scholarly journals Acquisition of Ownership Illusion with Self-Disownership in Neurological Patients

2020 ◽  
Vol 10 (3) ◽  
pp. 170
Author(s):  
Mariella Pazzaglia ◽  
Anna Maria Giannini ◽  
Francesca Federico

The multisensory regions in frontoparietal cortices play a crucial role in the sense of body and self. Disrupting this sense may lead to a feeling of disembodiment, or more generally, a sense of disownership. Experimentally, this altered consciousness disappears during illusory own-body perceptions, increasing the intensity of perceived ownership for an external virtual limb. In many clinical conditions, particularly in individuals with a discontinuous or absent sense of bodily awareness, the brain may effortlessly create a convincing feeling of body ownership over a surrogate body or body part. The immediate visual input dominates the current bodily state and induces rapid plastic adaptation that reconfigures the dynamics of bodily representation, allowing the brain to acquire an alternative sense of body and self. Investigating strategies to deconstruct the lack of a normal sense of bodily ownership, especially after a neurological injury, may aid the selection of appropriate clinical treatment.

2021 ◽  
pp. 194-209 ◽  
Author(s):  
Shu Imaizumi ◽  
Tomohisa Asai ◽  
Michiko Miyazaki

This chapter discusses how the self emerges in the brain through the body and bodily actions. In terms of minimal selfhood, self-representation has two aspects: sense of body ownership and sense of agency over action. In the rubber hand illusion paradigm, multisensory and sensorimotor signals induce illusory ownership over a fake hand. Studies in healthy adults suggest a cross-referenced relationship between body and action as a mechanism of the self-representation. Specifically, one’s own hand can spontaneously move towards the fake hand due to illusory ownership, suggesting a body-to-action relationship. In contrast, an object which is moving synchronously with one’s hand can entail a sense of body ownership as well as a sense of agency, suggesting an action-to-body relationship. The chapter also discusses developmental and clinical perspectives. Immature self-recognition and body part localization in children suggest a prerequisite of representations of the self and body. Although such representations can deteriorate due to damage to the body and brain, amputees can incorporate phantom limb and prosthesis into their body representation through visuo-motor rehabilitation, regaining senses of ownership and agency over these limbs once again. The chapter proposes generation-loss-regeneration dynamism in self-representation originating from the cross-referenced body and action.


Author(s):  
Riitta Salmelin ◽  
Jan Kujala ◽  
Mia Liljeström

When seeking to uncover the brain correlates of language processing, timing and location are of the essence. Magnetoencephalography (MEG) offers them both, with the highest sensitivity to cortical activity. MEG has shown its worth in revealing cortical dynamics of reading, speech perception, and speech production in adults and children, in unimpaired language processing as well as developmental and acquired language disorders. The MEG signals, once recorded, provide an extensive selection of measures for examination of neural processing. Like all other neuroimaging tools, MEG has its own strengths and limitations of which the user should be aware in order to make the best possible use of this powerful method and to generate meaningful and reliable scientific data. This chapter reviews MEG methodology and how MEG has been used to study the cortical dynamics of language.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Caleb Liang ◽  
Wen-Hsiang Lin ◽  
Tai-Yuan Chang ◽  
Chi-Hong Chen ◽  
Chen-Wei Wu ◽  
...  

AbstractBody ownership concerns what it is like to feel a body part or a full body as mine, and has become a prominent area of study. We propose that there is a closely related type of bodily self-consciousness largely neglected by researchers—experiential ownership. It refers to the sense that I am the one who is having a conscious experience. Are body ownership and experiential ownership actually the same phenomenon or are they genuinely different? In our experiments, the participant watched a rubber hand or someone else’s body from the first-person perspective and was touched either synchronously or asynchronously. The main findings: (1) The sense of body ownership was hindered in the asynchronous conditions of both the body-part and the full-body experiments. However, a strong sense of experiential ownership was observed in those conditions. (2) We found the opposite when the participants’ responses were measured after tactile stimulations had ceased for 5 s. In the synchronous conditions of another set of body-part and full-body experiments, only experiential ownership was blocked but not body ownership. These results demonstrate for the first time the double dissociation between body ownership and experiential ownership. Experiential ownership is indeed a distinct type of bodily self-consciousness.


2016 ◽  
Vol 22 (7) ◽  
pp. 503-509 ◽  
Author(s):  
Barbara Adamik ◽  
Jakub Smiechowicz ◽  
Andrzej Kübler

Endotoxin is considered a key signaling molecule in the pathogenesis of sepsis and septic shock. Anti-endotoxin therapies may result in the improvement of a patient’s clinical condition and lower mortality. The pressing clinical challenge is to identify patients for whom endotoxin elimination would be the most beneficial. An endotoxin activity assay (EAA) has been available for detection of endotoxins, allowing selection of patients at high risk of endotoxemia in intensive care units (ICUs). We studied a cohort of 172 consecutive patients who had septic shock on admission to the ICU. Endotoxin activity (EA) was measured with a rapid chemiluminescent EAA, regarded as point-of-care testing. Endotoxemia with a mean EA of 0.59 ± 0.14 EAU was present in 104 patients (60%) and absent in 68 patients (EA = 0.25 ± 0.11 EAU). The risk of endotoxemia increased with the presence of a Gram-negative infection [odds ratio (OR) 3.1, 95% confidence interval (CI) 1.6–5.9; P = 0.001] and bacteremia (OR 3.8, 95% CI 1.6–8.9; P = 0.02) but did not change with a diagnosis of peritonitis (OR 1.03, 95% CI 0.54–1.97; P = 0.90). These findings indicate that anti-endotoxin interventions should be tailored to individual patients based on both clinical conditions and measured endotoxin levels.


