The Interoceptive Brain: Confidence Ratings and Accuracy Scores are Independently and Differently Associated With Task-Related Alpha Power During the Heartbeat Tracking Task.

Cardiac interoception is important for health and can be assessed in terms of accuracy (IAcc) and sensibility (IS), at least. While IAcc measures the correspondence between recorded and perceived heartbeats, IS means the confidence in interoceptive perceptions during the task. The present study investigated if brain activity during the heartbeat tracking task is associated with IAcc as well as IS. Specifically, we were interested if task-related power (TRP) in the alpha band (8-12 Hz), known to indicate task-specific cognitive functions such as semantic, attentional, and sensory processes, is associated with IAcc and IS, respectively. In a sample of 30 participants, we found relatively higher TRP in the alpha band over left temporal and parietal areas (vs. right) during the interoception task. Furthermore, we observed a negative association between TRP in the alpha band and IS. Lower TRP in the alpha band might indicate that more pronounced cognitive and sensory processes are linked to higher IS. Furthermore, we found a positive effect for IAcc (independent from IS), which might indicate that more internal attention during the interoception task is beneficial for IAcc. We further discuss the findings in the context of methodological issues of the heartbeat tracking task. Taken together, the pattern of findings favors the investigation of task-related IS (i.e., confidence ratings) in combination with IAcc to gain a better access to interoceptive processes and to improve our understanding of the neural underpinnings of (cardiac) interoception.