This exploratory study aimed to investigate the relationship between interoceptive sensibility and quality of consciousness in individuals with insomnia disorder, in order to understand how the modulation of internal states may contribute to modifying the experience of consciousness during sleep difficulties. A total of 37 patients with insomnia disorder (mean age = 46.05 ± 18.16) and 41 healthy good sleepers (mean age = 50.2 ± 12.99) underwent a psychometric sleep and interoceptive sensibility assessment, using Insomnia Severity Index (ISI), Pittsburgh Sleep Quality Index (PSQI), and Multidimensional Assessment of Interoceptive Awareness (MAIA). Moreover, patients with insomnia disorder also completed a quality of consciousness evaluation, using the Phenomenology of Consciousness Inventory (PCI). Patients with insomnia disorder exhibited heightened interoceptive sensibility, particularly in noticing body sensations (p < 0.0001) and emotional awareness (p = 0.032), along with diminished abilities in attention regulation (p = 0.040), not-worrying (p = 0.001), and trusting (p = 0.002). Furthermore, correlations between interoceptive sensibility and multiple aspects of the consciousness state during the insomnia night were identified. Specifically, higher emotional awareness was linked to a 2.49-fold increase in the likelihood of subjectively experiencing altered consciousness states during insomnia. The study sheds light on the relationship between interoceptive sensibility and the subjective state of consciousness during insomnia, emphasising the importance of exploring and considering interoception as part of the therapeutic process for insomnia disorder. Given the exploratory nature of the study and the increased risk of type-I error from numerous correlations, the results should be interpreted with caution. Further research is needed to validate and confirm their robustness.

Attending to heartbeats for interoceptive awareness initiates distinct electrophysiological responses synchronized with the R-peaks of an electrocardiogram (ECG), such as the heartbeat-evoked potential (HEP). Beyond HEP, this study proposes heartbeat-related spectral perturbation (HRSP), a time-frequency map of the R-peak locked electroencephalogram (EEG), and explores its characteristics in identifying interoceptive attention states using a classification approach. HRSPs of EEG brain components specified by independent component analysis (ICA) were used for the offline and online classification of interoceptive states. A convolutional neural network (CNN) designed specifically for HRSP was applied to publicly available data from a binary-state experiment (attending to self-heartbeats and white noise) and data from our four-state classification experiment (attending to self-heartbeats, white noise, time passage, and toe) with diverse input feature conditions of HRSP. From the dynamic state perspective, we evaluated the primary frequency bands of HRSP and the minimal number of averaging epochs required to reflect changing interoceptive attention states without compromising accuracy. We also assessed the utility of group ICA and models for classifying HRSP in new participants. The CNN for trial-by-trial HRSP with actual R-peaks demonstrated significantly higher classification accuracy than HRSP with sham, i.e., randomly positioned, R-peaks. Gradient-weighted class activation mapping highlighted the prominent role of theta and alpha bands between 200-600 ms post-R-peak-features absent in classifications using sham HRSPs. Online classification benefits from employing a group ICA and classification model, ensuring reliable accuracy without individual EEG precollection. These results suggest HRSP\'s potential to reflect interoceptive attention states, proposing transformative implications for clinical applications.

OBJECTIVE: Pregnancy is a sensitive period of development in adult life characterized by massive changes in physical, emotional, and cognitive function. Such changes may be adaptive, e.g., facilitating adjustment to physical demands, but they may also reflect or contribute to risks inherent to this stage of life, e.g., prenatal depression. One cognitive ability that may undergo change during pregnancy and contribute to mental wellness is interoception - the ability to perceive, integrate, and model sensory information originating from the body. Strong interoceptive abilities are associated with lower rates of depression in non-pregnant adult populations, and interoception is generally weaker in individuals at higher risk for depression, for example, exposure to early life adversity (ELA). In the present online, cross-sectional study, we investigated whether interoception in pregnant women differed based on histories of ELA, in ways that increased their relative risk for prenatal depression symptoms.
METHODS: The pregnant individuals were in the second trimester of their first pregnancy and were compared to a group of nulliparous, non-parenting women.
RESULTS: Previous exposure to ELA significantly moderated pregnancy-related differences in self-reported interoception (interoceptive sensibility). A further moderated-mediation analysis revealed that the extent to which interoceptive sensibility buffered against depressive symptoms was conditional on ELA exposure, suggesting more ELA is associated with lower interoceptive sensibility during pregnancy, which increased prenatal depression risk.
CONCLUSIONS: Together this work suggests that levels of interoception during pregnancy are sensitive to previous adversity exposure. It also suggests that interoceptive-focused interventions for preventing/treating prenatal depressive symptoms in high-risk women may be worth exploring.

