Heart rate, heart rate variability, and heartbeat detection with the method of constant stimuli: slow and steady wins the race.

The literature on heartbeat detection is fraught with disagreement about appropriate methods. Some laboratories advocate the heartbeat counting method, whereas others advocate the method of constant (MCS) stimuli task. Advocates of the MCS task argue that the heartbeat counting task is confounded by expectancies of heart rate, whereas the MCS task has the virtue of assessing individual heartbeat sensations. In this paper, we present preliminary evidence that heart rate information may also influence performance on the MCS task. Heartbeat detection was predicted by decreased heart rate variability and decreased heart rate. The results suggest that the temporal patterning of heartbeats may influence performance on the MCS task.