Examining the association between depersonalisation traits and the bodily self in waking and dreaming.

Depersonalisation (DP) is characterized by fundamental alterations to the sense of self that include feelings of detachment and estrangement from one's body. We conducted an online study in healthy participants (n = 514) with DP traits to investigate and quantify the subjective experience of body and self during waking and dreaming, as the vast majority of previous studies focussed on waking experience only. Investigating dreams in people experiencing DP symptoms may help us understand whether the dream state is a 'spared space' where people can temporarily 'retrieve' their sense of self and sense of bodily presence. We found that higher DP traits-i.e. higher scores on the Cambridge Depersonalisation Scale (CDS)-were associated with more frequent dream experiences from an outside observer perspective (r = 0.28) and more frequent dream experiences of distinct bodily sensations (r = 0.23). We also found that people with higher CDS scores had more frequent dream experiences of altered bodily perception (r = 0.24), more frequent nightmares (r = 0.33) and higher dream recall (r = 0.17). CDS scores were negatively correlated with body boundary scores (r = - 0.31) in waking states and there was a negative association between CDS scores and the degree of trust in interoceptive signals (r = - 0.52). Our study elucidates the complex phenomenology of DP in relation to bodily selfhood during waking and dreaming and suggests avenues for potential therapeutic interventions in people with chronic depersonalisation (depersonalisation -derealisation disorder).

Heightened interoception in adults with fibromyalgia.

Previous research suggests that the processing of internal body sensations (interoception) affects how we experience pain. Some evidence suggests that people with fibromyalgia syndrome (FMS) - a condition characterised by chronic pain and fatigue - may have altered interoceptive processing. However, extant findings are inconclusive, and some tasks previously used to measure interoception are of questionable validity. Here, we used an alternative measure - the Phase Adjustment Task (PAT) - to examine cardiac interoceptive accuracy in adults with FMS. We examined: (i) the tolerability of the PAT in an FMS sample (N = 154); (ii) if there are differences in facets of interoception (PAT performance, PAT-related confidence, and scores on the Private Body Consciousness Scale) between an FMS sample and an age- and gender-matched pain-free sample (N = 94); and (iii) if subgroups of participants with FMS are identifiable according to interoceptive accuracy levels. We found the PAT was tolerable in the FMS sample, with additional task breaks and a recommended hand posture. The FMS sample were more likely to be classified as 'interoceptive' on the PAT, and had significantly higher self-reported interoception compared to the pain-free sample. Within the FMS sample, we identified a subgroup who demonstrated very strong evidence of being interoceptive, and concurrently had lower fibromyalgia symptom impact (although the effect size was small). Conversely, self-reported interoception was positively correlated with FMS symptom severity and impact. Overall, interoception may be an important factor to consider in understanding and managing FMS symptoms. We recommend future longitudinal work to better understand associations between fluctuating FMS symptoms and interoception.

Are some interoceptive sensibility components more central than others? Using item pool visualisation to understand the psychometric representation of interoception.

Interoception refers to the processing of stimuli originating within the body and is widely considered a multidimensional construct. However, there remains a lack of consensus regarding the definition and measurement of the subjective, self-reported component, referred to here as interoceptive sensibility. As a contribution to knowledge on the topic, we sought to examine the construct commonality and distinguishability of seven self-report measures of interoceptive sensibility using Item Pool Visualisation (IPV), an illustrative method that locates item pools from within the same dataset and illustrates these in the form of nested radar charts. Adults from the United Kingdom (N = 802) completed seven measures of interoceptive sensibility, and the data were subjected to IPV. Results demonstrated that, of the included measures, the Multidimensional Assessment of Interoceptive Awareness-2 provided the closest and most precise measurement of the core interoceptive sensibility construct (i.e., core of the entire investigated item pool). The Body Awareness Questionnaire and the Private Body Consciousness Scale were also centrally located measures, while the Body Perception Questionnaire and the Body Responsiveness Scale appear to tap more distal aspects of the core construct. We discuss implications for interpreting complicated data patterns using measures of interoceptive sensibility and, more generally, for measuring the construct of interoceptive sensibility.

How is pain associated with pelvic mesh implants measured? Refinement of the construct and a scoping review of current assessment tools.

