Body ownership causes illusory self-attribution of speaking and influences subsequent real speaking

When we carry out an act, we typically attribute the action to ourselves, the sense of agency. Explanations for agency include conscious prior intention to act, followed by observation of the sensory consequences; brain activity that involves the feed-forward prediction of the consequences combined with rapid inverse motor prediction to fine-tune the action in real time; priming where there is, e.g., a prior command to perform the act; a cause (the intention to act) preceding the effect (the results of the action); and common-sense rules of attribution of physical causality satisfied. We describe an experiment where participants falsely attributed an act to themselves under conditions that apparently cannot be explained by these theories. A life-sized virtual body (VB) seen from the first-person perspective in 3D stereo, as if substituting the real body, was used to induce the illusion of ownership over the VB. Half of the 44 experimental participants experienced VB movements that were synchronous with their own movements (sync), and the other half asynchronous (async). The VB, seen in a mirror, spoke with corresponding lip movements, and for half of the participants this was accompanied by synchronous vibrotactile stimulation on the thyroid cartilage (Von) but this was not so for the other half. Participants experiencing sync misattributed the speaking to themselves and also shifted the fundamental frequency of their later utterances toward the stimulus voice. Von also contributed to these results. We show that these findings can be explained by current theories of agency, provided that the critical role of ownership over the VB is taken into account.There is growing evidence that the brain does not treat our body as relatively fixed, changing only slowly through time, but that its body representation demonstrates high plasticity. Although this is counter to common sense, a number of findings have shown that simple experimental manipulations can generate the illusion that an external object is part of our body (1, 2), that a plastic manikin (3, 4), and even a body displayed in immersive virtual reality (IVR), is our body (5–7). Furthermore, evidence suggests that such illusions have physiological and psychological consequences. For example, the rubber-hand illusion (RHI), where participants feel a somatic sense of ownership over a rubber hand through synchronous multisensory stimulation on the rubber and corresponding hidden real hand (1), has been shown to lead to a cooling of the real hand (8) as well as an increase in its histamine reactivity (9). The RHI over a black rubber hand can lead to a reduction of implicit racial bias in light-skinned people (10). When light-skinned people have a dark-skinned VB that apparently substitutes their own body, in IVR—as seen directly and in a virtual mirror, and that moves like themselves—they have the illusion that the body is theirs, which also results in a reduction of implicit racial bias (11). When average-sized adults have an illusion of body ownership over smaller or larger bodies, this results in changes in the perception of object sizes (12). Even more remarkably, the illusion of body ownership of adults over a virtual child body leads to overestimation of object sizes and changes in implicit attitudes about the self substantially beyond changes induced by the illusion of ownership of an adult shaped body of the same size as the child (13). Hence the type of body appears to carry with it physiological, perceptual, and even deep-seated attitudinal correlates.Following on from these findings the fundamental question in the present work is whether the factors that lead to a strong illusion of body ownership with respect to a VB would also lead to illusory agency over a specific action that was definitely not caused by participants, and where current explanations of agency apparently do not apply. “Agency” refers to the sensation of authorship of actions. Under normal circumstances humans are able to trivially distinguish their own motor actions from those of other people; we know when we are the cause of our own volitional motor actions and take responsibility for the effects. This sensation of agency has been the subject of significant study in recent years, and self-attribution of actions has been explained by a combination of feed-forward processing (we predict that we are to do an action and then observe the consequences of having carried it out) (14), with cause preceding effect, no other explanation for the result that is readily available (15), and a requirement for tight temporal binding between the intention to carry out the action and the resulting sensory consequences (16). Specific brain regions implicated in agency have been identified through the study of people with lesions (17), and although there is a significant intersection between brain activity in motor areas when observing someone else carrying out an action and when carrying it out ourselves, there are also additional processes that distinguish self-movement from others’ movement (18). Here we show that it is possible to generate an illusion of agency when apparently (i) there is no possibility of there having been feed-forward prediction, (ii) there is no thought or cause preceding the effect, and (iii) there is an obvious alternative explanation for the observed action.Our general hypothesis was that a strong illusion of ownership over a VB would map over to illusory agency with respect to an action—speaking —not executed by the participant, but only carried out by that VB. The voice that each participant heard had a higher fundamental frequency (FF) than his or her real voice. Our specific hypothesis was that a strong illusion of body ownership over the VB would result in the illusion of agency over the speaking. Moreover objective evidence of this effect would be the shift of FF of participants’ later utterances toward that of the heard voice.To study this we exploited an IVR system using a wide field-of-view (FOV) stereo head-tracked, head-mounted display (HMD) with headphones, and full-body motion-capture suit (Fig. 1A). Participants experienced a life-sized VB from a first-person perspective that was spatially coincident with and therefore substituted their own body. They saw the VB (or avatar) in a virtual mirror and when directly looking toward themselves (Fig. 1 B and C). During their experience, the VB uttered a set of prerecorded words. Our specific hypothesis was that the factors that would lead to a high level of body ownership would also result in the participants affirming that they had said the words, thus demonstrating illusory agency. Further evidence for such agency would be whether they would exhibit a shift in the FF of their voice toward that of the stimulus voice in their subsequent real utterances of the same words (19, 20).Open in a separate windowFig. 1.The experimental setup. The body of the participant was substituted by a sex-matched VB, viewed from 1PP, onto which body and head movements were mapped in real time for the sync condition. The body could also be seen as reflected in a virtual mirror. (A) Participants wore an HMD with earphones, a full-body motion-capture suit, and a vibrotactile device. (B) The female VB. (C) The male VB. B and C illustrate that the VB (here, the arms) could be seen directly when looking toward their own body, and also in the virtual mirror.We conducted the experiment with 44 participants using a between-groups design, with two binary factors referred to as visuomotor (async and sync) and vibrations (Voff and Von). In the sync condition the movements of the VB were synchronized in real time with the actual body movements of the participant. In the async condition the VB movements were generated from a prerecorded animation and independent of those of the participant. Based on past results we expected that the sync condition would result in a substantially greater illusion of body ownership over the VB than the async condition (11, 13, 21–23). The vibrations factor was designed to enhance the sense of speaking by applying vibratory feedback on the thyroid cartilage to coincide with the period that the embodied avatar was speaking (Von) or no vibratory feedback (Voff). The vibrations were synchronized with VB lip movements that were themselves synchronized with the word being said. Participants were sequentially allocated to one of the four cells of the factorial design in order of attendance to the experiment, with the final numbers as shown in Table S1, with approximate equal distribution of participants in the four cells of the experimental design and sex balance. Details are given in Materials and Methods and SI Materials and Methods and are shown in Movie S1.     

