Feeling the beat: Temporal and spatial perception of heartbeat sensations

The majority of interoceptive tasks (i.e. measuring the sensitivity to bodily signals) are based upon the heartbeat sensations perception. However, temporal perception of heartbeats varies among individuals and confidence and spatial perception of heartbeats in relation to temporal judgements have not yet been systematically investigated. This study examined the perception of heartbeat sensations in both time and spatial domains, using a multi-interval heartbeat discrimination task. The relationship between these domains was investigated, as well as the contribution of mental health conditions and cardiovascular parameters. Heartbeat sensations occurred on average ~250ms after the ECG R-wave and were more frequently sampled from the left part of the chest. Participants confidence in their experience of heartbeat sensations was maximal for the 0 ms interval. Interestingly, higher confidence was related to reduced dispersion of sampling locations but we found evidence toward the absence of relationship between temporal and spatial heartbeat sensations perception, using Bayesian statistics. Finally, we found evidence toward a relationship between spatial precision of heartbeat sensations and state anxiety score, which seems independent from the cardiovascular parameters. This systematic investigation of heartbeat sensations perception provides important fresh insights, informing the mechanistic understanding of the interoceptive signaling contribution to emotion, cognition and behaviour.