BACKGROUND: Recommendations for the management of pain related to pelvic mesh implants are still under development. One limitation that has impeded progress in this area is that mesh-related pain has not been consistently defined or measured. Here, we reviewed the ways in which pain associated with pelvic mesh implants has been measured, and mapped the ways in which these existing measures capture the construct. METHODS: First, we reviewed existing accounts of the pain associated with pelvic mesh implants to develop a multifaceted construct definition, which includes aspects related to pain intensity, timing, body location, phenomenological qualities, impact/interference with daily living, and patient expectations and beliefs. Next, we reviewed the ways that the construct has been measured in the extant literature. RESULTS: Within 333 eligible studies, 28 different assessments of pain associated with pelvic mesh were identified, and 61% of studies reported using more than one measurement tool. Questionnaire measures included measures designed to assess urological and/or pelvic symptoms, generic measures and unvalidated measures. We did not identify any validated questionnaire measures designed to assess pain associated with pelvic mesh implants. The phenomenological, location, and expectation/belief components of the construct were not captured well by the identified questionnaire measures, and there is no evidence that any of the identified measures have appropriate psychometric properties for the assessment of pain related to pelvic mesh implants. CONCLUSIONS: We recommend further qualitative research regarding women's experiences of pelvic mesh-related pain assessment, and the development of a condition-specific patient reported outcome measure.

Mindfulness, Interoception, and the Body.

In recent years, there has been a surge of interest in the topics of interoception and mindfulness from researchers, clinicians, and the general public alike (e [...].

Weaker implicit interoception is associated with more negative body image: Evidence from gastric-alpha phase amplitude coupling and the heartbeat evoked potential.

Interoception refers to the processing of internal bodily stimuli, while body image refers to appearance-related perceptions, affect, and cognitions. Previous research has found that body image is associated with self-reported and behavioural indices of interoception. Here, we extended this research by examining associations between measures of positive (i.e., body appreciation, functionality appreciation) and negative body image (i.e., body shame, weight preoccupation) and two electrophysiological indices of interoceptive processing, namely the heartbeat evoked potential (HEP) and gastric-alpha phase-amplitude coupling (PAC), in a sample of 36 adults. Significant negative associations were identified between the indices of negative body image and the interoception variables. Specifically, more negative HEP amplitude and lower gastric-alpha PAC were both associated with greater body shame and weight preoccupation. However, no significant associations were identified for the indices of positive body image. These findings extend previous work by demonstrating that there are significant associations between negative body image and previously unexplored components of cardiac and gastric interoception. This, in turn, could have important clinical applications, such as the HEP and gastric-alpha PAC both serving as biomarkers of negative body image.

Greater gastric interoception is associated with more positive body image: Evidence from adults in Malaysia and the United Kingdom.

Gastric interoception refers to the processing of sensory stimuli originating in the gut. Previous research has found that gastric interoception (measured using a water load task) is associated with drive for thinness in young Western women. However, associations with broader facets of body image and in diverse national groups have not been previously investigated. To address these issues, we asked samples of adults in the United Kingdom (UK; N = 91, women n = 54) and Malaysia (N = 100, women n = 50) to complete a 2-stage water load task (WLT) and measures of positive body image (i.e., body appreciation, functionality appreciation). The results indicated that a greater change in the intensity of self-reported WLT-related sensations was associated with significantly higher body appreciation and functionality appreciation after accounting for gender identity, body mass index, and national group. Behavioural performance on the WLT was significantly associated with body appreciation and functionality appreciation for the Malaysian sample, but not the UK adults, after accounting for gender identity and body mass index. These findings extend previous research by demonstrating that there are significant associations between facets of gastric interoception and previously unexplored facets of body image in both Western and non-Western settings.

Translation and validation of a Bahasa Malaysia (Malay) version of the Multidimensional Assessment of Interoceptive Awareness (MAIA).

OBJECTIVES: The 32-item Multidimensional Assessment of Interoceptive Awareness (MAIA) is a widely-used measure of multidimensional interoception. In the present study, we examined the psychometric properties of a Bahasa Malaysia (Malay) translation of the MAIA. METHODS: An online sample of 815 Malaysian Malays (women n = 403) completed a novel translation of the MAIA. Validated measures of trait mindfulness and self-esteem were also completed to facilitate a preliminary assessment of convergent validity. RESULTS: Exploratory factor analysis indicated that the MAIA items reduced to a 19-item, 3-factor model. The 3-factor model was further tested using confirmatory factor analysis (CFA) alongside the parent 8-factor model. Both models had good fit on some indices, but less-than-ideal fit on other indices. The 3-factor model evidenced comparatively better fit, with fit indices being adequate following modification. Multi-group CFA indicated both the 3-factor model and the 8-factor model had full strict invariance across sex. However, evidence for construct and convergent validity was mixed. CONCLUSIONS: Overall the 3-dimensional Malay MAIA was demonstrated to be both internally consistent and invariant across sex, but further evidence of construct and convergent validity is required. Issues that affect the dimensionality of MAIA scores in the present and extant work are discussed in conclusion.

