The impact of weight and negative body image on the body schema in undergraduate women

BACKGROUND AND OBJECTIVES

Alterations of the sensory-motor body schema question the origins of such distortions. For example, in anorexia nervosa where patients think they are broader than they really are (body image) but act as if it was really the case (body schema). To date, the results of studies about what hinders the updating of the body schema so much (weight, body image) have been contradictory.

METHODS

We therefore conducted two studies that aimed to assess the impact of weight and body image problems on body schema in 92 young women without anorexia nervosa. For this purpose, we used a new body schema assessment tool (SKIN) that is sensitive enough to detect fine alterations of body schema in seven different body parts.

RESULTS

In Study 1, the thinness or overweight of the young women had a major impact on their tactile perception, especially because the assessed body part was a sensitive area for body dissatisfaction in young women (e.g., belly, thigh). In Study 2, the level of body dissatisfaction of the participants in its attitudinal and perceptual dimension also had a negative impact on their body schema, again in interaction with weight and body part.

CONCLUSIONS

These results imply that body dissatisfaction and thinness are predictors of massive body schema distortions. An oversized body schema could maintain various weight-control behaviors, thus risking the development, maintenance, or relapse of an eating disorder.

Forearm bisection task suggests an alteration in body schema in patients with functional movement disorders (motor conversion disorders)

OBJECTIVES

To explore potential alterations of the Body Schema, the implicit sensorimotor representation of one's own body, in patients with Functional Movement Disorders (FMD, Motor Conversion Disorders), characterized by neurological symptoms of altered voluntary motor function that cannot be explained by typical medical conditions. This investigation is prompted by the potential dissociation from their reportedly intact sense of ownership.

METHODS

10 FMD patients and 11 healthy controls (HC) underwent the Forearm Bisection Task, aimed at assessing perceived body metrics, which consists in asking the subject, blindfolded, to repeatedly point at the perceived middle point of their dominant forearm with the index finger of their contralateral hand, and a psychometric assessment for anxiety, depression, alexithymia, and tendency to dissociation.

RESULTS

FMD patients bisected their forearm more proximally (with an increased shift towards their elbow equal to 7.5%) with respect to HC; average bisection point was positively associated with anxiety levels in the whole sample, and with the tendency to dissociation in the FMD group.

CONCLUSIONS

FMD patients perceive their forearm as shorter than HC, suggesting an alteration of their Body Schema. The Body Schema can go through short- and long-term updates in the life course, mainly related to the use of each body segment; we speculate that, despite FMD being a disorder of functional nature, characterized by variability and fluctuations in symptomatology, the lack of sense of agency over a body part might be interpreted by the nervous system as disuse and hence influence the Body Schema, as deficits of organic etiology do.

Action does not drive visual biases in peri-tool space

Observers experience visual biases in the area around handheld tools. These biases may occur when active use leads an observer to incorporate a tool into the body schema. However, the visual salience of a handheld tool may instead create an attentional prioritization that is not reliant on body-based representations. We investigated these competing explanations of near-tool visual biases in two experiments during which participants performed a target detection task. Targets could appear near or far from a tool positioned next to a display. In Experiment 1, participants showed facilitation in detecting targets that appeared near a simple handheld rake tool regardless of whether they first used the rake to retrieve objects, but participants who only viewed the tool without holding it were no faster to detect targets appearing near the rake than targets that appeared on the opposite side of the display. In a second experiment, participants who held a novel magnetic tool again showed a near-tool bias even when they refrained from using the tool. Taken together, these results suggest active use is unnecessary, but visual salience is not sufficient, to introduce visual biases in peri-tool space.

Body ownership and kinaesthetic illusions: Dissociated bodily experiences for distinct levels of body consciousness?

Seeing an embodied humanoid avatar move its arms can induce in the observer the illusion that its own (static) arms are moving accordingly, the kinematic signals emanating from this avatar thus being considered like those from the biological body. Here, we investigated the causal relationship between these kinaesthetic illusions and the illusion of body ownership, manipulated through visuomotor synchronisation. The results of two experiments revealed that the sense of body ownership over an avatar seen from a first-person perspective was intimately linked to visuomotor synchrony. This was not the case for kinaesthetic illusions indicating that when superimposed on the biological body, the avatar is inevitably treated at the sensorimotor level as one's own body, whether consciously considered as such or not. The question of whether these two bodily experiences (body ownership and kinaesthetic illusion) are underpinned by distinct representations, the body image, and the body schema, is discussed.

Low frequency oscillations during hand laterality judgment task with and without personal perspectives: a preliminary study

Sense of personal perspective is crucial for understanding in attentional mechanisms of the perception in "self" or "other's" body. In a hand laterality judgment (HLJ) task, perception of perspective can be assessed by arranging angular orientations and depths of images. A total of 11 healthy, right-handed participants (8 females, mean age: 38.36 years, education: 14 years) were included in the study. The purpose of this study was to investigate behavioural and cortical responses in low-frequency cortical rhythms during a HLJ task. A total of 80-visual hand stimuli were presented through the experiment. Hand visuals were categorized in the way of side (right vs. left) and perspective (1st vs. 3rd personal perspective). Both behavioural outcomes and brain oscillatory characteristics (i.e., frequency and amplitude) of the Electroencephalography were analysed. All reaction time and incorrect answers for 3rd person perspective were higher than the ones for 1st person perspective. Location effect was statistically significant in event-related theta responses confirming the dominant activity of theta frequency in spatial memory tasks on parietal and occipital areas. In addition, we found there were increasing in delta power and phase in hand visuals with 1st person perspective and increasing theta phase in hand visuals with 3rd person perspective (p < 0.05). Accordingly, a clear dissociation in the perception of perspectives in low-frequency bands was revealed. These different cortical strategy in the perception of hand visual with and without perspectives may be interpreted as delta activity may be related in self-body perception, whereas theta activity may be related in allocentric perception.

Knowing your boundaries: no effect of tool-use on body representation following a gather-and-sort task

Internal representations of the body have received considerable attention in recent years, particularly in the context of tool-use. Results have supported the notion that these representations are plastic and tool-use engenders an extension of the internal representation of the arm. However, the limitations of the literature underlying this tool embodiment process have not been adequately considered or tested. For example, there is some evidence that tool-use effects do not extend beyond simplistic tool-use tasks. To further clarify this issue, 66 participants engaged in a period of tool-augmented reaches in a speeded gather-and-sort task. If task characteristics inherent to simplistic tasks are relevant to putative embodiment effects, it was predicted that there would be no effect of tool-use on tactile distance judgments or forearm bisections. A Bayesian analysis found considerable support for the null hypothesis in both outcome measures, suggesting that some of the evidence for tool embodiment may be based in task characteristics inherent in the narrow range of tool-use tasks used to study them, rather than a tool incorporation process. Potential sources of influence stemming from these characteristics are discussed.

Comparative effects of hypnotic suggestion and imagery instruction on bodily awareness

Bodily awareness is informed by both sensory data and prior knowledge. Although misleading sensory signals have been repeatedly shown to affect bodily awareness, only scant attention has been given to the influence of cognitive variables. Hypnotic suggestion has recently been shown to impact visuospatial and sensorimotor representations of body-part size although the mechanisms subserving this effect are yet to be identified. Mental imagery might play a causal or facilitative role in this effect, as it has been shown to influence body awareness in previous studies. Nonetheless, current views ascribe only an epiphenomenal role to imagery in the implementation of hypnotic suggestions. This study compared the effects of hypnotic suggestion and imagery instruction for influencing the visuospatial and sensorimotor aspects of body-size representation. Both experimental manipulations produced significant increases (elongation) in both representations compared to baseline, although the effects were larger in the hypnotic suggestion condition. The effects of both manipulations were highly correlated across participants, suggesting overlapping mechanisms. Self-reports suggested that the use of voluntary imagery did not significantly contribute to the efficacy of either manipulation. Rather, top-down effects on body representations seem to be partly driven by response expectancies, spontaneous imagery, and hypnotic suggestibility in both conditions. These results are in line with current theories of suggestion and raise fundamental questions regarding the mechanisms driving the influence of cognition on body representations.

