Every decision is accompanied by uncertainty and sometimes even the feeling of having made a mistake. As a researcher, we can ask for the confidence of a decision after the decision has been made and present participants with a so-called confidence scale ranging from very certain to very uncertain: "So you think the traffic light was green but how certain are you?" Similarly, we can ask participants to detect their own errors or mistakes: "If you think you made a mistake please push this particular button". These two meta-cognitive processes (cognition about cognition) are typically investigated in isolation but we will investigate them together. We will test whether decision confidence and error awareness are based on the same internal signals. There is already some support for the idea that we base our subjective evaluation on our own perceived heartbeat, where a decelerated heartbeat is indicative of uncertainty or mistakes. We will give false cardiac feedback by means of tactile stimulation and investigate how this influences our metacognition. The project will increase our understanding of the relationship between confidence and error awareness and the role of internal signals in shaping these metacognitive experiences.