Reduction of auditory input improves performance on the heartbeat tracking task, but does not necessarily enhance interoception.

Previous research utilising a between-subjects design has indicated that the use of noise-dampening ear protectors might enhance interoceptive accuracy (IAcc). In the present study, we further examined this effect using a repeated-measures, within-participants design, and investigated potential mechanisms that might explain the effect. 50 participants completed the heartbeat tracking task (HTT) with and without the use of industrial ear protectors, in a counter-balanced order. Participants were asked to count the number of heartbeats occurring in five discrete time intervals of 25, 35, 45, 55 and 95 s, without feeling for a manual pulse. HTT scores were significantly higher when ear protectors were worn, and the improvement in performance was greatest for participants with lower baseline IAcc. The ear protectors were associated with significantly increased self-reported heartbeat audibility, task-related confidence and concentration, and decreased levels of distractibility. Heartbeat audibility was also correlated with HTT performance when the ear protectors were worn. Because the use of industrial ear defenders resulted in increased heartbeat audibility, this manipulation should not be used to assess causal hypotheses related to changes in IAcc. However, it may serve as a simple, non-invasive manipulation to assess the effects of 'externalised' interoceptive signals.

An exploration of the associations between facets of interoceptive awareness and body image in adolescents.

Previous research suggests that lower interoceptive awareness is associated with more negative body image during adolescence. However, studies have not distinguished between adaptive and maladaptive modes of attention toward interoceptive signals, and relationships between interoceptive awareness and positive body image remain unexplored. To address these issues, a sample of 265 British adolescents (140 girls, 125 boys) aged 13-16 years completed measures of interoceptive awareness, body appreciation, functionality appreciation, body pride, body shame, and body surveillance. Correlational analyses broadly indicated that greater interoceptive awareness was significantly associated with more positive body image. Multiple regressions revealed significant predictive relationships between interoceptive awareness and all facets of body image in both girls and boys, except body surveillance, which was not statistically significant for girls. At the univariate level, the interoceptive awareness facets of Attention Regulation, Body Listening, Self-Regulation, and Trusting emerged as significant predictors for at least one facet of positive body image, whilst the Noticing and Emotional Awareness facets did not. These findings broadly align with previous research with adults, which has indicated that the way interoceptive stimuli are appraised and responded to might be more closely associated with facets of body image than the tendency to notice interoceptive stimuli.

Translation and validation of a Bahasa Malaysia (Malay) version of the Functionality Appreciation Scale.

The Functionality Appreciation Scale (FAS; Alleva et al., 2017) is a 7-item measure of an individual's appreciation of their body for what it can do and is capable of doing. To date, its psychometric properties have not been examined beyond the parent study and outside English-speaking samples. To rectify this, we examined the psychometric properties of a Bahasa Malaysia (Malay) translation of the FAS. An online sample of 815 Malaysia citizens completed a Malay translation of the FAS, along with validated measures of body appreciation, weight discrepancy, drive for muscularity, perceived pressure from and internalisation of appearance ideals, self-esteem, and trait mindfulness. Exploratory factor analyses supported a 1-dimensional factor structure of FAS scores, which was upheld using confirmatory factor analysis. FAS scores were also invariant across sex and there was no significant sex difference in scores. Construct validity was generally supported through significant associations with the additional measures included in the study. Incremental validity was also established insofar as functionality appreciation predicted self-esteem over-and-above the variance accounted for by other body image measures. The availability of the Malay FAS will be of use to scholars in Malaysia, but establishing cross-linguistic invariance will be an important next step.

Altered interoceptive processing in smokers: Evidence from the heartbeat tracking task.