Gait control by the frontal lobe

The frontal lobe is crucial and contributes to controlling truncal motion, postural responses, and maintaining equilibrium and locomotion. The rich repertoire of frontal gait disorders gives some indication of this complexity. For human walking, it is necessary to simultaneously achieve at least two tasks, such as maintaining a bipedal upright posture and locomotion. Particularly, postural control plays an extremely significant role in enabling the subject to maintain stable gait behaviors to adapt to the environment. To achieve these requirements, the frontal cortex (1) uses cognitive information from the parietal, temporal, and occipital cortices, (2) creates plans and programs of gait behaviors, and (3) acts on the brainstem and spinal cord, where the core posture-gait mechanisms exist. Moreover, the frontal cortex enables one to achieve a variety of gait patterns in response to environmental changes by switching gait patterns from automatic routine to intentionally controlled and learning the new paradigms of gait strategy via networks with the basal ganglia, cerebellum, and limbic structures. This chapter discusses the role of each area of the frontal cortex in behavioral control and attempts to explain how frontal lobe controls walking with special reference to postural control.

"The clothes (and the face) make the Starman": Facial and clothing features shape self-other matching processes between human observers and a cartoon character

Anthropomorphization occurs when human characteristics are attributed to nonhuman animals or objects. One process that could facilitate the anthropomorphization of nonhuman animals may be a self-other body-part matching mechanism wherein the body of the nonhuman animal is conceptually mapped to the human observer's representation of their body. The present study was designed to determine if specific features could facilitate body-part matching between the cartoon of a nonhuman animal and human observers. Participants responded to targets presented on the cartoon of a starfish. In No Structure conditions, dots and curved lines were distributed evenly within the starfish. In Face conditions, two dots and one curved line represented eyes and a mouth of a "face". In Clothes conditions, dots and lines represented a shirt and pants. Body-part matching emerged when the image had a face or clothing, but did not emerge in No Structure conditions. These studies provide unique evidence that the anthropomorphization of a nonhuman cartoon may be facilitated by human-like internal features on the image.

The bodily fundament of empathy: The role of action, nonaction-oriented, and interoceptive body representations

Mental representations with bodily contents or in various bodily formats have been suggested to play a pivotal role in social cognition, including empathy. However, there is a lack of systematic studies investigating, in the same sample of participants and using an individual differences approach, whether and to what extent the sensorimotor, perceptual, and interoceptive representations of the body could fulfill an explanatory role in the empathic abilities.To address this goal, we carried out two studies in which healthy adults were given measures of interoceptive sensibility (IS), action (aBR), and nonaction-oriented body representations (NaBR), and affective, cognitive, and motor empathy. A higher tendency to be self-focused on interoceptive signals predicted higher affective, cognitive, and motor empathy levels. A better performance in tasks probing aBR and NaBR predicted, respectively, higher motor and cognitive empathy levels.These findings support the view that the various facets of the empathic response are differently grounded in the body since they diversely involve representations with a different bodily format.Individual differences in the focus on one's internal body state representation can directly modulate all the components of the empathic experience. Instead, a body representation used interpersonally to represent both one's own body and others' bodies, in particular in its spatial specificity, could be necessary to accurately understand other people's minds (cognitive empathy), while a sensorimotor body representation used to represent both one's own body and others' bodies actions, could be fundamental for the self-awareness of feelings expressed in actions (motor empathy).

Neglect-like symptoms and their relationships with other clinical features in people with hand osteoarthritis: An exploratory study

BACKGROUND

Symptomatic hand osteoarthritis (OA) is a debilitating condition. Body schema impairments such as neglect-like symptoms have been previously reported in people with symptomatic hand OA, however, little is known about their clinical importance, or relationships with other clinical features.

OBJECTIVES

The aim of this cross-sectional study was to assess the prevalence of neglect-like symptoms in painful hand OA and their association with measures of depression, pain catastrophising, sleep quality, function, pain interference and pain duration whilst controlling for important covariates.

DESIGN

Secondary analysis of cross-sectional study.

METHODS

Logistic regression with age, sex, and worst pain intensity as covariates were utilised to assess differences between participants with and without neglect-like symptoms.

RESULTS

A total of 121 participants were recruited. Sixty-one percent of participants presented with neglect-like symptoms. Participants with longer pain duration had greater odds of presenting with neglect-like symptoms (OR: 1.10 95%CI: 1.01 to 1.19; p = 0.012). No difference was observed for depression, pain catastrophising, sleep quality, function, or pain interference.

CONCLUSIONS

A large proportion of participants with symptomatic hand OA reported neglect-like symptoms, the presence of which was associated with longer pain duration.

Dissociation between dreams and wakefulness: Insights from body and action representations of rare individuals with massive somatosensory deafferentation

The realism of body and actions in dreams is thought to be induced by simulations based on internal representations used during wakefulness. As somatosensory signals contribute to the updating of body and action representations, these are impaired when somatosensory signals are lacking. Here, we tested the hypothesis that individuals with somatosensory deafferentation have impaired body and actions in their dreams, as in wakefulness. We questioned three individuals with a severe, acquired sensory neuropathy on their dreams. While deafferented participants were impaired in daily life, they could dream of themselves as able-bodied, with some sensations (touch, proprioception) and actions (such as running or jumping) which had not been experienced in physical life since deafferentation. We speculate that simulation in dreams could be based on former, "healthy" body and action representations. Our findings are consistent with the idea that distinct body and action representations may be used during dreams and wakefulness.

What are the relevant categories, modalities, and outcome measures for assessing lower limb somatosensory function in children with upper motor neuron lesions? A Delphi study

PURPOSE

Somatosensory function of the lower limbs is rarely assessed in children with upper motor neuron lesions despite its potential relevance for motor function. We explored consensus regarding somatosensory categories (exteroception, proprioception, interoception, and body awareness), modalities, and outcome measures relevant to lower limb motor function.

METHODS

Fifteen international experts with experience of somatosensory function assessment participated in this Delphi study. Surveys of four rounds, conducted online, included questions on the relevance of somatosensory categories and modalities for motor function and on the use of potential outcome measures in clinical practice.

RESULTS

The experts reached consensus on the relevance of six modalities of the categories exteroception, proprioception, and body awareness. Based on their feedback, we formulated three core criteria for somatosensory outcome measures, namely suitability for clinical practice, child-friendliness, and relevance for motor function. None of the nine available outcome measures fulfilled each criterion. The experts also highlighted the importance of using and interpreting the tests in relation to the child's activity and participation.

CONCLUSION

There was expert consensus on three categories and six modalities of somatosensory function relevant for lower limb motor function. However, existing outcome measures will need to be adapted for use in paediatric clinical practice. IMPLICATION FOR REHABILITATIONConsensus was established for the categories and modalities of somatosensory function relevant for lower limb motor function of children with UMN lesion.Outcome measures should cover tactile function, joint movement and joint position and dynamic position sense, and spatial and structural body representation.None of the nine existing outcome measures fulfilled the core criteria: feasibility for clinical practice, child-friendliness, and relevance to motor function.

