Despite concerns regarding its validity, the two-alternative forced-choice heartbeat detection task (2AFC-HDT) is a frequently used measure of cardiac interoceptive accuracy. In this task, participants must decide whether a series of tones occur synchronously with their heartbeats. One series of tones is predefined by the researcher as synchronous with heartbeats, and one series is predefined as asynchronous. The 2AFC-HDT may result in individuals judged to be not interoceptive when they are, either if participants perceive their heartbeats as occurring synchronously with tones predefined as asynchronous rather than synchronous with their heartbeats, or if they do not perceive either set of tones as synchronous. Currently, there is little data on the proportion of participants this may affect. We addressed this using data from the Phase Adjustment Task (PAT) - a measure of cardiac interoceptive accuracy that determines if, and when in the cardiac cycle, a participant can perceive their heartbeat. The timing of heartbeat perception in 43 interoceptive participants was compared to the timing of synchronous and asynchronous tones used in the 2AFC-HDT, assuming temporal precision of 50, 100, and 150 ms. Results suggest that between 53.5%-97.7% of delay-based interoceptive individuals perceive heartbeats at a delay that does not correspond to the typical asynchronous or synchronous delays used to present tones on the 2AFC-HDT. These issues suggest that the 2AFC-HDT (or other measures that make assumptions about perceived timing of heartbeats) should not be used to measure cardiac interoceptive accuracy, or cardiac interoceptive insight (also known as awareness or metacognition).

Background: Fibromyalgia is a chronic condition characterised by widespread pain, as well as sleep disturbances, fatigue, and memory and concentration difficulties. Research suggests that an alteration in how the brain represents multisensory inputs from the body may cause or maintain chronic pain conditions, including fibromyalgia. Virtual reality (VR) setups that generate multisensory conflicts have been shown to alleviate pain, however, the optimal duration for such interventions remains unexplored. Here, we aimed to determine an optimal duration for the VR cardio-visual full body illusion (FBI) in fibromyalgia, considering both tolerability and changes in pain. Methods: Participants wore VR headsets to view a video of their own body, filmed from behind, and their self-image flashed in synchrony with their own heartbeat. We used an established dose-finding protocol to determine the ideal duration. Seven cohorts of participants (N = 20) were exposed to different durations of the FBI, with adjustments to duration made according to predefined criteria. Measures included a numeric rating scale for pain intensity, pressure pain thresholds, and scales measuring fibromyalgia symptom severity and impact. Results: We found a quadratic relationship between session duration and changes in self-reported pain-intensity, with 8–16-minute durations yielding the most significant improvements. Notably, in the 12-minute cohorts pain relief was sustained at 24-hour follow-up, and this is the recommended duration for future research. Conclusions: The present research represents a key step towards developing an effective non-pharmacological intervention for fibromyalgia. Future dose-optimisation research should explore the optimum number of VR sessions and spacing between sessions.

Our autobiographical memories reflect our personal experiences at specific times in our lives. All life events are experienced while we inhabit our body, raising the question of whether a representation of our bodily self is inherent in our memories. Here we explored this possibility by investigating if the retrieval of childhood autobiographical memories would be influenced by a body illusion that gives participants the experience of ownership for a ‘child version’ of their own face. 50 neurologically healthy adults were tested in an online enfacement illusion study. Feelings of ownership and agency for the face were greater during conditions with visuo-motor synchrony than asynchronous conditions. Critically, participants who enfaced (embodied) their child-like face recollected more childhood episodic memory details than those who enfaced their adult face. No effects on autobiographical semantic memory recollection were found. This finding indicates that there is an interaction between the bodily self and autobiographical memory, showing that temporary changes to the representation and experience of the bodily self impacts access to memory.