Psychologically induced cooling of a specific body part caused by the illusory ownership of an artificial counterpart

The sense of body ownership represents a fundamental aspect of our self-awareness, but is disrupted in many neurological, psychiatric, and psychological conditions that are also characterized by disruption of skin temperature regulation, sometimes in a single limb. We hypothesized that skin temperature in a specific limb could be disrupted by psychologically disrupting the sense of ownership of that limb. In six separate experiments, and by using an established protocol to induce the rubber hand illusion, we demonstrate that skin temperature of the real hand decreases when we take ownership of an artificial counterpart. The decrease in skin temperature is limb-specific: it does not occur in the unstimulated hand, nor in the ipsilateral foot. The effect is not evoked by tactile or visual input per se, nor by simultaneous tactile and visual input per se, nor by a shift in attention toward the experimental side or limb. In fact, taking ownership of an artificial hand slows tactile processing of information from the real hand, which is also observed in patients who demonstrate body disownership after stroke. These findings of psychologically induced limb-specific disruption of temperature regulation provide the first evidence that: taking ownership of an artificial body part has consequences for the real body part; that the awareness of our physical self and the physiological regulation of self are closely linked in a top-down manner; and that cognitive processes that disrupt the sense of body ownership may in turn disrupt temperature regulation in numerous states characterized by both.     

Removal of distal airway foreign body with the help of fluoroscopy in a child

Most foreign bodies are located in the central airways and can be reached and removed with either a flexible or rigid bronchoscope or a combination of the two methods. The removal of more distal foreign bodies can present a significant challenge. We describe a case of an 11‐year‐old child, who aspirated a sewing needle that lodged in a distal subsegment of the medial segment of the right lower lobe. As a result, it was visible only with the 2.8 mm flexible bronchoscope (FOB). Mono‐planar fluoroscopic guidance was useful for confirming the placement of the 2.8 mm bronchoscope and allowing for a biopsy forceps to grasp the needle and move it to a larger airway, where it could then be removed safely using a larger FOB. Removal of radiopaque foreign bodies in the distal airways is possible with the aid of fluoroscopy and a small bronchoscope. This report also highlights the risk of aspirating sharp objects when they are placed into the mouth, especially by children, and the dangers posed by sharp object foreign body aspiration.     

