Cardiac interoceptive learning is modulated by emotional valence perceived from facial expressions

Interoception refers to the processing of homeostatic bodily signals. Research demonstrates that interoceptive markers can be modulated via exteroceptive stimuli and suggests that the emotional content of this information may produce distinct interoceptive outcomes. Here, we explored the impact of differently valenced exteroceptive information on the processing of interoceptive signals. Participants completed a repetition-suppression paradigm viewing repeating or alternating faces. In experiment 1, faces wore either angry or pained expressions to explore the interoceptive response to different types of negative stimuli in the observer. In experiment 2, expressions were happy or sad to compare interoceptive processing of positive and negative information. We measured the heartbeat evoked potential (HEP) and visual evoked potentials (VEPs) as a respective marker of intero- and exteroceptive processing. We observed increased HEP amplitude to repeated sad and pained faces coupled with reduced HEP and VEP amplitude to repeated angry faces. No effects were observed for positive faces. However, we found a significant correlation between suppression of the HEP and VEP to repeating angry faces. Results highlight an effect of emotional expression on interoception and suggest an attentional trade-off between internal and external processing domains as a potential account of this phenomenon.