Interoceptive accuracy

Performance on a specified objective test of detecting internal bodily signals. It is modality- and task-dependent; an accurate physiological recording does not guarantee a valid measure of conscious detection.

A task requiring judgments about the relation between external events and recorded heartbeats. Sensory timing and task calibration matter; it is not interchangeable with heartbeat counting.

A task comparing reported heartbeat counts with recorded beats over intervals. Prior heart-rate beliefs, timing strategies and bodily signal strength can contribute to the score.

A common score compares reported counts $C_j$ with recorded counts $N_j>0$ over $m$ intervals: $A=m^{-1}{\sum }_{j=1}^m(1-|N_j-C_j|/N_j)$. The absolute error is normalized by the recorded count. Equal reports give $A=1$, but the score does not identify the reporting strategy. The unclipped expression is at most one and can be negative for sufficiently large overcounts.

Two strategies can generate the same observations: a person detects every beat, or a person estimates the count from an expected heart rate and the interval. Whenever the estimate equals the actual count, both produce $C=N$ and score $1$. The score alone therefore lacks identifiability for the latent detection strategy. This logical counterexample does not say that all high-scoring participants use estimation.