Author(s):  
Toshiki Kusano ◽  
Hiroki Kurashige ◽  
Isao Nambu ◽  
Yoshiya Moriguchi ◽  
Takashi Hanakawa ◽  
...  

AbstractSeveral functional magnetic resonance imaging (fMRI) studies have demonstrated that resting-state brain activity consists of multiple components, each corresponding to the spatial pattern of brain activity induced by performing a task. Especially in a movement task, such components have been shown to correspond to the brain activity pattern of the relevant anatomical region, meaning that the voxels of pattern that are cooperatively activated while using a body part (e.g., foot, hand, and tongue) also behave cooperatively in the resting state. However, it is unclear whether the components involved in resting-state brain activity correspond to those induced by the movement of discrete body parts. To address this issue, in the present study, we focused on wrist and finger movements in the hand, and a cross-decoding technique trained to discriminate between the multi-voxel patterns induced by wrist and finger movement was applied to the resting-state fMRI. We found that the multi-voxel pattern in resting-state brain activity corresponds to either wrist or finger movements in the motor-related areas of each hemisphere of the cerebrum and cerebellum. These results suggest that resting-state brain activity in the motor-related areas consists of the components corresponding to the elementary movements of individual body parts. Therefore, the resting-state brain activity possibly has a finer structure than considered previously.


2021 ◽  
Vol 10 (1) ◽  
pp. 139
Author(s):  
Marta Matamala-Gomez ◽  
Antonella Maselli ◽  
Clelia Malighetti ◽  
Olivia Realdon ◽  
Fabrizia Mantovani ◽  
...  

Over the last 20 years, virtual reality (VR) has been widely used to promote mental health in populations presenting different clinical conditions. Mental health does not refer only to the absence of psychiatric disorders but to the absence of a wide range of clinical conditions that influence people’s general and social well-being such as chronic pain, neurological disorders that lead to motor o perceptual impairments, psychological disorders that alter behaviour and social cognition, or physical conditions like eating disorders or present in amputees. It is known that an accurate perception of oneself and of the surrounding environment are both key elements to enjoy mental health and well-being, and that both can be distorted in patients suffering from the clinical conditions mentioned above. In the past few years, multiple studies have shown the effectiveness of VR to modulate such perceptual distortions of oneself and of the surrounding environment through virtual body ownership illusions. This narrative review aims to review clinical studies that have explored the manipulation of embodied virtual bodies in VR for improving mental health, and to discuss the current state of the art and the challenges for future research in the context of clinical care.


2018 ◽  
Vol 38 (05) ◽  
pp. 539-547 ◽  
Author(s):  
Neil Vaishnav ◽  
Winston Chiong

AbstractThe doctrine of informed consent sits at the intersection of law, ethics, and neuroscience, posing unique challenges for human subject research involving neurological patients. These challenges are compounded by the variegated nature of both neurological injury and the law governing research consent. This article provides a framework for investigators likely to encounter subjects with some degree of neurological impairment, whose capacity to consent requires scrupulous assessment prior to enrollment in research trials. We consider several researches and disease contexts—from emergency epilepsy research to long-term dementia research—and clarify the ethical and legal principles governing consent for participation in each. We additionally explore empirical research on consent capacity and survey several areas of emerging ethical import that will require the attention of investigators in decades to come.


2018 ◽  
Vol 15 (2) ◽  
pp. 176-181 ◽  
Author(s):  
S. V. Trufanov ◽  
A. A. Fedorov ◽  
V. R. Mamikonyan ◽  
L. Yu. Tekeeva ◽  
S. A. Malozhen ◽  
...  

Purpose: to develop the optimal (safe and effective) method of diamond burr polishing of Bowman’s membrane (DBPBM) for the possible use it in the treatment of the recurrent corneal erosion syndrome (RCES) in the experiment.Material and methods. DBPBM in different modifications of the  method and the mechanical deepithelization were performed in  experiment on 19 human cadaver eyes. We use system Ophtho-Burr  for DBPBM that includes a tip and ophthalmic burrs with diameter  1mm, 2.5 mm, 5 mm, varying the speed of rotation of burr. For 3  eyes — polishing with the application of burr with a diameter of 5  mm, the rotation frequency of 4000 rpm using 2 passes over the  surface of the cornea. For 3 eyes — burr with a diameter of 2.5 mm,  rotation frequency of 4000 rpm in 2 perpendicular passes. For 3 eyes — diameter burr 1 mm at speed of 8000 rpm in 2 perpendicular  passes. For 3 eyes — diameter burr 1 mm at speed 4000 rpm with 4  passes along the surface of the cornea. For 4 eyes — diameter was 1 mm at speed of 4000 rpm in 2 perpendicular passes. For 3 the eyes  was conducted mechanical deepithelization. Subsequent histopathological investigation of the cornea was  performed by method of semi-thin section, with polychrome staining.Results. The obtained results of histological studies of DBPBM in  different versions on cadaver cornea is allowed to choose the optimal variant of surgical intervention for use in clinical conditions. It  consisted in a selection of burr with a diameter of 1 mm, the rotation frequency of the 4000 rpm and 2 perpendicular passes with a  moderate compression of the cornea. The abovementioned technique of intervention allows removing completely the corneal epithelium  with a basal membrane and save uniform in thickness, fully  deepitelizationed Bowman’s membrane.Conclusion.Careful and accurate removal of dysplastic corneal epithelium in cases of the recurrent corneal erosion syndrome using  proposed method in clinical conditions should contribute to the  creation optimal environments for adequate reepithelization with  steady epithelial-stromal adhesion. The remaining nearly intact  Bowman’s membrane after procedure can prevent some postoperative complications such as haze and induced refractive disorders.


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