Research has indicated that performance on heartbeat
counting tasks may be influenced by beliefs about heart
rate. Sixty male subjects were administered the Schandry
heartbeat counting task after viewing fast, slow, or no
heart rate feedback. Subjects were also administered the
Whitehead signal-detection type task. Results indicated
that subjects who received fast or no heartbeat feedback
performed better on the Schandry task than subjects who
received slow feedback. Feedback presentation did not affect
performance on the Whitehead task. These results suggest
that the Schandry task is influenced by external variables
(expectations, beliefs) beyond pure awareness of “discrete”
visceral sensations and, thus, may not be as powerful a
method for determining awareness of individual heartbeats
as some other paradigms.