The impact of subclinical neck pain on goal-directed upper limb movement in the horizontal plane

Subclinical neck pain (SCNP) refers to recurrent neck pain and/or stiffness for which individuals have not yet sought treatment. Prior studies have shown that individuals with SCNP have altered cerebellar processing that exhibits an altered body schema. The cerebellum also plays a vital role in upper limb reaching movements through refining internal models and integrating sensorimotor information. However, the impact of SCNP on these processes has yet to be examined in the context of a rapid goal-directed aiming response that relies on feedforward and feedback processes to guide the limb to the target. To address this, SCNP and control participants performed goal-directed upper limb movements with the dominant and non-dominant hands using light and heavy styli in the horizontal plane. The results show greater peak accelerations in SCNP participants using the heavy stylus. However, there were no other group differences seen, possibly due to the fact that reaching behavior predominantly relies on vision such that any proprioceptive deficits seen in those with SCNP can be compensated. This study illustrates the robust compensatory nature of the CNS when performing end-effector reaching tasks, suggesting studies altering visual feedback may be needed to see the full impact of SCNP on upper limb aiming.

Are tools truly incorporated as an extension of the body representation?: Assessing the evidence for tool embodiment

The predominant view on human tool-use suggests that an action-oriented body representation, the body schema, is altered to fit the tool being wielded, a phenomenon termed tool embodiment. While observations of perceptual change after tool-use purport to support this hypothesis, several issues undermine their validity in this context, discussed at length in this critical review. The primary measures used as indicators of tool embodiment each face unique challenges to their construct validity. Further, the perceptual changes taken as indicating extension of the body representation only appear to account for a fraction of the tool's size in any given experiment, and do not demonstrate the covariance with tool length that the embodiment hypothesis would predict. The expression of tool embodiment also appears limited to a narrow range of tool-use tasks, as deviations from a simple reaching paradigm can mollify or eliminate embodiment effects altogether. The shortcomings identified here generate important avenues for future research. Until the source of the kinematic and perceptual effects that have substantiated tool embodiment is disambiguated, the hypothesis that the body representation changes to fit tools during tool-use should not be favored over other possibilities such as the formation of separable internal tool models, which seem to offer a more complete account of human tool-use behaviors. Indeed, studies of motor learning have observed analogous perceptual changes as aftereffects to adaptation despite the absence of handheld tool-use, offering a compelling alternative explanation, though more work is needed to confirm this possibility.

Do motor plans affect sensorimotor state estimates during temporal decision-making with crossed vs. uncrossed hands? Failure to replicate the dynamic crossed-hand effect

Hermosillo et al. (J Neurosci 31: 10019-10022, 2011) have suggested that action planning of hand movements impacts decisions about the temporal order judgments regarding vibrotactile stimulation of the hands. Specifically, these authors reported that the crossed-hand effect, a confusion about which hand is which when held in a crossed posture, gradually reverses some 320 ms before the arms begin to move from an uncrossed to a crossed posture or vice versa, such that the crossed-hand is reversed at the time of movement onset in anticipation of the movement's end position. However, to date, no other study has attempted to replicate this dynamic crossed-hand effect. Therefore, in the present study, we conducted four experiments to revisit the question whether preparing uncrossed-to-crossed or crossed-to-uncrossed movements affects the temporo-spatial perception of tactile stimulation of the hands. We used a temporal order judgement (TOJ) task at different time stages during action planning to test whether TOJs are more difficult with crossed than uncrossed hands ("static crossed-hand effect") and, crucially, whether planning to cross or uncross the hands shows the opposite pattern of difficulties ("dynamic crossed-hand effect"). As expected, our results confirmed the static crossed-hand effect. However, the dynamic crossed-hand effect could not be replicated. In addition, we observed that participants delayed their movements with late somatosensory stimulation from the TOJ task, even when the stimulations were meaningless, suggesting that the TOJ task resulted in cross-modal distractions. Whereas the current findings are not inconsistent with a contribution of motor signals to posture perception, they cast doubt on observations that motor signals impact state estimates well before movement onset.

Body Representation Alterations in Patients with Unilateral Brain Damage

OBJECTIVE

Systematic studies about the impact of unilateral brain damage on the different body representations (body schema, body structural representation, and body semantics) are still rare. Aim of this study was to evaluate body representation deficits in a relatively large sample of patients with unilateral brain damage and to investigate the impact of right or left brain damage on body representations (BRs), independently from deficits in other cognitive processes.

METHOD

Sixty-four patients with unilateral stroke (22 with left brain damage, LBD; 31 with right brain damage without neglect, RBD-N; 11 with right brain damage with neglect, RBD+N) and 41 healthy individuals underwent a specific battery including BR as well as control tasks.

RESULTS

In more than a third of the sample, selective (37.5%) and pure (31%) deficits of BR were presented and equally distributed among the different BRs (˜10% for each representation), with selective (27.2%) and pure (22.7%) body schema deficit mainly presented after left brain damage. As a group, patients with unilateral brain damage, independently of the side of lesion (LBD, RBD-N, RBD+N), had significantly worse performance on body structural representation with respect to healthy individuals, whereas LBD had numerically worse performance on body schema with respect to healthy individuals and RBD-N. No significant differences among groups were found on body semantics.

CONCLUSION

BR deficits are not a rare consequence of unilateral brain damage and are independent of a more general cognitive dysfunction. Accordingly, the need for an accurate assessment and specific neuropsychological training in clinical settings is discussed.

Effects of visual-motor illusion in stroke hemiplegic patients with left-side personal neglect: A report of two cases

Personal neglect is the neglect of self-body space, which often occurs in patients with unilateral spatial neglect (USN), but lacks a dedicated rehabilitation. The purpose of this study was to investigate the effects of visual-motor illusion (VMI) on two-stroke hemiplegic patients with left-side personal neglect. Case 1 was a 53-year-old man diagnosed with a right lenticulostriate artery infarction. Case 2 was a 76-year-old woman diagnosed with a right middle cerebral artery infarction. USN symptoms were not observed in either patient in the desk USN assessment, but personal neglect and USN symptoms in daily life were observed in both patients. Intervention effects were verified using an ABA design, comprising a 5-day three-phase (A1, B, A2). In phase B, VMI was performed on the paralyzed upper limb for 10 min in addition to conventional physical therapy. Outcomes measures were the Fluff test, Catherine Bergego Scale (CBS), Fugl-Meyer Assessment (FMA), and Functional Independence Measure (FIM). In both patients, no improvements were noted in FMA, but improvements were observed in the Fluff test, CBS, and FIM in phase B; these effects were retained in phase A2. Therefore, VMI may have contributed to improvements in Personal neglect and USN symptoms in daily life.

Body schema plasticity is altered in Developmental Coordination Disorder

Developmental Coordination Disorder (DCD) is a pathological condition characterized by impaired motor skills. Current theories advance that a deficit of the internal models is mainly responsible for DCD children's altered behavior. Yet, accurate movement execution requires not only correct movement planning, but also integration of sensory feedback into body representation for action (Body Schema) to update the state of the body. Here we advance and test the hypothesis that the plasticity of this body representation is altered in DCD. To probe Body Schema (BS) plasticity, we submitted a well-established tool-use paradigm to seventeen DCD children, required to reach for an object with their hand before and after tool use, and compared their movement kinematics to that of a control group of Typically Developing (TD) peers. We also asked both groups to provide explicit estimates of their arm length to probe plasticity of their Body Image (BI). Results revealed that DCD children explicitly judged their arm shorter after tool use, showing changes in their BI comparable to their TD peers. Unlike them, though, DCD did not update their implicit BS estimate: kinematics showed that tool use affected their peak amplitudes, but not their latencies. Remarkably, the kinematics of tool use showed that the motor control of the tool was comparable between groups, both improving with practice, confirming that motor learning abilities are preserved in DCD. This study thus brings evidence in favor of an alternative theoretical account of the DCD etiology. Our findings point to a deficit in the plasticity of the body representation used to plan and execute movements. Though not mutually exclusive, this widens the theoretical perspective under which DCD should be considered: DCD may not be limited to a problem affecting the internal models and their motor functions, but may concern the state of the effector they have to use.