INTRODUCTION:Cognitive impairment is a commonly observed characteristic of people living with schizophrenia (PLWS). Adequate monitoring of intellectual decline and status in this population requires reliable estimates of premorbid IQ because objective IQ data predating schizophrenia onset are often unavailable. However, premorbid IQ estimation in PLWS is frequently complicated by confounding factors. The primary objective of this systematic review is to explore and compare extant approaches for estimating premorbid IQ in PLWS and, in doing so, identify factors that might inform the selection of the most reliable method for this clinical population. METHOD:A systematic literature search was conducted across PubMed, Web of Science Core Collection, EBSCOhost, SCOPUS, and The Cochrane Library electronic bibliographic databases. After deduplication, study selection was conducted in line with predefined inclusion and exclusion criteria. The quality assessment of studies was conducted using the Effective Public Health Practice Project (EPHPP) Quality Assessment Tool. RESULTS:43 articles involving 8,012 participants with schizophrenia spectrum disorders were included. Premorbid IQ estimation methods such as the National Adult Reading Test (NART), Wide Range Achievement Test (WRAT), Test of Premorbid Functioning (ToPF), Wechsler Test of Adult Reading (WTAR), Oklahoma Premorbid Intelligence Estimate (OPIE), demographic regression algorithms, and "hold" test approaches based on subtests from the Wechsler Adult Intelligence Scale (WAIS) were employed. Studies comparing these methods report inconsistent levels of agreement, with differences associated with factors such as schizophrenia chronicity, age of onset, and years of education. CONCLUSIONS:A range of measures are available for estimating premorbid IQ in people living with schizophrenia. However, their precision is limited by several factors identified in this review. We urge researchers and clinicians to recognize these limitations. We have created an evidence-based guide to support the selection of the most optimal estimation method for premorbid IQ in PLWS.

Underpinned by the neurodiversity paradigm, scholars are increasingly interested in relationships between positive autistic identity (i.e., feeling satisfaction and pride with being autistic) and states of flourishing (i.e., where numerous aspects of a person's life and well-being are good) in autistic people. However, possible mediational pathways between these constructs remain relatively under-researched. Here, we propose a conceptual model wherein positive autistic identity is associated with flourishing in autistic adults via positive body image. To test this model, we recruited an online sample of 384 autistic adults (189 women, 195 men; M = 34.66 years, SD = 10.77) from the United Kingdom. Participants were asked to complete measures of satisfaction with autistic identity, body appreciation, and flourishing, and provide their demographic information. Structural equation modelling showed that body appreciation mediated the association between satisfaction with autistic identity and flourishing. The mediational triangle remained significantly robust after controlling for participant demographics. Future research should consider promoting positive autistic identity as a means of developing more positive body image and capacities to flourish in autistic adults.

Fibromyalgia is a chronic condition characterised by widespread pain, as well as sleep disturbances, fatigue, and memory and concentration difficulties. Research suggests that an alteration in how the brain represents multisensory inputs from the body may cause or maintain chronic pain conditions, including fibromyalgia. Extended reality (XR) and virtual reality setups generating multisensory conflicts have been shown to alleviate pain, however, the optimal duration for such interventions remains unexplored. Here, we aimed to determine an optimal duration for the cardio-visual full body illusion (FBI) in fibromyalgia, considering both tolerability and changes in pain. Participants wore headsets to view a video of their own body, filmed from behind, and their virtual body flashed in synchrony with their heartbeat. We used an established dose-finding protocol to determine the ideal duration (balancing benefit and tolerability). Seven cohorts of participants (N = 20) were exposed to different durations of the FBI, with adjustments to duration made according to predefined criteria. Measures included a numeric rating scale for pain intensity, pressure pain thresholds, and scales measuring fibromyalgia symptom severity and impact. We found a quadratic relationship between session duration and changes in self-reported pain-intensity, with 8–16-min durations yielding the most significant improvements. Notably, in the 12-min cohorts pain relief was sustained at 24-h follow-up, and this is the recommended duration for future research. These findings represent a key step towards developing an effective non-pharmacological intervention for fibromyalgia. Future dose-optimisation research should explore the optimum number of sessions and spacing between sessions.

