Interoception refers to the ability to perceive and integrate physiological signals originating from within the body, such as heartbeat and respiration. This process involves both bottom-up and top-down. As a key neurophysiological marker of interoception, the heartbeat-evoked potential (HEP) reflects the cortical processing of cardiac signals in the brain. In this review, we first outline the neural mechanisms underlying interoception and HEP, followed by a comprehensive overview of the methodologies commonly employed in HEP research. Based on the directionality of interoceptive information flow, we categorize HEP-related experimental designs into three types: bottom-up bodily sensory input, top-down predictive perception, and top-down regulation. Additionally, we explore the clinical relevance of HEP in areas such as psychiatric disorders and cardiac-related conditions. Finally, we recommend expanding research on top-down predictive perception and top-down regulation in clinical contexts.
