Interoception

Processing of information about the body's internal state. Objective physiology, perception of that physiology and interpretation of its consequences are different variables.

Interpreting internal signals in relation to expectations and context. The same physiological change can receive different emotional interpretations; a computational account must specify testable predictions.

In one influential measurement framework, metacognitive correspondence between confidence and objective interoceptive performance. Other literature uses awareness more broadly, so the operational definition should be stated.

Self-reported beliefs, attention or experience concerning internal bodily signals. Questionnaire scores need not equal objective performance.

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.

Perception or estimation of one's heartbeat. A mental tracking score can depend on timing, beliefs about ordinary heart rate and response strategy as well as sensitivity to actual cardiac signals; such a score is not automatically a pure measure of interoceptive accuracy.^[ref]