Emerging evidence points to unique conceptualisations of positive body image in autistic individuals. However, there are no existing measures of positive body image that have been developed or validated for use with autistic adults. To rectify this, we developed a revised version of the BAS-2 - the BAS-2A - and examined its factorial validity and psychometric properties in a sample of autistic adults from the United Kingdom. Based on the results of exploratory factor analysis and scale purification, we extracted a 12-item, unidimensional model of BAS-2A scores in a first split-subsample (n = 273). Confirmatory factor analysis supported the unidimensional model of BAS-2A scores in a second split-subsample (n = 277). BAS-2A scores presented adequate composite reliability, measurement invariance across gender identity, and patterns of construct validity. For both women and men, BAS-2A scores correlated positively with self-esteem, well-being, quality of life, and adaptive coping, and inversely with dietary restraint, weight/shape overvaluation, body dissatisfaction, and depression. Finally, BAS2A scores demonstrated incremental validity, predicting self-esteem over-and-above body dissatisfaction. However, temporal stability of the BAS-2A over three weeks was not supported. These results support the BAS-2A as a psychometrically robust measure of body appreciation for use in autistic adults from the United Kingdom.

Previous evidence suggests males and females differ with respect to interoception-the processing of internal bodily signals-with males typically outperforming females on tasks of interoceptive accuracy. However, interpretation of existing evidence in the cardiac domain is hindered by the limitations of existing tools. In this investigation, we pooled data from several samples to examine sex differences in cardiac interoceptive accuracy on the phase adjustment task, a new measure that overcomes several limitations of the existing tools. In a sample of 266 individuals, we observed that females outperformed males, indicative of better cardiac interoceptive accuracy, but had lower confidence than males. These results held after controlling for sex differences in demographic, physiological and engagement factors. Importantly, these results were specific to the measure of cardiac interoceptive accuracy. No sex differences were observed for individuals who completed the structurally identical screener task, although a similar pattern of results was observed in relation to confidence. These surprising data suggest the presence of a female advantage for cardiac interoceptive accuracy and potential differences in interoceptive awareness (metacognition). Possible reasons for mixed results in the literature, as well as implications for theory and future research, are discussed.

Interpersonal distance (IPD) refers to the distance naturally maintained during social interactions, while peripersonal space (PPS) refers to the immediate space surrounding the body, or the space within reaching distance. Previous research has preliminarily indicated that IPD is associated with body image disturbances. We sought to expand extant literature by exploring associations between aspects of positive and negative body image, IPD, and PPS. Seventy-five women from the United Kingdom aged 18-40 years completed measures of body appreciation, body image flexibility, body shame, body surveillance, and body dissatisfaction. IPD boundaries were estimated using a lab-based comfort-distance task, whereas PPS boundaries were estimated using an audio-tactile reaction-time task. Measures of body acceptance by others and fear of negative evaluation were completed as potential mediators. Overall, we identified positive associations between IPD, body surveillance, and fear of negative evaluation, with no statistically significant associations identified between the other indices. The association between active IPD and body surveillance was mediated by fear of negative evaluation, even after controlling for demographic factors. These findings suggest a nuanced relationship between IPD and body image-related factors, highlighting the role of social evaluation anxiety. Future investigations should use experimental designs to further understand these relationships and their implications.

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).

While scholars have investigated positive body image across diverse populations, extant theory largely excludes those with differing socio-cognitive experiences, such as autistic individuals. Using constructivist grounded theory, this study sought to develop a grounded theory of positive body image in autistic individuals. One-to-one interviews with photo-elicitation were conducted with 20 autistic adults (7 women, 8 men, 5 non-binary/agender; aged 18-53 years) from the United Kingdom. Through a process of open, axial, and focused coding, a grounded theory was developed around a core category of positive body image in autistic adults and was found to comprise six themes: body connection, body acceptance, appreciating body functionality and neurodivergent strengths, having a body-positive protective filter, taking care of the body, and body and appearance neutrality. Our findings suggest that some aspects of positive body image in autistic individuals are consistent with those found in neurotypical adults. However, positive body image in autistic individuals further encompasses both the sensory (i.e., how the body is felt) and aesthetic (i.e., how the body is seen) body. These findings may stimulate research aimed at improving positive body image in autistic populations.

