Effects of heartbeat feedback on beliefs about heart rate and heartbeat counting: a cautionary tale about interoceptive awareness.

Heartbeat counting improves after exposure to heartbeat feedback either because feedback trains individuals to detect heartbeats or updates their knowledge/beliefs about heart rate. These possibilities were examined by assessing heartbeat counting, in different postures and following exercise, before and after exposure to immediate and delayed heartbeat feedback. Immediate and delayed feedback provided accurate information about heart rate and, therefore, either could update beliefs about heart rate. However, only immediate feedback marked each ventricular contraction and, thereby, could train participants to detect the beating of the heart by focusing attention on relevant internal sensations. Exposure to immediate and delayed feedback resulted in similar, significant increases in the accuracy of heartbeat counting, indicating that the feedback effect was mediated by non-sensory processes rather than by training participants to detect heartbeat sensations. The current findings demonstrate that the heartbeat counting task is not a valid method to assess cardioception.