The enfacement illusion is a facial version of the rubber hand illusion, in which participants experience tactile stimulation of their own faces synchronously with the observation of the same stimulation applied to another\'s face. In previous studies, participants have reported experiencing an illusory embodiment of the other\'s face following synchronous compared to asynchronous stimulation. In a series of three experiments, we addressed the following three questions: (i) how does similarity between the self and the other, operationalized here as being of the same or different gender to the other, impact the experience of embodiment in the enfacement illusion; (ii) does the experience of embodiment result from alterations to the self-concept; and (iii) is susceptibility to the experience of embodiment associated with interoceptive processing, i.e. perception of the internal state of the body? Results indicate that embodiment is facilitated by the similarity between the self and the other and is mediated by the incorporation of the other into the self-concept, but sensitivity to one\'s own internal states does not impact upon embodiment within the enfacement illusion. This article is part of the theme issue \'Minds in movement: embodied cognition in the age of artificial intelligence\'.

BACKGROUND: The intricate pathophysiological mechanisms of major depressive disorder (MDD) necessitate the development of comprehensive early indicators that reflect the complex interplay of emotional, physical, and cognitive factors. Despite its potential to fulfill these criteria, interoception remains underexplored in MDD. This study aimed to evaluate the potential of interoception in transforming MDD\'s clinical practices by examining interoception deficits across various MDD stages and analyzing their complex associations with the spectrum of depressive symptoms.
METHODS: This study included 431 healthy individuals, 206 subclinical depression individuals, and 483 MDD patients. Depressive symptoms and interoception function were assessed using the PHQ-9 and MAIA-2, respectively.
RESULTS: Interoception dysfunction occurred in the preclinical phase of MDD and further impaired in the clinical stage. Antidepressant therapies showed limited efficacy in improving interoception and might damage some dimensions. Interoceptive dimensions might predict depressive symptoms, primarily enhancing negative thinking patterns. The predictive model based on interoception was built with random split verification and demonstrated good discrimination and predictive performance in identifying MDD.
CONCLUSIONS: Early alterations in the preclinical stage, multivariate associations with depressive symptoms, and good discrimination and predictive performance highlight the importance of interoception in MDD management, pointing to a paradigm shift in diagnostic and therapeutic approaches.

Blindness is associated with heightened sensory abilities, such as improved hearing and tactile acuity. Moreover, recent evidence suggests that blind individuals are better than sighted individuals at perceiving their own heartbeat, suggesting enhanced interoceptive accuracy. Structural changes in the occipital cortex have been hypothesized as the basis of these behavioral enhancements. Indeed, several studies have shown that congenitally blind individuals have increased cortical thickness within occipital areas compared to sighted individuals, but how these structural differences relate to behavioral enhancements is unclear. This study investigated the relationship between cardiac interoceptive accuracy and cortical thickness in 23 congenitally blind individuals and 23 matched sighted controls. Our results show a significant positive correlation between performance in a heartbeat counting task and cortical thickness only in the blind group, indicating a connection between structural changes in occipital areas and blind individuals\' enhanced ability to perceive heartbeats.

The perception of signals from within the body, known as interoception, is increasingly recognized as a prerequisite for physical and mental health. This study is dedicated to the development of effective technological approaches for enhancing interoceptive abilities. We provide evidence of the effectiveness and practical feasibility of a novel real-time haptic heartbeat supplementation technology combining principles of biofeedback and sensory augmentation. In a randomized controlled study, we applied the developed naturalistic haptic feedback on a group of 30 adults, while another group of 30 adults received more traditional real-time visual heartbeat feedback. A single session of haptic, but not visual heartbeat feedback resulted in increased interoceptive accuracy and confidence, as measured by the heart rate discrimination task, and in a shift of attention toward the body. Participants rated the developed technology as more helpful and pleasant than the visual feedback, thus indicating high user satisfaction. The study highlights the importance of matching sensory characteristics of the feedback provided to the natural bodily prototype. Our work suggests that real-time haptic feedback might be a superior approach for strengthening the mind-body connection in interventions for physical and mental health.