Evaluation of a body image prevention programme for adolescent boys

Most previous programmes to address body dissatisfaction and body change strategies have been designed for females, particularly adolescent girls. Programmes are also needed for adolescent boys due to high levels of body dissatisfaction and unhealthy behaviours in this population. The present study developed, implemented and evaluated a prevention programme for young adolescent boys designed to address body image concerns and body change strategies and improve psychological adjustment. One hundred and twenty‐one boys between the ages of 12 and 13 years participated, with 69 boys in the control group and 52 in the prevention programme. The programme focused on self‐esteem and accepting differences and was run over two sessions. The results indicated an increase in satisfaction with muscles, the attribute of greatest concern to boys. The programme was also successful in increasing self‐esteem and lowering levels of negative affect. Future programmes need to build on the findings of this study and develop strategies to improve the body image concerns and unhealthy body change strategies among adolescent boys before they become entrenched. Copyright © 2005 John Wiley & Sons, Ltd and Eating Disorders Association.     

Non-infectious interstitial alveolitis and foreign body pulmonary vasculitis in a child treated for acute lymphoblastic leukemia

We report a case of a 14-month-old girl who was treated for acute lymphoblastic leukemia but died from interstitial alveolitis associated with foreign body vasculitis. This respiratory complication arose 3 months after an allogenic bone marrow transplant. No infectious agents (bacteria, virus, or parasite) were isolated from bronchial or lung tissue samples. Respiratory complications after chemotherapy are reviewed as well as the potential origin of the intravascular foreign bodies. Pediatr. Pulmonol. 1997; 23:382–385. © 1997 Wiley-Liss, Inc.     

Association between changes in body composition and the increasing prevalence of fatty liver in Japanese men

Aim: Prevalence of fatty liver is increasing. In this study, to elucidate the factor that contributes most to recent increases in prevalence of fatty liver, we determined the independent predictors for the onset of fatty liver and compared these predictors between 2000 and 2005. Methods: Japanese persons, aged 30–74 years, who participated in regular health checks at Kagoshima Kouseiren Medical Health Care Center (10 336 persons in 2000 and 11 011 persons in 2005) were enrolled in the study. Diagnosis of fatty liver was performed by ultrasonography. Body fat percentage (BFP) was determined using a bipedal bioimpedance instrument. Results: The prevalence of fatty liver has increased between 2000 and 2005 in men (33.3 vs 38.5% in 2000 vs 2005, respectively, P < 0.0001), but not in women (21.3 vs 21.0%, P = 0.8101). Logistic regression analysis revealed that both body mass index (BMI) and BFP are independent predictors of fatty liver in both men and women. BMI did not change in either men (23.4 ± 2.9 vs 23.8 ± 3.0 kg/m², P = 0.0528) or women (22.8 ± 3.1 vs 22.8 ± 3.3 kg/m², P = 0.9862) during the survey period. In contrast, BFP increased in men (20.6 ± 4.7 vs 22.3 ± 5.0 kg/m², P = 0.0003), but not in women (27.4 ± 5.5 vs 28.4 ± 5.9 kg/m², P = 0.3993). There was no significant change in triglycerides and glucose levels. Conclusion: These results suggest that altered body composition, particularly increased BFP without an increase in BMI, has developed in men and is strongly associated with the increasing prevalence of fatty live amongst Japanese men.     

Psychometric Evaluation and Norms for the Multidimensional Assessment of Interoceptive Awareness (MAIA) in a Clinical Eating Disorders Sample

Altered interoceptive awareness (IA) has been implicated in the pathophysiology of eating disorders; however, few comprehensive self‐report measures of IA exist in eating disorders. The present study sought to validate the Multidimensional Assessment of Interoceptive Awareness (MAIA), originally developed to assess IA in individuals practicing mind–body therapies, in an eating disorder sample. Adult and adolescent patients (n = 376) completed assessments upon admission to a partial hospital programme. Analyses examined the factor structure of the MAIA, scale means, scale–scale correlations, internal consistency and construct validity. Analyses also examined associations between MAIA subscales and eating disorder symptoms. Results supported the original eight‐factor structure of the MAIA. Internal consistency was acceptable, and the scales converged with associated measures. Importantly, Not Distracting, Self‐regulation, Body Listening and Trusting were most strongly associated with eating disorder symptoms. Results support use of the MAIA among eating disorders and provide further support for the relevance of IA in eating disorders. Copyright © 2017 John Wiley & Sons, Ltd and Eating Disorders Association.     

Locus of control and self‐esteem as correlates of body dissatisfaction in Croatian university students

The main aim of this research is to explore the relationship between locus of control, self‐esteem and body dissatisfaction in the sample of university students, as well as the sex differences among the measures. The Body Shape Questionnaire (BSQ), Rosenberg Self‐Esteem Scale and the Externality Scale have been used on the sample of 534 female and 183 male university students. The results suggest that body dissatisfaction plays a more significant role in self‐esteem for girls than it does for boys. However, even the girls still have significantly lower BSQ results in comparison with female university students in the UK, and especially in the USA. Copyright © 2005 John Wiley & Sons, Ltd and Eating Disorders Association.     

