Facilitation of heartbeat self-detection in a choice task.

Brener and Kluvitse (Psychophysiology 25 (1988) 554) developed a heartbeat self-detection task in which subjects are required to judge the simultaneity of heartbeat sensations and tones presented at six intervals following the onset of each ventricular contraction (0, 100, 200, 300, 400 or 500 ms). They found that most of their participants considered as simultaneous in the intervals of 100, 200 and 300 ms, in comparison to those of 0, 400 and 500 ms. In the research reported here, an adaptation of this task was administered to 32 subjects (16 men, 16 women) to see whether these interval choices would be replicated using a narrower range of values, and if task performance would be affected by the reduction in number of trials from 30 to 20. The interval values of the external stimuli with reference to the R-wave were 150, 200, 250, 300 and 350 ms. The results indicate that there was a clear choice for the intervals of 150 and 200 ms in comparison to the rest and that the performance of participants decreases after 20 trials.