Objectives
The goals of the current study were to investigate: (i) how the manipulation of psychophysiological state (stress vs. relaxation) would influence heartbeat detection performance in a laboratory environment and (ii) whether interoceptive accuracy had a relationship with symptom reporting.

Method
Forty participants (20 males) performed a stressor (a demanding mental arithmetic task) and a relaxation exercise during two counterbalanced sessions, both of which included baseline (control) conditions. Performance of both tasks was interspersed with a heartbeat detection task, i.e., a two-choice Whitehead paradigm. Data were collected from subjective mood scales as well as the electrocardiogram.

Results
Both stress and relaxation conditions had the anticipated influence on subjective mood. There was no effect of stress or relaxation on heartbeat detection accuracy for male participants. However, the heartbeat detection accuracy of female participants showed a significant decline during the stressor condition. There was evidence that lower mean heart rate tended to improve heartbeat detection performance. A regression analysis revealed that two traits from the Body Perception Questionnaire (autonomic reactivity and body awareness) predicted heartbeat detection accuracy but not in the expected direction.

Conclusions
The study provided evidence of a gender-specific decrement of heartbeat detection accuracy due to a laboratory stressor. However, the relevance of this finding for health psychology may be limited, as interoceptive accuracy had no significant relationship with symptom reporting.