Neuroimaging evidence suggests that interoceptive processing might be altered in nicotine addiction, however this has not yet been confirmed with behavioural measures. Therefore, we investigated the perception of internal bodily states in smokers (n = 49) and people who had never smoked (n = 51), by measuring interoceptive accuracy (IAcc) and interoceptive sensibility (IS). IAcc was measured with a heartbeat tracking task and a heartbeat discrimination task. Performance on the heartbeat tracking task may be influenced by one's ability to estimate an elapsed time interval so this was controlled by also administering a time-estimation (TE) task. IS was measured using two sub-scales from the Multidimensional Assessment of Interoceptive Awareness (MAIA). All smokers completed the Revised Fagerström Test for Nicotine Dependence (FTND-R) to measure addiction severity. Non-smokers performed significantly better than smokers on the heartbeat tracking task. There were no significant group differences observed for the remaining variables. Furthermore, none of the variables predicted addiction severity. This is the first demonstration of behavioural differences in interoception between smokers and non-smokers.

Multiple dimensions of interoceptive awareness are associated with facets of body image in British adults.

Previous research has identified a relationship between interoception and body image, where lower interoceptive awareness (IA) is associated with negative body image. However, relationships between facets of interoception and positive body image remain unexplored, and men and older adults remain underrepresented. To overcome these limitations, we assessed relationships between multiple dimensions of interoceptive awareness (IA) and multiple facets of body image in community adults. An online sample of 646 British adults (447 women) aged 18-76 years completed the Multidimensional Assessment of Interoceptive Awareness (MAIA), the Body Appreciation Scale-2, the Functionality Appreciation Scale, the Authentic Pride subscale from the Body and Appearance Self-Conscious Emotions Scale, and the Appearance Orientation and Overweight Preoccupation subscales from the Multidimensional Body-Self Relations Questionnaire. Hierarchical regressions revealed significant predictive relationships between IA and all five facets of body image after controlling for sex, body mass index, and age. In the final models, the MAIA subscales emerged as significant predictors for at least one facet of body image, with the exception of the MAIA Body Listening subscale. These findings extend previous work by demonstrating significant relationships between IA and previously unexplored facets of body image, which may hold promise for practitioner-based interventions.

The Feeling of Me Feeling for You: Interoception, Alexithymia and Empathy in Autism.

Following recent evidence for a link between interoception, emotion and empathy, we investigated relationships between these factors in autism spectrum disorder (ASD). 26 adults with ASD and 26 healthy participants completed tasks measuring interoception, alexithymia and empathy. ASD participants with alexithymia demonstrated lower cognitive and affective empathy than ASD participants without alexithymia. ASD participants showed reduced interoceptive sensitivity (IS), and also reduced interoceptive awareness (IA). IA was correlated with empathy and alexithymia, but IS was related to neither. Alexithymia fulfilled a mediating role between IA and empathy. Our findings are suggestive of an alexithymic subgroup in ASD, with distinct interoceptive processing abilities, and have implications for diagnosis and interventions.

The development of bodily self-consciousness: changing responses to the Full Body Illusion in childhood.

The present work investigates the development of bodily self-consciousness and its relation to multisensory bodily information, by measuring for the first time the development of responses to the full body illusion in childhood. We tested three age groups of children: 6- to 7-year-olds (n = 28); 8- to 9-year-olds (n = 21); 10- to 11-year-olds (n = 19), and a group of adults (n = 31). Each participant wore a head-mounted display (HMD) which displayed a view from a video camera positioned 2 metres behind their own back. Thus, they could view a virtual body from behind. We manipulated visuo-tactile synchrony by showing the participants a view of their virtual back being stroked with a stick at the same time and same place as their real back (synchronous condition), or at different times and places (asynchronous condition). After each period of stroking, we measured three aspects of bodily self-consciousness: drift in perceived self-location, self-identification with the virtual body, and touch referral to the virtual body. Results show that self-identification with the virtual body was significantly stronger in the synchronous condition than in the asynchronous condition even in the youngest group tested; however, the size of this effect increased with age. Touch referral to the virtual body was greater in the synchronous condition than in the asynchronous condition only for 10- to 11-year-olds and adults. Drift in perceived self-location was greater in the synchronous condition than in the asynchronous condition only for adults. Thus, the youngest age tested can self-identify with a virtual body, but the links between multisensory signals and bodily self-consciousness develop significantly across childhood. This suggests a long period of development of the bodily self and exciting potential for the use of virtual reality technologies with children.

People with higher interoceptive sensitivity are more altruistic, but improving interoception does not increase altruism.

