Comment on "Zamariola et al., (2018), Interoceptive Accuracy Scores are Problematic: Evidence from Simple Bivariate Correlations"-The Empirical Data Base, the Conceptual Reasoning and the Analysis behind this Statement are Misconceived and do not Support the Authors' Conclusions.

A recent paper by Zamariola and colleagues is widely cited as an authority on the invalidity of the Heartbeat Counting Task as a measure of interoceptive accuracy. Given the widespread interest in this field, it is essential that papers about methods are conceptually sound. However, only one of the authors' four criticisms appears substantiated - that people count too few heartbeats. Their arguments about "simple bivariate correlations" and their finding that interoceptive accuracy and heart rate correlate, depend on 'spurious correlations' arising from the overlooked point that interoceptive accuracy is a ratio. Moreover, scrutiny of the authors' data shows that their fourth criticism (that interoceptive accuracy is lower on longer trials) is confounded by differences in mean heart rate between trials. We present data from our own labs to refute it. We draw the authors' and editors' attention to these issues and trust that they will reconsider these erroneous conclusions.