Two-point discrimination and judgment of laterality in individuals with chronic unilateral non-traumatic shoulder pain

BACKGROUND

Cortical representation of the painful body region may be disrupted in several chronic pain conditions. The two-point discrimination test (TPDT) and the Left/Right Judgement Task (LRJT) have been used to identify changes in the cortical body schema in several chronic pain conditions. However, it is unclear if these changes are present for all chronic pain mechanisms.

OBJECTIVES

To investigate the integrity of the body schema of the painful shoulder in patients with chronic unilateral nociceptive shoulder pain.

METHODS

The sample consisted of 52 individuals with chronic unilateral nociceptive shoulder pain. The TPDT was measured over the anterosuperior and lateral regions of both shoulders using a staircase method. Participants also performed judgment tests of shoulder and foot laterality. The comparison of the TPDT and LRJT was performed using the linear regression model with mixed effects.

RESULTS

There was no difference in TPDT in the anterosuperior and lateral regions when comparing the symptomatic and asymptomatic shoulders. There was no difference in the LRJT accuracy and response time between the symptomatic and asymptomatic shoulders. No differences were observed when comparing LRJT variables from symptomatic shoulder and foot.

CONCLUSION

Therefore, results do not provide clear evidence of altered body schema in chronic nociceptive unilateral shoulder pain. This suggest that alterations in body representations may depend on the primary pain mechanism.

Phenomenological and existential contributions to the study of erectile dysfunction

The current medical approach to erectile dysfunction (ED) consists of physiological, psychological and social components. This paper proposes an additional framework for thinking about ED based on phenomenology, by focusing on the theory of sexual projection. This framework will be complementary to the current medical approach to ED. Our phenomenological analysis of ED provides philosophical depth and illuminates overlooked aspects in the study of ED. Mainly by appealing to Merleau-Ponty's Phenomenology of Perception, we suggest considering an additional etiology of ED in terms of a weakening of a function of sexual projection. We argue that sexual projection can be problematized through cognitive interferences, changes in the 'intentional arc', and modifications in the subject's 'body schema'. Our approach further highlights the importance of considering the 'existential situation' of patients with ED. We close by reflecting briefly on some of the implications of this phenomenological framework for diagnosis and treatment of ED.

Same action in different spatial locations induces selective modulation of body metric representation

Recent studies have hypothesized that the stereotypical representation of the body may reflect some functional aspects of routine actions that are performed in specific peripersonal domains. For example, the lower and upper limbs tend to 'act' in different peripersonal spaces and perform different functions. The present study aims to directly investigate the relationship between body representation and the spatial context where actions are performed. By means of a modified version of the body image task, we investigated body representation before and after a sorting task training in two groups of participants who were asked to carry out the same task/actions in two different spaces: on a table or on the floor, while sitting on a chair. Findings showed that a significant recalibration of the perceived upper arms' length occurred when participants were asked to perform a motor task on the floor. These results seem to suggest that the modulation of the body representation reflects an increase action capabilities driven by the contribution of motor training, and importantly, the location in which the action occurs. Furthermore, the modulation was not limited to the body part actively involved in the action (the arms), it extended to other upper body parts (the torso) to maintain, we propose, a functionally coherent representation of the upper body.

Body perception treatment, a possible way to treat body image disturbance in eating disorders: a case-control efficacy study

BACKGROUND

The body image disturbance (BID) is a common symptom in eating disorders, often observed and described in anorexia nervosa (AN) and bulimia nervosa (BN). Recently, this symptom has also been observed in binge eating disorder (BED). The research underlines that the BID presents three different altered components: affective, cognitive, and perceptual one. Current treatments for BID have mainly focused on the affective and cognitive components. Nowadays, the need emerges for treatments focused also on the perceptual component of the BID. In this paper, we present the results of an efficacy study on the body perception treatment (BPT), a new treatment for BID focused on the perceptual component of the disorder.

OBJECTIVE

We looked for an additional treatment effect on a protocol for ED inpatients to evaluate the efficacy of BPT. We performed the study through statistical analysis of admission and discharge scores.

METHODS

We conducted a case-control study in a hospital ward specialized in eating disorders. Two groups were identified: the control group (TAU; N = 91) and the experimental group (TAU + BPT; N = 91). The experimental group performed BTP activities in addition to the treatment at usual. All patients in both groups had an eating disorder diagnosis (AN, BN, BED and EDNOS/OSFED). Sampling occurred on a time basis and not by randomization. Moreover, all patients admitted in the ED hospital ward in the time frame considered (from end-2009 to mid-2017) were included in the study. BPT activities were introduced in mid-2013 and three psychometric instruments upon entry and discharge were used: Symptom Check List-90 (SCL-90) to measure the general psychopathological state; the Eating Disorder Inventory-3 (EDI-3) to estimate the incidence of personality traits strongly correlated to eating disorders; the body uneasiness test (BUT) to measure the body uneasiness. We performed a pre/post analysis for both groups; we studied the additional effect of the treatment through deltas analysis of the three questionnaires (Δ = assessment at discharge - assessment at the entrance). Data were analyzed using the Student T and the Wilcoxon rank-sum test.

RESULTS

The pre/post analysis showed statistically significant improvement in both conditions (TAU and TAU + BPT) in the general psychopathological state (SCL-90) and in the incidence of personality traits (EDI-3). Improvements in body uneasiness (BUT) were observed only in the experimental group (TAU + BPT). Furthermore, the analysis of the deltas shows more significant improvements in TAU + BPT compared to TAU in all the variables considered.

CONCLUSION

We found an additional effect of the BPT on TAU. The usual ED protocol added with BPT activities showed significantly better clinical results. We have interpreted these results in light of recent developments in the neuroscientific field of body image.

LEVEL OF EVIDENCE

Level II: controlled trial without randomization.

Talking with hands: body representation in British Sign Language users

Body representation (BR) refers to the mental representation of motor, sensory, emotional and semantic information about the physical body. This cognitive representation is used in our everyday life, continuously, even though most of the time we do not appreciate it consciously. In some cases, BR is vital to be able to communicate. A crucial feature of signed languages (SLs), for instance, is that body parts such as hands are used to communicate. Nevertheless, little is known about BR in SL: is the communicative function of the body overwriting the physical constraints? Here, we explored this question by comparing twelve British Sign Language (BSL) learners to seventeen tango dancers (body expertise but not for communication) and fourteen control subjects (no special body expertise). We administered the Body Esteem Scale (BES), the Hand Laterality Task (HLT) and the Mental Motor Chronometry (MMC). To control for visual imagery, we administered ad hoc control tasks. We did not identify parameters able to differentiate between SL users and the other groups, whereas the more implicit parameters distinguished clearly tango dancers from controls. Importantly, neither tasks on visual imagery nor the BES revealed differences. Our findings offer initial evidence that linguistic use of the body not necessarily influences the cognitive components we explored of body representation.