Non-invasive monitoring of core body temperature rhythms over 72 h in 10 bedridden elderly patients with disorders of consciousness in a Japanese hospital: A pilot study

The purpose of this study was to elucidate the body core temperature rhythms of bedridden elderly patients with disorders of consciousness (DOC) in a Japanese hospital using a simple, non-invasive, deep-body thermometer. We measured body core temperature on the surface of abdomen in 10 bedridden elderly patients with DOC continuously over 72 h. A non-heated core body temperature thermometer was used. The cycle of the body core temperature rhythm was initially derived by using the least squares method. Then, based on that rhythm, the mean, amplitude, and times of day of the highest and lowest body temperatures during the optimum cycle were determined using the cosinor method. We found a 24-h cycle in seven of the 10 patients. One patient had a 6-h, one a 12-h, and one a 63-h cycle. The mean value of the cosine curve in the respective optimum cycles was 36.48 ± 0.34 °C, and the amplitude was 0.22 ± 0.09 °C. Of the seven subjects with 24-h cycles, the highest body temperature occurred between 12:58 and 14:44 h in four. In addition to 24-h cycles of core temperature rhythm, short cycles of 12 and 6-h and a long cycle of 63-h were seen. In order to understand the temperature rhythms of bedridden elderly patients with DOC, it is necessary to monitor their core body temperatures, ideally using a simple, non-invasive device. In the future, it will be important to investigate the relationship of the core temperature rhythm to nursing care and living environment.     

角膜异物合并感染愈后泪膜稳定性临床分析

目的观察角膜异物合并感染治愈并停用药物后患眼主观不适感和泪膜、眼表结构的改变。方法入选73例(146眼)确诊为角膜异物合并感染的患者,常规治疗自然病程内痊愈并停用药物后,排除其他影响泪膜稳定性的因素,分别于愈后0、10、30、60d复诊并行泪液分泌试验(ST)、角膜荧光素染色(FL)、泪膜破裂时间(BUT)测量。患眼为患病组,对侧健康眼为对照组。结果角膜异物感染治愈后83.6%(61例)患者有类似干眼症的眼部不适,愈后60d恢复正常(P>0.05)。患眼泪膜稳定性低于对照组,各观察指标恢复时间和恢复曲线有差别,ST结果在愈后60d时与对照组无明显差别(P>0.05),而FL分值和BUT结果恢复较快,愈后30d已达正常水平(P>0.05),虽然ST愈后30d较愈后初始时已经明显好转(P<0.05),但测量值却仍低于对照组(P<0.05)。结论角膜异物合并感染治愈后泪膜稳定性下降,对协助了解其恢复过程及指导后续处理具有重要的参考价值。     

Non-invasive monitoring of core body temperature rhythms over 72 h in 10 bedridden elderly patients with disorders of consciousness in a Japanese hospital: A pilot study

The purpose of this study was to elucidate the body core temperature rhythms of bedridden elderly patients with disorders of consciousness (DOC) in a Japanese hospital using a simple, non-invasive, deep-body thermometer. We measured body core temperature on the surface of abdomen in 10 bedridden elderly patients with DOC continuously over 72 h. A non-heated core body temperature thermometer was used. The cycle of the body core temperature rhythm was initially derived by using the least squares method. Then, based on that rhythm, the mean, amplitude, and times of day of the highest and lowest body temperatures during the optimum cycle were determined using the cosinor method. We found a 24-h cycle in seven of the 10 patients. One patient had a 6-h, one a 12-h, and one a 63-h cycle. The mean value of the cosine curve in the respective optimum cycles was 36.48 ± 0.34 °C, and the amplitude was 0.22 ± 0.09 °C. Of the seven subjects with 24-h cycles, the highest body temperature occurred between 12:58 and 14:44 h in four. In addition to 24-h cycles of core temperature rhythm, short cycles of 12 and 6-h and a long cycle of 63-h were seen. In order to understand the temperature rhythms of bedridden elderly patients with DOC, it is necessary to monitor their core body temperatures, ideally using a simple, non-invasive device. In the future, it will be important to investigate the relationship of the core temperature rhythm to nursing care and living environment.     

