Validation Of A Method For Assessing Cardiac Sensitivity And New Findings On The Functional Significance Of Heartbeat-Evoked Potentials

Bodily perception is becoming increasingly important to neuropsychological theories. If we are to measure such individual interoceptive processes objectively and validly, we need an appropriate method.This study tests the validity of an evaluation method of motor heartbeat detection tasks, which accounts for valid reactions (hits) and invalid reactions in order to obtain a measure of cardiac sensitivity.This method is based on the signal-detection theory, and its sensitivity index (d') is intended to map actual cardiac sensitivity independently of the individual response bias. Two questions were central: (1) Is it possible to identify valid reactions in the heartbeat evoked potential (HEP) by means of a P300 component? (2) Is d' a valid indicator of cardiac sensitivity? The results of the current study support both assumptions.Thus, the (visceroceptive) P300 proves to be an indicator of heartbeat detection, and d" functions as a parameter for separating good from bad heartbeat detectors - and in doing so it performs even better than a (comparatively good) conventional parameter.The study validates d` as a measure of cardiac sensitivity and provides new insights into the functional significance of the HEP as a signature of cortical processing of afferent cardiovascular signals.