Interoception modulates the self-prioritization effect

Self-relevant information is processed faster and more accurately than non-self-relevant information. Such a bias is developed even for newly associated information with the self, also known as the self-prioritization effect (SPE). Interoception, which refers to the overall processing of information from inside the body, is crucial for self-relevant processing; however, little is known about its role in SPE. In this study, we investigated the relationship between the magnitude of SPE and interoceptive accuracy (IAc), defined as an individual’s ability to accurately perceive one’s own interoceptive state. Additionally, to explore the causal relationship, we measured SPE by presenting self- or non-self-relevant stimuli based on the participant's cardiac cycle in the shape-label matching task. We demonstrated that IAc was negatively correlated with the magnitude of SPE in terms of discrimination of the relevance of the stimuli. In addition, a correlation was observed only when the stimuli were presented during cardiac systole. Furthermore, IAc was negatively correlated with the processing of self-relevant stimuli but not with non-self-relevant stimuli. Our findings suggest that individuals with high IAc were less able to discriminate whether an external neutral stimulus was self-relevant when the stimulus was presented at systole. Our results may reflect the tendency to recognize the self-relevance of stimuli based on interoception in individuals with high IAc. Since the present study used geometric shapes, which are not easily recognized as stimuli that can induce changes in the interoception, individuals with high IAc assigned less self-relevance to the stimuli, resulting in weaker SPE. From this perspective, we further discussed the conditions that lead to stronger SPE in individuals with high IAc, in contrast to the present study results.

Clarifying the relationship between alexithymia and subjective interoception

The long-standing hypothesis that emotions rely on bodily states is back in the spotlight. This has led some researchers to suggest that alexithymia, a personality construct characterized by altered emotional awareness, reflects a general deficit in interoception. However, tests of this hypothesis have relied on heterogeneous assessment methods, leading to inconsistent results. To shed some light on this issue, we administered a battery of self-report questionnaires of interoception and alexithymia to three samples from Italy, the U.S., and Singapore (N = 814). Correlation and machine learning analyses showed that alexithymia was associated with deficits in both subjective interoceptive accuracy and attention. Alexithymics’ interoceptive deficits were primarily related to difficulty identifying and describing feelings. Interoception showed a weaker association with externally-oriented thinking as operationalized by the Toronto Alexithymia Scale (TAS-20) and no association with the affective dimension of alexithymia later introduced by the Bermond-Vorst Alexithymia Questionnaire (BVAQ). We discuss our results with reference to the theoretical and psychometric differences between these two measures of alexithymia and their shortcomings. Overall, our results support the view that interoceptive deficits are a core component of alexithymia, although the latter cannot be reduced to the former.

Interoception and social cognition in chronic low back pain: a common inference disturbance? An exploratory study

Aim: Lower interoceptive abilities are a characteristic of chronic pain conditions. Social support plays an important role in chronic low back pain (cLBP) but social cognitive skills have rarely been investigated. This study aimed to characterize interoceptive and social cognitive abilities in cLBP and to study the relationship between both domains that have been brought closer together by brain predictive coding models. Materials & methods: Twenty-eight patients with cLBP and 74 matched controls were included. Interoceptive accuracy (Heart Beat Perception Task), sensibility/awareness (Multidimensional Assessment of Interoceptive Awareness) and mental-states inference abilities (Mini-Social Cognition and Emotional Assessment) were assessed. Results: cLBP Patients had lower interoceptive accuracy and mentalizing performance. Conclusion: Less efficient interoceptive accuracy and mentalizing abilities were found in cLBP patients without correlation between these performances.