Experiences of pregnancy‐related body shape changes and of breast‐feeding in women with a history of eating disorders

In spite of the growing problems of eating disorders in society, no publications have reported the cumulative prevalence of eating disorders among childbearing women. The condition may constitute a risk during pregnancy and the childbirth period. This study examined the frequency of self‐reported eating disorder histories in women who had been delivered 3–7 months earlier as well as their experiences of body shape changes and breast feeding and the length of the breast‐feeding periods. Five hundred and sixteen women were invited to participate, of whom 454 responded to a questionnaire (88 per cent). A history of an eating disorder was reported by 11.5 per cent of the respondents, with a predominance of younger women. Significantly fewer women among those reporting an eating disorder breast‐fed their 3‐month‐old baby. However, no difference was seen regarding feelings related to the transformed body shape. Almost all women described such feelings as positive. Copyright © 2003 John Wiley & Sons, Ltd and Eating Disorders Association.     

Dietary supplementation of tetradecylthioacetic acid increases feed intake but reduces body weight gain and adipose depot sizes in rats fed on high-fat diets

Aim: The pan-peroxisome proliferator-activated receptor (PPAR) ligand and fatty acid analogue tetradecylthioacetic acid (TTA) may reduce plasma lipids and enhance hepatic lipid metabolism, as well as reduce adipose tissue sizes in rats fed on high-fat diets. This study further explores the effects of TTA on weight gain, feed intake and adipose tissue functions in rats that are fed a high-fat diet for 7 weeks.
Methods: The effects on feed intake and body weight during 7 weeks' dietary supplement with TTA (∼200 mg/kg bw) were studied in male Wistar rats fed on a lard-based diet containing ∼40% energy from fat. Adipose tissue mass, body composition and expression of relevant genes in fat depots and liver were measured at the end of the feeding.
Results: Despite higher feed intake during the final 2 weeks of the study, rats fed on TTA gained less body weight than lard-fed rats and had markedly decreased subcutaneous, epididymal, perirenal and mesenteric adipose depots. The effects of TTA feeding with reduced body weight gain and energy efficiency (weight gain/feed intake) started between day 10 and 13. Body contents of fat, protein and water were reduced after feeding lard plus TTA, with a stronger decrease in fat relative to protein. Plasma lipids, including Non-Esterified Fatty Acids (NEFA), were significantly reduced, whereas fatty acid β-oxidation in liver and heart was enhanced in lard plus TTA-fed rats. Hepatic UCP3 was expressed ectopically both at protein and mRNA level (>1900-fold), whereas Ucp1 mRNA was increased ∼30-fold in epididymal and ∼90-fold in mesenteric fat after lard plus TTA feeding.
Conclusion: Our data support the hypothesis that TTA feeding may increase hepatic fatty acid β-oxidation, and thereby reduce the size of adipose tissues. The functional importance of ectopic hepatic UCP3 is unknown, but might be associated with enhanced energy expenditure and thus the reduced feed efficiency.     

Bright liver,body composition and insulin resistance changes with nutritional intervention: a follow‐up study

Background: Nonalcoholic fatty liver disease (NAFLD) because of its association with obesity, diabetes and insulin resistance (IR), is the hepatic expression of metabolic syndrome. Exercise and nutritional intervention can improve and prevent these inter‐related conditions; the relationships between the degree of IR and ultrasound (US) morphological post‐interventional changes are not defined. Aims: The aim of our study was to assess the relationship, if any, in NAFLD patients, among IR, BMI and degree of bright liver, before and after 6 months of a moderately hypocaloric/balanced dietary/lifestyle treatment. Fifty outpatients with a clinical and US diagnosis of NAFLD were studied. Methods: Liver echogenicity [Bright Liver Score (BLS)] was scored on a four‐graded scale. IR was assessed by homoeostasis model‐insulin resistance (HOMA‐IR). Body composition was assessed by bioimpedance assessment and skinfold measurements. Results: A significant decrease of BLS was observed, with a concurrent decrease of body weight, body mass index (BMI) and HOMA‐IR. Bright liver decrease has a trend parallel to IR, much less steep than the trend of bright liver reduction against US liver dimensions, body weight and BMI decrease. HOMA‐IR is the only baseline variable that enters significantly in the multiple regression and, alone, explains 21.4% of variance in predicting bright liver degree. After dietary interventions, both HOMA‐IR and BMI are significantly involved in the multiple regression and explain, together, 42.3% of variance in predicting bright liver degree; variation in BLS can be predicted by variation of body weight and of US longitudinal measurement of the liver. Conclusions: Liver US BLS appears to be a useful tool, both alone and along with other US measurements and body weight changes, for the assessment of clinical‐metabolic amelioration in patients treated with dietetic interventions. The clinical‐diagnostic role, if any, of other assessed laboratory analyses, in the subset of NAFLD, does not appear to be definite.