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

## TL;DR

This study explores how expectations about electromagnetic fields influence bodily symptom perception, finding that higher anxiety and liberal response tendencies are linked to increased symptom reporting.

## Contribution

The study provides empirical evidence on how threat-related expectations influence interoceptive perception across body domains.

## Key findings

- Participants in the sham EMF group reported higher state anxiety and more symptoms during the experiment.
- Higher somatic symptom distress was associated with a more liberal interoceptive response tendency in both tasks.
- Liberal response bias is suggested as a transdiagnostic psychopathological risk factor.

## Abstract

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.