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

Perception of internal bodily sensations or interoception has recently been studied under a predictive coding framework. In this framework, the brain utilizes both top-down prediction and bottom-up prediction error signals to determine the content of the perception through inferences regarding the cause of the ongoing sensation. Particularly, interoception and other exteroceptive sensory modalities are considered to share an integrated, intertwined process of inference. Thus, it is possible that exteroceptive stimuli interfere with the inference of interoception. Hence, we investigated whether auditory stimuli disrupted interoceptive inference that resulted in diminished awareness of interoception. Thirty healthy volunteers performed the heartbeat counting task with and without distractor sounds. The psychophysiological traits that would reflect the individual differences in prior prediction signals of interoception were measured as the high-frequency component of the heart rate variability (HF-HRV) at rest and trait interoceptive sensibility. The results showed that the auditory distractor diminished objective interoceptive accuracy, subjective confidence in interoception, and the intensity of the heartbeat, suggesting disrupted interoceptive inference under external stimuli. Importantly, individual differences in the distractor effect were modulated by both the HF-HRV and tendency to worry about bodily states. These findings support and extend the predictive coding account of interoception by suggesting that interoceptive inference could be disrupted by external stimuli and that such disruption may be modulated by a difference in prior predictions and its precision regarding interoception.

When the Body Knows: Interoceptive Accuracy Enhances Physiological But Not Explicit Differentiation Between Liars and Truth-Tellers

Recent research suggests that people experience distinct physiological reactions to lies versus truths. It is unclear, however, if this experience is incorporated into greater truth-lie judgment accuracy. We hypothesized individuals with high interoceptive accuracy—those with greater access to bodily experiences and stronger physiological responses to emotional stimuli—might be particularly likely to accurately discriminate high-stakes, emotional lies and truths. Participants (n = 71) completed two study sessions: the first assessed their interoceptive accuracy with heartbeat detection measures and the second assessed their deception detection ability while measuring their physiological reactivity. Interoceptive accuracy was associated with a greater difference in vasoconstriction to liars (vs. truth-tellers), suggesting that interoception was positively associated with physiological sensitivity to deception. Interoceptive accuracy, however, was unrelated to deception detection accuracy. While better interoception provides enhanced physiological signals that could better discriminate lies from truths, it does not improve deception detection accuracy.

Effects of a Single Yoga Session on Cardiac Interoceptive Accuracy and Emotional Experience

Background: There is an increasing body of research supporting the idea that cardiac interoceptive accuracy (IAc) can be improved by training. Findings concerning the effects of a single yoga session on IAc and the related construct emotional experience are sparse. The aim of this study was to examine if a single yoga session increases IAc and improves emotional experience. Methods: 137 students were randomly assigned to a 20-min yoga session (n = 47), an endurance session (n = 46), or an inactive control condition (n = 44). IAc and emotional experience were assessed before and after the sessions. Results: There were no significant changes in IAc, or positive and negative affect. IAc at baseline and the change in positive effect were found as predictors for IAc after the yoga session. Conclusion: A 20-min yoga session seems to be not applicable to improve IAc and emotional experience. Future studies should investigate long-term interventions and diverse healthy and clinical populations.

Do interoception and attending to the upper limbs affect body ownership and body representation in the grasp illusion?

Passively grasping an unseen artificial finger induces ownership over this finger and an illusory coming together of one’s index fingers: a grasp illusion. Here we determine how interoceptive ability and attending to the upper limbs influence this illusion. Participants passively grasped an unseen artificial finger with their left index finger and thumb for 3 min while their right index finger, located 12 cm below, was lightly clamped. Experiment 1 (n = 30) investigated whether the strength of the grasp illusion (perceived index finger spacing and perceived ownership) is related to a person’s level of interoceptive accuracy (modified heartbeat counting task) and sensibility (Noticing subscale of the Multidimensional Assessment of Interoceptive Awareness). Experiment 2 (n = 30) investigated the effect of providing verbal or tactile cues to guide participants’ attention to their upper limbs. On their own, neither interoceptive accuracy and sensibility or verbal and tactile cueing had an effect on the grasp illusion. However, verbal cueing increased the strength of the grasp illusion in individuals with lower interoceptive ability. Across the observed range of interoceptive accuracy and sensibility, verbal cueing decreased perceived index spacing by 5.6 cm [1.91 to 9.38] (mean [95%CI]), and perceived ownership by ∼3 points on a 7-point Likert scale (slope -0.93 [-1.72 to -0.15]). Thus, attending to the upper limbs via verbal cues increases the strength of the grasp illusion in a way that is inversely proportional to a person’s level of interoceptive accuracy and sensibility.