Vision is biased near handheld, but not remotely operated, tools

Previous studies have shown that after actively using a handheld tool for a period of time, participants show visual biases toward stimuli presented near the end of the tool. Research suggests this is driven by an incorporation of the tool into the observer's body schema, extending peripersonal space to surround the tool. This study aims to investigate whether the same visual biases might be seen near remotely operated tools. Participants used tools-a handheld rake (Experiment 1), a remote-controlled drone (Experiment 2), a remote-controlled excavator (Experiment 3), or a handheld excavator (Experiment 4)-to rake sand for several minutes, then performed a target-detection task in which they made speeded responses to targets appearing near and far from the tool. In Experiment 1, participants detected targets appearing near the rake significantly faster than targets appearing far from the rake, replicating previous findings. We failed to find strong evidence of improved target detection near remotely operated tools in Experiments 2 and 3, but found clear evidence of near-tool facilitation in Experiment 4 when participants physically picked up the excavator and used it as a handheld tool. These results suggest that observers may not incorporate remotely operated tools into the body schema in the same manner as handheld tools. We discuss potential mechanisms that may drive these differences in embodiment between handheld and remote-controlled tools.

Premature birth affects visual body representation and body schema in preterm children

Research has demonstrated that from the first six months of life infants show early sensitivity to body visual features and rely on sensorimotor and proprioceptive inputs in forming representations of their own bodies. Premature birth interferes with typical exposition to visual, sensorimotor and proprioceptive stimulation, thus presumably affecting the development of body representations. Here, we tested this hypothesis by comparing the performance of preterm children with that of age-matched full-termchildren in two tasks assessing, respectively, visual body processing and body schema. We found that preterm children had spared configural processing but altered holistic processing of others' bodies and showed a general difficulty in expressing visuospatial judgements on body stimuli. Furthermore, body-centered visuospatial abilities were associated with specific impairments in operating object-based visuospatial transformations. The findings of this study indicate that preterm birth might interfere with the development of body representations at the levels of body visual perceptual processing and of body schema, with effects even on visuo-spatial abilities for non-bodily stimuli. Body-centered rehabilitative interventions should be proposed to preterm children in order to enhance visuo-spatial abilities and higher-level cognitive functions.

Integrating mental imagery and fascial tissue: A conceptualization for research into movement and cognition

Mental imagery (MI) research has mainly focused to date on mechanisms of effect and performance gains associated with muscle and neural tissues. MI's potential to affect fascia has rarely been considered. This paper conceptualizes ways in which MI might mutually interact with fascial tissue to support performance and cognitive functions. Such ways acknowledge, among others, MI's positive effect on proprioception, body schema, and pain. Drawing on cellular, physiological, and functional similarities and associations between muscle and fascial tissues, we propose that MI has the potential to affect and be affected by fascial tissue. We suggest that fascia-targeted MI (fascial mental imagery; FMI) can therefore be a useful approach for scientific as well as clinical purposes. We use the example of fascial dynamic neuro-cognitive imagery (FDNI) as a codified FMI method available for scientific and therapeutic explorations into rehabilitation and prevention of fascia-related disabling conditions.

Body representations and cognitive ontology: Drawing the boundaries of the body image

The distinction between body image and body schema has been incredibly influential in cognitive neuroscience. Recently, researchers have begun to speculate about the relationship between these representations (Gadsby, 2017, 2018; Pitron & de Vignemont, 2017; Pitron et al., 2018). Within this emerging literature, Pitron et al. (2018) proposed that the long-term body image and long-term body schema co-construct one another, through a process of reciprocal interaction. In proposing this model, they make two assumptions: that the long-term body image incorporates the spatial characteristics of tools, and that it is distorted in the case of Alice in wonderland syndrome. Here, I challenge these assumptions, with a closer examination of what the term "long-term body image" refers to. In doing so, I draw out some important taxonomic principles for research into body representation.

Neural modifications in lower limb amputation: an fMRI study on action and non-action oriented body representations

The loss of sensorimotor and visual information that follows limb amputation is known to affect both the action-oriented (body schema, BS) and non-action oriented (NA) body representations. However, the neural underpinnings of these effects have not yet been fully understood. We investigated the neural correlates of body representations in a group of 9 healthy right-handed individuals with left lower limb amputation (LLA) and 11 healthy age-matched controls (HC) by using event-related functional magnetic resonance imaging. Participants were scanned while performing mental rotation of body parts (i.e. hand, foot and eye) and objects (i.e. a rear-view mirror). Although the performance of LLA were similar to that of HC, they showed a different activation profile in relation to both BS and to NA within a wide range of brain areas. The bilateral intraparietal sulcus was less activated in LLA than HC, whereas the bilateral anterior insula as well as the fusiform body area, the precentral gyrus, the supplementary motor area in the left hemisphere and the inferior occipital gyrus in the right hemisphere were more activated during the mental rotation of left stimuli in the LLA. Also, the left EBA showed higher activation during the mental rotation of the foot than that of the eye in the LLA but not in the HC. Our results are consistent with the hypothesis that left LLA yields to a modification in the body representation network even when it does not lead to clear behavioral deficits.

Visuo-tactile congruency influences the body schema during full body ownership illusion

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Visuo-tactile congruency influences the body schema, but not the body image.

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Movement behavior may provide a window into the unconscious body schema.

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We present novel methods to distort avatars and Euclidean space in virtual reality.

Previous research showed that full body ownership illusions in virtual reality (VR) can be robustly induced by providing congruent visual stimulation, and that congruent tactile experiences provide a dispensable extension to an already established phenomenon. Here we show that visuo-tactile congruency indeed does not add to already high measures for body ownership on explicit measures, but does modulate movement behavior when walking in the laboratory. Specifically, participants who took ownership over a more corpulent virtual body with intact visuo-tactile congruency increased safety distances towards the laboratory’s walls compared to participants who experienced the same illusion with deteriorated visuo-tactile congruency. This effect is in line with the body schema more readily adapting to a more corpulent body after receiving congruent tactile information. We conclude that the action-oriented, unconscious body schema relies more heavily on tactile information compared to more explicit aspects of body ownership.

Reliability and validity of a mobile tablet for assessing left/right judgements

BACKGROUND

Left/right judgement (LRJ) of body parts is commonly used to assess the ability to perform implicit motor imagery and the integrity of brain-grounded maps of the body. Clinically, LRJ are often undertaken using a mobile tablet, but the concurrent validity and reliability of this approach has not yet been established.

OBJECTIVES

To evaluate the concurrent validity and test-retest reliability of a mobile tablet for assessing LRJ.

METHOD

Participants completed LRJ for 50 hand images (Experiment 1), and 40 back, foot, or neck images (Experiment 2) using a mobile tablet and desktop computer in random order. Participants in Experiment 2 performed a repeat test the following day to assess test-retest reliability. Accuracy and response time (RT) were recorded.

RESULTS

Twenty participants aged 55.3 (±6.7) years in Experiment 1, and 37 participants aged 38.2 (±12.3) years in Experiment 2, were recruited. Concurrent validity of the mobile tablet was good to excellent for hand judgements (ICC_3,1 = 0.836 for RT; ICC = 0.909 for accuracy), and was good for back, foot, and neck judgements (ICC = 0.781 for accuracy; ICC = 0.880 for RT). Test-retest reliability of the mobile tablet was good to excellent (ICC = 0.824 for accuracy; ICC = 0.903 for RT).

CONCLUSIONS

The mobile tablet demonstrated good to excellent concurrent validity with the desktop computer in two separate samples. The mobile tablet also demonstrated good to excellent test-retest reliability. The mobile tablet for LRJ is a valid alternative to the original desktop version.

