self-reported IEI-EMF and 42 control persons. Participants completed questionnaires (symptom expectations, somatosensory amplification - SSAS, modern health worries radiation subscale - MHW-R), and attempted to detect the presence of 50 Hz 0.5 mT magnetic field (MF) directed to their right arm in 20 subsequent 1-min sessions. Heart rate was also recorded and various indices of heart rate variability (HF, LF/HF, SDNN) were calculated.
Results: Using the methodology of the signal detection theory, individuals with IEI-EMF as opposed to the control group showed a higher than random detection performance (d' differed slightly but statistically significantly from zero), and they used a significantly lower criterion (β value) when deciding about the presence of the MF. Detection sessions followed by correct decisions (hits or correct rejections) were characterized by higher HRV (SDNN and HF indices) than periods followed by errors (misses or false alarms). Previous expectations and affiliation to the IEI-EMF group were significant predictors of symptoms reported following exposure. IEI-EMF was closely related to MHW-R and SSAS scores.
Conclusion: Detection of MF might be possible for people with IEI-EMF to some extent. Although heightened sensibility to MFs may play a role in the development and/or in the perpetuance of the IEI-EMF phenomenon, symptoms attributed to the MF seem to be mainly of psychogenic origin.
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