Comparison of three behavioral cardioception tasks and heartbeat evoked potentials in the same group of healthy volunteers

Cardioception is the ability of the central nervous system to process signals from the heart. Methods for determining cardioception are still under discussion. In the present study, we considered metrics for cardiac interoceptive accuracy (CA) assessments in three behavioral cardioception tasks - (1) the heartbeat tapping (HTT), (2) the heartbeat discrimination (HDT), and (3) the heartbeat counting (HCT) - and heartbeat evoked potentials (HEP) recorded by an electroencephalography during resting state and the tasks. The study included forty-eight healthy volunteers (25 females, 36 ± 7 age). CA in the HTT assessed using various metrics, except for the metric based on the circular variation between heartbeat and pressing time, positively correlated both with each other and with the metric in the HCT. The HDT showed no correlation with the other tasks. However, none of the metrics showed a clear advantage over the others in their association with the neurophysiological marker of interoception, the mean HEP amplitudes, during task performance or at rest. During all three tasks, the HEP amplitudes (1) did not differ between individuals with high and low CA metrics, (2) was not different from the HEP amplitudes during the resting state, (3) was lower during the HDT compared to the HCT. Thus, our results contribute to the debate on the interaction between behavioral cardioception tasks and the HEP.