Development of affordance perception and recalibration in children and adults

Changes in the body over developmental time (e.g., physical growth) as well as over shorter timescales (e.g., wearing a backpack, carrying a large object) alter possibilities for motor action. How well can children recalibrate their perception of action possibilities to account for sudden changes to body size? The current study compared younger children (4-7 years), older children (8-11 years), and adults as they decided whether they could squeeze through doorways of varying widths. To test for age-related changes in recalibration to modified abilities versus perception of unmodified abilities, half of the participants wore a backpack while making judgments and squeezing through doorways and half did not. Results indicated that judgment accuracy improved with age but that participants had more difficulty when recalibrating to modified abilities. Bias in decision making also changed with age; whereas younger children made riskier decisions by attempting to fit through impossibly small doorways, older children were more cautious. Some particularly cautious participants never generated practice feedback by attempting (and failing) to fit through smaller doorways, which prevented them from recalibrating. Taken together with previous literature, the results of the current study suggest that the development of perception for unmodified versus modified ability proceeds at different rates and depends on the particular motor task.

"Will you draw me a pelvis?ˮ Dynamic neuro-cognitive imagery improves pelvic schema and graphic-metric representation in people with Parkinson's Disease: A randomized controlled trial

BACKGROUND

Body schema (i.e., the mental representations of the body), vital for motor and cognitive functions, is often distorted in people with Parkinson's disease (PD). Deficits in body, and especially pelvic, schema can further exacerbate motor and cognitive deficits associated with PD. Such deficits, including those in graphic and metric misjudgments, can manifest in drawing tasks. Mental imagery is a recommended approach for PD rehabilitation with potential for ameliorating body schema.

OBJECTIVE

To investigate the effect of a two-week dynamic neuro-cognitive imagery (DNI) training versus in-home learning and exercise control (learning/exercise) on pelvic schema and graphic representation (i.e., drawing height and width).

DESIGN

Twenty participants with idiopathic PD (Hoehn&Yahr I-III; M age: 65.75 ± 10.13) were randomly allocated into either a DNI or a learning/exercise group. Participants were asked to complete the "Draw Your Pelvisˮ test in which they drew their pelvis at pre- and post-intervention. Drawings were assessed for pelvic schema score and drawing dimensions (i.e., height and weight).

INTERVENTION

DNI anatomical and metaphorical imagery focusing on pelvic anatomy and biomechanics.

RESULTS

No difference (p > .05) was detected at baseline between drawn pelvis height and width. Following intervention, improvements were greater in the DNI group for pelvic schema (p < .01), drawn pelvic width (p < .05) and width-height difference (p < .05).

CONCLUSIONS

This study suggests that DNI could serve as a rehabilitation path for improving body schema in people with PD. Future studies should explore DNI mechanisms of effect and the effect of enhanced pelvic schema on motor and non-motor deficits in this population.

Distorted body image influences body schema in individuals with negative bodily attitudes

There is now a considerable body of evidence to suggest that internal representations of the body can be meaningfully separated into at least two general levels; body image as a perceptual construct and body schema as a motor metric. However, recent studies with eating disordered individuals have suggested that there may in fact be more interaction between these two representations than first thought. We aimed to investigate how body image might act to influence body schema within a typical, healthy population. 100 healthy adult women were asked to judge the smallest gap between a pair of sliding doors that they could just pass through. We then determined whether these estimates were sufficient to predict the size of the smallest gap that they could actually pass through, or whether perceptual and attitudinal body image information was required in order to make these predictions. It was found that perceptual body image did indeed mediate performance on the egocentric (but not allocentric) motor imagery affordance task, but only for those individuals with raised body image concerns and low self-esteem; body schema was influenced by both the perceptual and attitudinal components of body image in those with more negative bodily attitudes. Furthermore, disparities between perceived versus actual size were associated with body parts that had larger variations in adipose/muscle-dependent circumference. We therefore suggest that it may be the affective salience of a distorted body representation that mediates the degree to which it is incorporated into the current body state.

A new method for evaluating joint position sense using oral instructions based on body schema

[Purpose] This study investigated the efficacy of our independently developed method for measuring shoulder joint position sense using oral instructions based on body schema ("schema method") and investigated age-related changes. [Participants and Methods] Forty university students, 19 elderly individuals, and 16 elementary school students were included. Active shoulder abduction was measured in an upright sitting position. Target angles for position sense measurement were 45° of abduction (Target 45) and 90° of abduction (Target 90). The schema method consisted of indicating the target angles through oral instructions alone. The reproduction method and the imitation method were also used to measure angles. Abduction angle, absolute error, and variable error were calculated. [Results] A significant difference in abduction angle at Target 45 was observed between the schema method and the reproduction and imitation methods; no significant differences were observed at Target 90. No significant differences in variable error at Target 90 were observed among the three measurement methods. A significant difference in abduction angle was observed between university students and elderly individuals, and a significant difference in variable error was observed between elementary school students and elderly individuals. [Conclusion] Our body schema-based oral instruction method will be useful for evaluating joint position sense or proprioception.

How do the body schema and the body image interact?

Despite their differences, body schema and the body image representations are not only consistent in everyday life, but also sometimes consistent in pathological disorders, such as in Alice in Wonderland syndrome and anorexia nervosa. The challenge is to understand how they achieve such consistency. Recently, we suggested that these two representations were co-constructed (Pitron & Vignemont, 2017). In his reply, Gadsby (2018) invited us to clarify how this co-construction works and to what extent the body schema and the body image can reshape each other. Here we motivate conceptual grounds for a model on which these two forms of representation modify one another and explore theoretical options for the way(s) in which they might do so. In particular, we highlight the virtues of a serial model in which the body schema has some primacy over the body image, while also acknowledging the special role played by the body image.

Goal-Directed Reasoning and Cooperation in Robots in Shared Workspaces: an Internal Simulation Based Neural Framework

From social dining in households to product assembly in manufacturing lines, goal-directed reasoning and cooperation with other agents in shared workspaces is a ubiquitous aspect of our day-to-day activities. Critical for such behaviours is the ability to spontaneously anticipate what is doable by oneself as well as the interacting partner based on the evolving environmental context and thereby exploit such information to engage in goal-oriented action sequences. In the setting of an industrial task where two robots are jointly assembling objects in a shared workspace, we describe a bioinspired neural architecture for goal-directed action planning based on coupled interactions between multiple internal models, primarily of the robot's body and its peripersonal space. The internal models (of each robot's body and peripersonal space) are learnt jointly through a process of sensorimotor exploration and then employed in a range of anticipations related to the feasibility and consequence of potential actions of two industrial robots in the context of a joint goal. The ensuing behaviours are demonstrated in a real-world industrial scenario where two robots are assembling industrial fuse-boxes from multiple constituent objects (fuses, fuse-stands) scattered randomly in their workspace. In a spatially unstructured and temporally evolving assembly scenario, the robots employ reward-based dynamics to plan and anticipate which objects to act on at what time instances so as to successfully complete as many assemblies as possible. The existing spatial setting fundamentally necessitates planning collision-free trajectories and avoiding potential collisions between the robots. Furthermore, an interesting scenario where the assembly goal is not realizable by either of the robots individually but only realizable if they meaningfully cooperate is used to demonstrate the interplay between perception, simulation of multiple internal models and the resulting complementary goal-directed actions of both robots. Finally, the proposed neural framework is benchmarked against a typically engineered solution to evaluate its performance in the assembly task. The framework provides a computational outlook to the emerging results from neurosciences related to the learning and use of body schema and peripersonal space for embodied simulation of action and prediction. While experiments reported here engage the architecture in a complex planning task specifically, the internal model based framework is domain-agnostic facilitating portability to several other tasks and platforms.

