Do expectations shape interoceptive perceptions across body domains? A sham EMF study to test the predictive...

According to the principles of predictive processing theory, persistent symptom perception is largely determined by central nervous predictions on somatosensory input. Here, we examine how threat-related expectations shape predictions and interoceptive perceptions across body domains using sham EMF (electromagnetic field) exposure.

Participants (n = 113) were recruited via announcements at the university. Most participants were female (76.1 %) with a mean age of 25.12 years. Participants were divided into two groups (sham EMF on/off). Both groups completed a somatic and a cardiovascular signal detection task (SSDT, cvSDT) in pseudo-randomized order. Sensitivities and response biases were calculated. Self-reports (symptom distress, anxiety) were completed. Group effects were analysed with (M)AN(C)OVAs. In four exploratory regression models response bias and anxiety (state/trait) served as predictors for somatic symptom distress.

Participants in the sham EMF group reported significantly higher levels of state anxiety (p = .021, d = 0.44) and, trend-wise, more symptoms during the experiment (p = .065, d = 0.35). Response biases did not differ significantly between the groups (SSDT: p = .782; cvSDT: p = .743). However, higher somatic symptom distress was significantly associated with a more liberal interoceptive response tendency in both tasks in the sham EMF group (two significant models, one trend: (-0.209 ≤ βs ≤ -0.325, adjusted 0.232 ≤ R² ≤ 0.330).

A liberal approach was associated with elevated symptom experience across bodily domains and might be considered a transdiagnostic psychopathological risk factor. As research is still scarce, replication studies with valid context manipulations are essential.