Disrupted interoceptive awareness by auditory distractor: Difficulty inferring the internal bodily states?

Recent studies have associated interoceptive awareness, the perception of internal bodily sensations, with a predictive mechanism of perception across all sensory modalities. According to the framework, volitional attention plays a pivotal role in interoceptive awareness by prioritizing interoceptive sensations over exteroceptive ones. Consequently, it is hypothesized that the presence of irrelevant stimuli would disrupt the attentional modulation and interoceptive awareness, which remains untested. In this study, we investigated if interoceptive awareness is diminished by unrelated auditory distractors to validate the proposed perceptual framework. A total of 30 healthy human volunteers performed the heartbeat counting task both with and without auditory distractors. Additionally, we measured participant's psychophysiological traits related to interoception, including the high-frequency component of heart rate variability (HF-HRV) and trait interoceptive sensibility. The results showed that interoceptive accuracy, confidence, and heartbeat intensity decreased in the presence of distractor sound. Moreover, individuals with higher HF-HRV and a greater tendency to worry about bodily states experienced a more pronounced distractor effect on interoceptive awareness. These results provide support for the perceptual mechanism of interoceptive awareness in terms of the predictive process, highlighting the impact of relative precision across interoceptive and exteroceptive signals on perceptual experiences.

Thermosensation and emotion: Thermosensory accuracy in a dynamic thermal matching task is linked to depression and anxiety symptomatology

Interoception is related to the generation of bodily feelings and the awareness of ourselves as 'sentient beings', informing the organism about its bodily needs to guarantee survival. Previous studies have reported links among interoception, emotion processing, and mental health. For example, the alignment of interoceptive dimensions (i.e., accuracy, sensibility, awareness) can predict emotional symptoms, such as anxiety. Here, we aimed to investigate the relationship between the perception of a certain type of skin-mediated interoceptive signal, i.e., thermosensation, and self-reported depression, anxiety, and stress. One hundred seventy participants completed the Depression Anxiety Stress Scale (DASS-21) and a dynamic thermal matching task, a static temperature detection task, and a heartbeat counting task. Our results revealed that self-reported anxiety and depression were related to the perception of temperature on hairy and non-hairy skin, respectively: higher anxiety was related to better performance on the thermal matching task on the forearm, while higher depression was related to poorer performance on dynamic and static temperature tasks on the palm. Discrepancies between thermosensory accuracy and sensibility measures ('trait prediction error') were related to heightened anxiety, in line with previous studies. No significant correlations were found between DASS-21 scores and heartbeat counting accuracy. In conclusion, this study suggests that individual differences in thermosensory perception in different areas of the body are associated with self-reported anxiety and depression.

Increasing familiarity with the heartbeat counting task does not affect performance

BACKGROUND

Interoception is typically defined as the processing and perception of internal signals. A common evaluation of interoceptive abilities is the heartbeat counting task, during which participants count their heartbeats over a period of time. It has been argued recently, however, that performance in this task may reflect processes other than cardiac sensation.

OBJECTIVE

This study aimed to: 1) observe heartbeat counting task performance changes across multiple repetitions of the task; and 2) compare performance in the heartbeat counting task with that for a visual counting task to investigate generalised propensities for how uncertain stimuli are reported.

METHODS

Seventy-nine healthy participants performed seven blocks each of the heartbeat and visual counting tasks. Scores for each of the tasks were compared across blocks to identify any change in performance. Performance in the two tasks was then correlated. The study was preregistered at https://doi.org/10.17605/OSF.IO/GWAB7.

RESULTS

Heartbeat counting task performance did not change over blocks. In contrast, scores for the visual counting task reduced over time. A positive correlation was seen between performance in the two tasks (ρ(79) = .27).

CONCLUSION

Heartbeat counting task performance is stable across repetitions of the task, not changing with increasing familiarity. This suggests that non-interoceptive factors, such as beliefs, may be involved. The correlation between the heartbeat and visual counting tasks may point to a general propensity in counting uncertain stimuli across sensory domains. Together, these results raise questions about the interpretation of the heartbeat counting task as a measure of interoception.

Measuring interoception: The phase adjustment task

Interoception, perception of one's bodily state, has been associated with mental health and socio-emotional processes. However, several interoception tasks are of questionable validity, meaning associations between interoception and other variables require confirmation with new measures. Here we describe the novel, smartphone-based Phase Adjustment Task (PAT). Tones are presented at the participant's heart rate, but out of phase with heartbeats. Participants adjust the phase relationship between tones and heartbeats until they are synchronous. Data from 124 participants indicates variance in performance across participants which is not affected by physiological or strategic confounds. Associations between interoception and anxiety, depression and stress were not significant. Weak associations between interoception and mental health variables may be a consequence of testing a non-clinical sample. A second study revealed PAT performance to be moderately stable over one week, consistent with state effects on interoception.