Body representation does not lag behind in updating for the pubertal growth spurt

Both making perceptual judgments about your own body and successfully moving your body through the world depend on a mental representation of the body. However, there are indications that moving might be challenging when your body is changing. For instance, the pubertal growth spurt has been reported to be negatively correlated to motor competence. A possible explanation for this clumsiness would be that when the body is growing fast, updating the body representation may lag behind, resulting in a mismatch between internal body representation and actual body size. The current study investigated this hypothesis by testing participants ranging from aged 6 to 50 years on both a tactile body image task and a motor body schema task. Separate groups of participants, including those in the age range when pubertal growth spurt occurs, were asked to estimate the distance between two simultaneously applied tactile stimuli on the arm and to move their hand through apertures of different widths. Tactile distance estimations were equal between participants before, during, and after the age range where the pubertal growth spurt is expected. Similarly, Bayesian evaluation of informative hypotheses showed that participants in the age range of the growth spurt did not move through the apertures as if their representation of the hand was smaller than its physical size. These results suggest that body representations do not lag behind in updating for the pubertal growth spurt.

Distorted own-body representations in patients with dizziness and during caloric vestibular stimulation

There is increasing evidence that vestibular disorders evoke deficits reaching far beyond imbalance, oscillopsia and spatial cognition. Yet, how vestibular disorders affect own-body representations, in particular the perceived body shape and size, has been overlooked. Here, we explored vestibular contributions to own-body representations using two approaches. Study 1 measured the occurrence and severity of distorted own-body representations in 60 patients with dizziness and 60 healthy controls using six items from the Cambridge Depersonalization Scale. 12% of the patients have experienced distorted own-body representations (their hands or feet felt larger or smaller), 37% reported abnormal sense of agency, 35% reported disownership for the body, and 22% reported disembodiment. These proportions were larger in patients than controls. Study 2 aimed at testing whether artificial stimulation of the vestibular apparatus produced comparable distortions of own-body representations in healthy volunteers. We compared the effects of right-warm/left-cold caloric vestibular stimulation (CVS), left-warm/right-cold CVS and sham CVS on internal models of the left and right hands using a pointing task. The perceived length of the dorsum of the hand was increased specifically during left-warm/right-cold CVS, and this effect was found for both hands. Our studies show a vestibular contribution to own-body representations and should help understand the complex symptomatology of patients with dizziness.

Laterality recognition of images, motor performance, and aspects related to pain in participants with and without wrist/hand disorders: An observational cross-sectional study

OBJECTIVE

Musculoskeletal disorders are associated with altered sensory, proprioceptive and cognitive processes. Sensory processes affect the internal cortical representation of the body in space, the body schema, which in turn influences motor control. The purpose of this study was to determine if participants with wrist/hand disorders had impaired performance on a task associated with the body schema, the Left/Right Judgement Task (LRJT) and secondly how LRJT performance, motor performance, disability, pain and related aspects are associated.

METHODS

Fifteen healthy control participants and 15 participants with hand/wrist pain were asked to determine the laterality of images of hands. Measures of motor performance (Purdue Pegboard test), self-reported disability (Australian Canadian Hand Index), and pain related aspects (pain intensity, symptom duration, pain interference and affective distress) were recorded.

RESULTS

Participants with wrist/hand pain scored lower on all segments of the Purdue Pegboard test. There were differences in LRJT performance between groups for both Accuracy (p = 0.03) and Reaction Time (RT) (p < 0.01). There was no correlation between RT and Accuracy with pain intensity, pain duration, and disability. Both motor performance (r = 0.58-0.64) and LRJT performance Accuracy (r = 0.59) and RT (r = -0.56) were correlated with affective distress. A significant correlation was observed between RT and motor performance in healthy control participants (r = -0.56, p = 0.03) but not in participants with wrist/hand pain (r = -0.26, p = 0.44).

CONCLUSIONS

LRJT and motor performance was correlated with affective distress in participants with wrist/hand pain suggestive of complex interactions between cognitive-affective processes and sensorimotor integration.

How are the spatial characteristics of the body represented? A reply to Pitron & de Vignemont

In their article, Pitron and de Vignemont (2017) provide an insightful and well overdue discussion of the relationship between long-term body representation models and Alice in Wonderland syndrome. Here, I supplement their discussion with a number of observations. First, I present a cautionary note regarding the interpretation of experiential changes in body size as reflective of changes in the content of body representations. Second, I show how their evidence contradicts an alternative model of body representation arising from research into anorexia nervosa-the "LTB" hypothesis. Finally, I highlight a significant issue with their proposed co-construction model.

Fat or fiction? Effects of body size, eating pathology, and sex upon the body schema of an undergraduate population

Although there is a growing consensus that women with anorexia nervosa have a distorted body schema, the origins of this disturbance remain uncertain. The present investigation examined the effects of body size, eating pathology, and sex upon the body schema of an at-risk, undergraduate population. In Study 1, 98 participants mentally simulated their passage through apertures. When aperture width was manipulated, narrow and broad women over- and under-estimated their spatial requirements for passage, respectively. This relationship was exacerbated by dietary restraint. When aperture height was manipulated, short and tall men over- and under-estimated their spatial requirements for passage, respectively. Study 2 (N=32) replicated the association between women's veridical and internally-represented widths, although no significant effects of eating pathology were observed. Our findings suggest that body schema enlargement is not necessarily pathological, and may be driven by normal perceptual biases and internalised sociocultural body ideals.

Body-scaled action in obesity during locomotion: Insights on the nature and extent of body representation disturbances

OBJECTIVE

Conscious perception of our own body, also known as body image, can influence body-scaled actions. Certain conditions such as obesity are frequently accompanied by a negative body image, leaving open the question if body-scaled actions are distorted in these individuals.

METHODS

To shed light on this issue, we asked individuals affected by obesity to process dimensions of their own body in a real action: they walked in a straight-ahead direction, while avoiding collision with obstacles represented by door-like openings that varied in width.

RESULTS

Participants affected by obesity showed a body rotation behavior similar to that of the healthy weighted, but differences emerged in parameters such as step length and velocity.

CONCLUSION

When participants with obesity walk through door-like openings, their body parts rotation is scaled according to their physical body dimensions; however, they might try to minimize risk of collision. Our study is in line with the hypothesis that unconscious body-scaled actions are related to emotional, cognitive and perceptual components of a negative body image.

Optimized statistical parametric mapping procedure for NIRS data contaminated by motion artifacts : Neurometric analysis of body schema extension

This study investigated the spatial distribution of brain activity on body schema (BS) modification induced by natural body motion using two versions of a hand-tracing task. In Task 1, participants traced Japanese Hiragana characters using the right forefinger, requiring no BS expansion. In Task 2, participants performed the tracing task with a long stick, requiring BS expansion. Spatial distribution was analyzed using general linear model (GLM)-based statistical parametric mapping of near-infrared spectroscopy data contaminated with motion artifacts caused by the hand-tracing task. Three methods were utilized in series to counter the artifacts, and optimal conditions and modifications were investigated: a model-free method (Step 1), a convolution matrix method (Step 2), and a boxcar-function-based Gaussian convolution method (Step 3). The results revealed four methodological findings: (1) Deoxyhemoglobin was suitable for the GLM because both Akaike information criterion and the variance against the averaged hemodynamic response function were smaller than for other signals, (2) a high-pass filter with a cutoff frequency of .014 Hz was effective, (3) the hemodynamic response function computed from a Gaussian kernel function and its first- and second-derivative terms should be included in the GLM model, and (4) correction of non-autocorrelation and use of effective degrees of freedom were critical. Investigating z-maps computed according to these guidelines revealed that contiguous areas of BA7-BA40-BA21 in the right hemisphere became significantly activated ([Formula: see text], [Formula: see text], and [Formula: see text], respectively) during BS modification while performing the hand-tracing task.

