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.
Interoception describes the perception of symptoms and sensations that originate within the body [1] and [2]. Interoceptive perception of internal change functions as the first stage in the process of symptom detection [3] and [4]. Interoceptive accuracy (IA) is also relevant for specific clinical conditions, i.e., there is evidence that IA is higher for sufferers of anxiety disorders and panic attacks [5] and [6].
Laboratory-based assessment of IA typically involves the subjective appraisal of ongoing physiological activity, e.g., sensitivity to temporal characteristics of heart rate [7]. A number of standard protocols have been developed and refined for the measurement of heartbeat detection accuracy [8], [9] and [10], e.g., the Whitehead procedure [7], which requires participants to discriminate between synchronous (“true”) and asynchronous (“false”) feedback of the heartbeat, presented aurally as a series of tones [11] and [12].
With respect to symptom perception within a health context, it has been argued that high IA is associated with hypersensitivity to bodily sensations and a tendency to overreport physical symptoms [13] and [14]. The evidence to support this hypothesis is mixed. A study by Aronson et al [15] found no association between IA using the Whitehead procedure and scores on the Somatosensory Amplification Scale (SSAS) [16], i.e., the SSAS is associated with hypochondrias and increased symptom reporting. A recent neuropsychological study conducted by Critchley et al [17] reported a positive association between: (a) activity in the right anterior insula and IA on the Whitehead task, (b) IA and the size of the right anterior insula (i.e., local gray matter volume) and (c) local gray matter volume in the right anterior insula and a subjective measure of body awareness [18]. This study pointed to a degree of convergence between neurological and subjective traits associated with interoception but provided no evidence for any direct association between subjective body awareness and IA.
If IA is indirectly associated with symptom overreporting via a personality trait or neurological substrate, this relationship may be complicated by the influence of transient changes at the autonomic level. Increased sympathetic activation due to physical manipulation or psychological variables may moderate interoceptive perception by acting directly on the autonomic system. For example, increased stroke volume due to a physical manipulation (a tilt-table) tends to increase the accuracy of heartbeat perception [19] and [20]. The influence of transient psychological factors such as anxiety and emotional activation has been explored via a number of correlational studies [17], [21], [22], [23] and [24], which demonstrated that increased emotional activation and subjective changes in negative affect/anxiety may improve IA.
It is postulated that physiological reactivity to everyday anxiety or stress may influence the process of symptom perception by acting directly on interoceptive awareness. Anxiety and negative affect have distinct autonomic concomitants [25], which may raise IA and provoke the tendency towards overreporting or symptom amplification previously noted by Barsky and Borus [26] and Pennebaker [14]. If proven, this causal chain could potentially beget a vicious spiral wherein anxiety provokes increased IA, which amplifies symptom detection and severity, and subsequently raises the level of anxiety experienced by the individual.
The purpose of the current study is to test this hypothesis by prospectively manipulating levels of anxiety in a laboratory environment and assessing any subsequent effects on heartbeat perception accuracy. The study will also investigate any possible correlational relationships between IA, individual traits and symptom reporting.