People consistently show preferences and behaviors that benefit others at a cost to themselves, a phenomenon termed altruism. We investigated if perception of one's body signals - interoception - may be underlying such behaviors. We tested if participants' sensitivity to their own heartbeat predicted their decision on a choice between self-interest and altruism, and if improving this sensitivity through training would make participants more altruistic. Across these two experiments, interoceptive sensitivity predicted altruism measured through monetary generosity. Improving interoceptive sensitivity did, however, not lead to more altruistic behaviour. We conclude that there is a unique link between interoception and altruistic behaviour, likely established over an individual's history of altruistic acts, and the body responses they elicit. The findings suggest that humans might literally 'listen to their heart' to guide their altruistic behavior.

Visual capture and the experience of having two bodies - Evidence from two different virtual reality techniques.

In neurology and psychiatry the detailed study of illusory own body perceptions has suggested close links between bodily processing and self-consciousness. One such illusory own body perception is heautoscopy where patients have the sensation of being reduplicated and to exist at two or even more locations. In previous experiments, using a video head-mounted display, self-location and self-identification were manipulated by applying conflicting visuo-tactile information. Yet the experienced singularity of the self was not affected, i.e., participants did not experience having multiple bodies or selves. In two experiments presented in this paper, we investigated self-location and self-identification while participants saw two virtual bodies (video-generated in study 1 and 3D computer generated in study 2) that were stroked either synchronously or asynchronously with their own body. In both experiments, we report that self-identification with two virtual bodies was stronger during synchronous stroking. Furthermore, in the video generated setup with synchronous stroking participants reported a greater feeling of having multiple bodies than in the control conditions. In study 1, but not in study 2, we report that self-location - measured by anterior posterior drift - was significantly shifted towards the two bodies in the synchronous condition only. Self-identification with two bodies, the sensation of having multiple bodies, and the changes in self-location show that the experienced singularity of the self can be studied experimentally. We discuss our data with respect to ownership for supernumerary hands and heautoscopy. We finally compare the effects of the video and 3D computer generated head-mounted display technology and discuss the possible benefits of using either technology to induce changes in illusory self-identification with a virtual body.

Seeing the body modulates audiotactile integration.

Audiotactile integration has been studied using various experimental setups but so far crossmodal congruency effects (CCEs) have not been found for tactile targets paired with auditory distractors. In the present study we investigated whether audiotactile CCEs exist and, if so, whether these CCEs have similar characteristics to those found by previous authors with visual distractors. We measured audiotactile CCEs by attaching four vibrators to the backs of participants and presented auditory stimuli from four loudspeakers placed, in separate blocks, at different distances in front of or behind the participant's body. Participants discriminated the elevation of tactile stimuli while ignoring the auditory distractors. CCEs were found only when participants were provided with noninformative vision of their own body, as seen from behind via a camera and head-mounted display; they were absent when participants did not view their body. Furthermore, in contrast to visuotactile CCEs, audiotactile CCEs did not depend on whether the distractors were presented on the same or different side as the tactile targets. The present study provides the first demonstration of an audiotactile CCE: incongruent auditory distractors impaired performance on a tactile elevation discrimination task relative to performance with congruent distractors. We show that audiotactile CCEs differ from visuotactile CCEs as they do not appear to be as sensitive to the spatial relations between the distractors and the tactile stimuli. We also show that these CCEs are modulated by vision of the body.

Differential human brain activation by vertical and horizontal global visual textures.

Mid-level visual processes which integrate local orientation information for the detection of global structure can be investigated using global form stimuli of varying complexity. Several lines of evidence suggest that the identification of concentric and parallel organisations relies on different underlying neural substrates. The current study measured brain activation by concentric, horizontal parallel, and vertical parallel arrays of short line segments, compared to arrays of randomly oriented segments. Six subjects were scanned in a blocked design functional magnetic resonance imaging experiment. We compared percentage BOLD signal change during the concentric, horizontal and vertical blocks within early retinotopic areas, the fusiform face area and the lateral occipital complex. Unexpectedly, we found that vertical and horizontal parallel forms differentially activated visual cortical areas beyond V1, but in general, activations to concentric and parallel forms did not differ. Vertical patterns produced the highest percentage signal change overall and only area V3A showed a significant difference between concentric and parallel (horizontal) stimuli, with the former better activating this area. These data suggest that the difference in brain activation to vertical and horizontal forms arises at intermediate or global levels of visual representation since the differential activity was found in mid-level retinotopic areas V2 and V3 but not in V1. This may explain why earlier studies--using methods that emphasised responses to local orientation--did not discover this vertical-horizontal anisotropy.