Body representation in patients after vascular brain injuries

Neuropsychological literature suggests that body representation is a multidimensional concept consisting of various types of representations. Previous studies have demonstrated dissociations between three types of body representation specified by the kind of data and processes, i.e. body schema, body structural description, and body semantics. The aim of the study was to describe the state of body representation in patients after vascular brain injuries and to provide evidence for the different types of body representation. The question about correlations between body representation deficits and neuropsychological dysfunctions was also investigated. Fifty patients after strokes and 50 control individuals participated in the study. They were examined with tasks referring to dynamic representation of body parts positions, topological body map, and lexical and semantic knowledge about the body. Data analysis showed that vascular brain injuries result in deficits of body representation, which may co-occur with cognitive dysfunctions, but the latter are a possible risk factor for body representation deficits rather than sufficient or imperative requisites for them. The study suggests that types of body representation may be separated on the basis not only of their content, but also of their relation with self. Principal component analysis revealed three factors, which explained over 66% of results variance. The factors, which may be interpreted as types or dimensions of mental model of a body, represent different degrees of connection with self. The results indicate another possibility of body representation types classification, which should be verified in future research.

Effects of muscle dysmorphia, social comparisons and body schema priming on desire for social interaction: an experimental approach

Background

Muscle dysmorphia (MD) is a relatively young diagnosis referring to the desire for a high degree in lean muscle mass, while simultaneously believing that one is insufficiently muscular, mostly found in men. It goes along with a risk for social withdrawal to maintain rigid exercise and dietary regimen. The aim of the current study was thus, to explore differences in men with and without a risk for muscle dysmorphia regarding their desire for social interaction. Furthermore, we investigated potential effects of individual social comparison tendencies (the tendency to compare oneself with persons who are perceived to be superior or inferior to oneself on a certain dimension) and of one’s own body schema on the desire for social interaction.

Methods

One hundred physically active, college aged Austrian men were recruited via social media and flyers at fitness centers and the sports department of the University of Vienna. Participants were randomly assigned to a priming condition evoking their own body schema or a control condition and had to state their desire for social interaction with male or female stimulus persons of high or average attractiveness. We conducted a 2 (group of participant; men with vs. without a risk for MD) × 2 (priming condition; priming vs. non-priming) × 2 (attractiveness of stimulus person; highly attractive vs. less attractive) experimental design with different social comparison tendencies as covariates.

Results

Men with a risk for muscle dysmorphia showed lesser desire for social interaction than men without this risk, which can be seen as a risk factor for psychopathological outcomes. Generally, men with and without a risk for muscle dysmorphia did not differ with regard to their preferences for attractive stimulus persons as subjects for social interaction. We confirmed the notion that a tendency for downward social comparisons goes along with a diminished desire for social interaction.

Conclusions

This study showed that men with a risk for muscle dysmorphia appeared to be at higher risk for social withdrawal and that this is associated with social comparison tendencies. Future investigations on clinical populations are needed, for this population is highly prone to social isolation and negative outcomes related to it.

The effects of tool holding on body schema during motor imagery: a near-infrared spectroscopy study

[Purpose] The purpose of this study is to assess the influence of tool holding on brain activities during motor imagery in two tasks: imagining the movement of writing the alphabet while holding a pen and without holding the pen. [Subjects and Methods] Eleven healthy right-handed adults performed two tasks, holding a pen and not holding the pen during imagining the movement of writing the alphabet using a pen. Regions of targets were Brodmann areas 6 which were a motor-related region, 44/45 and 39/40 which taken on the role of forming the body schema. Change of the oxygenation state of hemoglobin associated with brain activity were acquired using a near-infrared spectroscopy. [Results] When using their dominant right hands, task-related increases in oxy-Hb were prominent in Brodmann areas 44/45 and 39/40 when imagining writing while actually holding the pen than when not. When using the non-dominant left hands, there were no significant differences between the two conditions in the same areas. [Conclusion] These results suggest that the tool held can be incorporated into the body schema in the motor imagery of an automated tool use task. Therefore, tool holding during motor imagery might be more effectively influence during rehabilitation.

Do adolescents with idiopathic scoliosis have body schema disorders? A cross-sectional study

BACKGROUND

To date etiology of adolescent idiopathic scoliosis appears complex and still remains unclear. A distorted body schema has been proposed to be a part of a sequence of pathological events in the development of adolescent idiopathic scoliosis.

OBJECTIVE

To investigate the awareness of trunk misalignment in adolescents with idiopathic scoliosis.

METHODS

Information about 44 adolescents with idiopathic scoliosis was collected as follows: age; sex; handedness; family history of scoliosis; back pain; sport practice; shoulder and waist line symmetry; leg length; dorsal kyphosis; back hump; rehabilitation; scoliotic curve; Risser sign. We evaluated awareness of trunk misalignment with a graphic table displaying pictures of progressively increasing scoliotic curves. Patients were asked to indicate which picture corresponded to their perceived own spinal alignment.

RESULTS

Patients with thoracolumbar scoliosis overestimated their actual thoracic spine curve. Patients with thoracic-thoracolumbar scoliosis underestimated their actual thoracolumbar spine curve and overestimated their actual lumbar spine curve. Scoliotic curve > 15°, double curve, younger age, back pain, family history of scoliosis and lower Risser score related with a misperception of trunk alignment.

CONCLUSIONS

Our results support the hypothesis that adolescents with idiopathic scoliosis have an altered corporeal awareness of their trunk alignment.

Combining manual therapy with pain neuroscience education in the treatment of chronic low back pain: A narrative review of the literature

Teaching people with chronic low back pain (CLBP) about the neurobiology and neurophysiology of their pain is referred to as pain neuroscience education (PNE). There is growing evidence that when PNE is provided to patients with chronic musculoskeletal pain, it can result in decreased pain, pain catastrophization, disability, and improved physical performance. Because the aim of PNE is to shift the patient's focus from the tissues in the low back as the source of their pain to the brain's interpretation of inputs, many clinicians could mistakenly believe that PNE should be a "hands-off," education-only approach. An argument can be made that by providing manual therapy or exercise to address local tissue pathology, the patient's focus could be brought back to the low back tissues as the source of their problem. In this narrative literature review, we present the case for a balanced approach that combines PNE with manual therapy and exercise by considering how manual therapy can also be incorporated for interventions with patients with CLBP. We propose that as well as producing local mechanical effects, providing manual therapy within a PNE context can be seen as meeting or perhaps enhancing patient expectations, and also refreshing or sharpening body schema maps within the brain. Ideally, all of this should lead to better outcomes in patients with CLBP.

Body representation in children with hemiplegic cerebral palsy

Clinical observations indicate that many children with hemiplegic cerebral palsy refrain from using or disregard the affected upper limb. The aim of the present study is to investigate deficits in different body representations (body schema, body structural description, and body image) in children with hemiplegic cerebral palsy (HCP) compared to typically-developing (TD) children. Three groups of children participated in this study: 42 TD children (aged 5.17-10.91 years), 23 children with right HCP (aged 5.83-10.92 years), and 22 children with left HCP (aged 5.67-10.90 years). The results demonstrate generalized deficits in all three body representations in children with HCP, and do not offer evidence for an effect of hemiplegia laterality.