Increasing familiarity with the heartbeat counting task does not affect performance

Abstract

Background: Interoceptive awareness (IA) is the ability to perceive signals from the visceral organs of our body. One common task for evaluating IA is the heartbeat counting task (HCT), during which participants need to count their heartbeats over a period of time. It has been argued recently, however, that this task may not measure stable trait features and that it may involve non-interoceptive processes. Objective: This study therefore aimed to: 1) observe HCT performance changes across multiple repetitions of the task; and 2) compare performance in the HCT with a visual counting task (VCT), designed to mirror the HCT, to investigate generalised propensities of underreporting ambiguous stimuli. Methods: The study sampled 46 healthy subjects. Participants performed seven blocks each of the HCT and VCT. Performance in each task was compared across blocks to identify any increase or decrease in interoceptive or visual awareness. HCT and VCT performance were then correlated with each other. These analyses were preregistered at https://doi.org/10.17605/OSF.IO/GWAB7. In addition, a set of exploratory analyses were conducted based on associations with the HCT reported in the literature, including correlations with psychological questionnaires, heart-rate, and body-mass index.Results: HCT performance did not change over the seven blocks of the HCT. In contrast, changes in visual accuracy derived from the VCT did differ across blocks, with performance degrading over time. No correlation was observed between participant’s performance in the HCT and the VCT (ρ = 0.28, p = 0.056). Exploratory analyses revealed no correlation of the HCT with alexithymia, depression, and anxiety questionnaire scores, heart-rate, or body-mass index.Conclusion: HCT performance is stable across repetitions of the task. This suggests that performance does not increase as one becomes familiar with the task. The lack of correlation between the HCT and the VCT may point to different mechanisms underlying in exteroceptive and interoceptive processes or may reflect an inherent difference in their difficulty.