Background: Previous research suggests that the processing of internal body sensations (interoception) affects how we experience pain. There is some evidence that people with fibromyalgia syndrome (FMS), which is 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. We used a task which overcomes problems with previous tasks – the Phase Adjustment Task (PAT) – to measure interoception in adults with FMS. Methods: 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 control sample (N = 94); and (iii) if subgroups of participants with FMS could be identified according to interoceptive accuracy levels. Results: After including additional task breaks and a recommended hand posture, we found that the PAT was tolerable in the FMS sample. Participants in the FMS sample were more likely to be classified as ‘interoceptive’ on the PAT, and had significantly higher self-reported interoception and interoceptive beliefs compared to participants in the pain-free sample. Within the FMS sample, participants who were classified as interoceptive on the PAT had significantly lower symptom impact than the unclassified participants. Conversely, self-reported interoception was positively correlated with FMS symptom severity and impact. Conclusions: The present findings suggest that interoception may be an important factor to consider in understanding and managing FMS symptoms, and that the PAT is a useful tool for assessing interoception in this population. We recommend future longitudinal work to better understand associations between fluctuating FMS symptoms and interoceptive processing.

Autobiographical memories are memories of previous experiences of one’s self, therefore it seems likely that autobiographical memories and self-representations interact in the brain. To test this in relation to the bodily self, we investigated whether the retrieval of childhood autobiographical memories would be facilitated by an illusion of ownership for a ‘child version’ of the participant’s own face. 50 neurologically healthy adults were tested in an online enfacement illusion study. Feelings of ownership and agency for the face were greater during conditions with visuo-motor synchrony than conditions with asynchrony. Critically, participants who viewed their child-like face recollected more childhood episodic memory details than those who viewed their adult face. No effects on autobiographical semantic memory recall were found. This finding indicates that there is an interaction between the bodily self and autobiographical memory. Our experimental paradigm could in future be adapted for its potential clinical application in memory disorders.

The body is intrinsic to our sense of self and as such, any theoretical account of the self should also include contributions of the body. This Collection incorporates a series of papers that demonstrate the inextricable relationship between body and self. The papers include studies of body illusions and studies of observed differences in bodily experience in participants with psychiatric and physical conditions. Papers in the Collection also address methodological issues, because measuring and manipulating the bodily self does not come without challenges; subjective experiences are difficult to capture empirically. Making progress on these methodological limitations is crucial to further develop experimental design and thus our understanding of self-body relations.

Flotation-Reduced Environmental Stimulation Therapy (REST) and mindfulness meditation (MM) are known to induce altered states of consciousness (ASC) and self-consciousness. In this study, we use a phenomenological and predictive processing (PP) framework to compare the interventions alongside the psychedelic experience. Ego-dissolution scores were greater than ego-inflation scores in both groups and Mystical Experience Questionnaire (MEQ30) scores lay between those elicited by low and high dose psilocybin. The weakening of perceived body boundaries was predictive of increased ego-dissolution and MEQ_Total score in the MM group only. Having an existing meditation practice was associated with increased ASC in the MM group. Past psychedelic use did not predict the degree of ASC, but ‘openness to experience’ did. Our findings suggest that a combination of validated measures and phenomenological analysis proves illuminating in describing the rich phenomenological space occasioned by MM and flotation-REST, and for exploring the relationship between different aspects of consciousness.

EDITORIAL article Front. Hum. Neurosci., 18 March 2022Sec. Cognitive Neuroscience https://doi.org/10.3389/fnhum.2022.875947

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.

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 [...].