BACKGROUND: In psychotherapy, physical exercise has gained recognition and extensive research attention, displaying promise in various mental health conditions. Practices such as yoga, tai chi, and the Feldenkrais Method® (FM) have also emerged as effective mental health interventions.
OBJECTIVE: This systematic literature review (SLR) explores the applicability of FM, a somatic practice, in psychiatric care and emotional regulation, as it emphasizes the interplay between bodily sensations, action patterns, and cognitive processes.
METHODS: Following PRISMA guidelines, a systematic search was conducted across selected databases from 2000 to 2022, identifying 14 articles, including randomized controlled trials, cohort studies, narrative papers, and SLRs. Thematic analysis was conducted.
RESULTS: The findings indicate global FM adoption, primarily in studies related to pain conditions, musculoskeletal disorders, and neurological disorders. Various measures were used, covering quality of life, psychological dimensions, self-image, self-efficacy, mindfulness, and interoception. However, direct application of FM in psychiatric care remains limited, with few studies addressing psychological issues. This review calls for more comprehensive investigations of FM\'s potential in psychiatric contexts, advocating precise measures and a dimensional approach to assessing psychological outcomes.
CONCLUSIONS: Further research is needed to explore the application of FM in psychiatric care. While existing research suggests potential benefits, especially in enhancing body awareness and emotional regulation, robust studies are necessary to establish its effectiveness in treating specific mental health conditions. This review serves as the foundation for future research into the potential role of FM in enhancing psychiatric care and emotional well-being.

BACKGROUND: Our brain uses interoceptive signals from the body to shape how we perceive emotions in others; however, whether interoceptive signals can be manipulated to alter emotional perceptions is unknown. This registered report examined whether alcohol administration triggers physiological changes that alter interoceptive signals and manipulate emotional face processing.
METHODS: Participants (n=36) were administered an alcohol or placebo beverage. Cardiovascular physiology (Heartrate variability, HRD) was recorded before and after administration. Participants completed a behavioral task in which emotional faces were presented in synchrony with different phases of the cardiac cycle (i.e., systole/diastole) to index of how interoceptive signals amplify them.
OBJECTIVE: We hypothesized that alcohol administration would disrupt the cardiac amplification of emotional face processing. We further explored whether this disruption depended on the nature and magnitude of changes in cardiovascular physiology after alcohol administration.
RESULTS: We observed no main effects or interactions between alcohol administration and emotional face processing. We found that HRV at baseline negatively correlated with the cardiac amplification of emotional faces. The extent to which alcohol impacted HRV negatively correlated with the cardiac amplification of angry faces.
CONCLUSIONS: This registered report failed to validate the primary hypotheses but offers some evidence that the effects of alcohol on emotional face processing, if any, could be mediated via changes in basic physiological signals that are integrated via interoceptive mechanisms. Results are interpreted within the context of interoceptive inference and could feed novel perspectives for the interplay between physiological sensitivity and interoception in the development of drug-related behaviors.

OBJECTIVE: Affect regulation theories of eating disorders (ED) posit that negative affect increases in the hours before and decreases following disordered eating behaviors (DEBs) in daily life, yet findings from studies assessing affective changes post-DEBs are mixed. This inconsistency may be due to the previously unassessed role of other transdiagnostic processes in these associations, such as interoception (the ability to sense and integrate information from bodily sensations). To address this research gap, the present study examined whether different interoception dimensions moderated negative affect trajectories surrounding DEBs in the natural environment.
METHODS: 150 women with ED pathology (Mage = 21.0, SD = 4.1) completed 4 surveys targeting affect and DEBs each day for a 10-day ecological momentary assessment period. Polynomial multilevel models examined negative affect trajectories pre- and post-DEBs (dietary restriction, overeating, loss of control eating), and whether these trajectories varied based on daily interoception dimensions (not distracting, self-regulation, body listening and trust).
RESULTS: Negative affect increased prior to loss of control eating-but not dietary restriction or overeating-and decreased following all DEBs. Further, the magnitude of the decrease in negative affect that emerged post-dietary restriction decreased in strength as daily \"not distracting\" interoception increased. The other interoception dimensions did not moderate negative affect trajectories surrounding DEBs.
CONCLUSIONS: Allowing oneself to experience (vs. distract from) uncomfortable bodily sensations may weaken affect dysregulation processes that follow dietary restriction in daily life and are theorized to maintain DEBs. These results provide insight that may strengthen EDs theories, research, and inform interoception-focused interventions.