Increasing familiarity with the heartbeat counting task does not affect performance

Background: Interoception is typically defined as the processing and perception of internal signals. A common evaluation of interoceptive abilities is via the perception of heartbeats, applied through the heartbeat counting task, during which participants count their heartbeats over a period of time. It has been argued recently, however, that performance in this task may reflect processes other than cardiac sensation.Objective: This study therefore aimed to: 1) observe heartbeat counting task performance changes across multiple repetitions of the task; and 2) compare performance in the heartbeat counting task with that for a visual counting task, designed to mirror the former, to investigate generalised propensities for how uncertain stimuli are reported.Methods: Seventy-nine healthy participants performed seven blocks each of the heartbeat and visual counting tasks. Performance in each task was compared across blocks to identify any increase or decrease in derived scores. Heartbeat counting and visual counting tasks performances were then correlated. These analyses were preregistered at https://doi.org/10.17605/OSF.IO/GWAB7.Results: Heartbeat counting task performance did not change over the seven blocks. In contrast, changes in scores derived from the visual counting task did differ across blocks, with performance degrading over time. A positive correlation was observed between the participant’s performance in the two tasks (Spearman’s ρ = .27).Conclusion: Heartbeat counting task performance is stable across repetitions of the task. This suggests that performance does not increase as one becomes familiar with the task. A positive correlation between the heartbeat counting task and the visual counting task may point to a general propensity in counting uncertain stimuli across exteroceptive and interoceptive domains, raising questions about the interpretation of the heartbeat counting task as a measure of interoception.