scholarly journals The contribution of stimulating multiple body parts simultaneously to the illusion of owning an entire artificial body

PLoS ONE ◽  
2021 ◽  
Vol 16 (1) ◽  
pp. e0233243
Author(s):  
Sophie H. O’Kane ◽  
H. Henrik Ehrsson
Keyword(s):  
Body Part ◽  
Whole Body ◽  
Multisensory Perception ◽  
Entire Body ◽  
Body Ownership ◽  
Body Parts ◽  
Body Sensation ◽  
Three Body ◽  
Mixed Modelling ◽  
Full Body

The full-body ownership illusion exploits multisensory perception to induce a feeling of ownership of an entire artificial body. Although previous research has shown that synchronous visuotactile stimulation of a single body part is sufficient for illusory ownership of the whole body, the effect of combining multisensory stimulation across multiple body parts remains unknown. Therefore, 48 healthy adults participated in a full-body ownership illusion with conditions involving synchronous (illusion) or asynchronous (control) visuotactile stimulation to one, two, or three body parts simultaneously (2×3 design). We used questionnaires to isolate illusory ownership of five specific body parts (left arm, right arm, trunk, left leg, right leg) from the full-body ownership experience and sought to test not only for increased ownership in synchronous versus asynchronous conditions but also for potentially varying degrees of full-body ownership illusion intensity related to the number of body parts stimulated. Illusory full-body ownership and all five body-part ownership ratings were significantly higher following synchronous stimulation than asynchronous stimulation (p-values < .01). Since non-stimulated body parts also received significantly increased ownership ratings following synchronous stimulation, the results are consistent with an illusion that engages the entire body. Furthermore, we noted that ownership ratings for right body parts (which were often but not always stimulated in this experiment) were significantly higher than ownership ratings for left body parts (which were never stimulated). Regarding the effect of stimulating multiple body parts simultaneously on explicit full-body ownership ratings, there was no evidence of a significant main effect of the number of stimulations (p = .850) or any significant interaction with stimulation synchronicity (p = .160), as assessed by linear mixed modelling. Instead, median ratings indicated a moderate affirmation (+1) of an illusory full-body sensation in all three synchronous conditions, a finding mirrored by comparable full-body illusion onset times. In sum, illusory full-body ownership appears to be an ‘all-or-nothing’ phenomenon and depends upon the synchronicity of visuotactile stimulation, irrespective of the number of stimulated body parts.

scholarly journals The contribution of stimulating multiple body parts simultaneously to the illusion of owning an entire artificial body

2020 ◽  
Author(s):  
Sophie H. O’Kane ◽  
H. Henrik Ehrsson
Keyword(s):  
Onset Time ◽  
Body Part ◽  
Whole Body ◽  
Multisensory Perception ◽  
Entire Body ◽  
Body Ownership ◽  
Body Parts ◽  
The Right ◽  
Three Body ◽  
Full Body

AbstractThe full-body ownership illusion exploits multisensory perception to induce a feeling of ownership for an entire artificial body. Whilst previous research has shown that the synchronous visuotactile stimulation of a single body part is sufficient for illusory ownership over the whole body, the effect of combining multisensory stimulation across multiple body parts remains unknown. Therefore, 48 healthy adults participated in conditions of a full-body ownership illusion involving synchronous or asynchronous visuotactile stimulation to one, two or three body parts simultaneously (2 x 3 design). We developed a novel questionnaire to isolate the sense of ownership of five specific body parts (left leg, right leg, left arm, right arm, and trunk) from the full-body ownership experience and sought not only to test for greater (part and whole) body ownership in synchronous versus asynchronous stimulation, but also, potentially varying degrees of illusion intensity related to the number of body parts stimulated. As expected, illusory full-body ownership and all five body-part ownership ratings were significantly higher following synchronous stimulation (all p values ≤.01). Since non-stimulated body parts also received significantly higher ownership ratings following synchronous stimulation, the results are consistent with an illusion engaging the entire body. We further noted that ownership ratings for the right body parts (often stimulated) were significantly higher than ownership ratings for the left body parts (never stimulated). Regarding explicit feelings of full-body ownership, subjective ratings were not significantly enhanced by increasing the number of synchronously stimulated body parts (synchronicity x number stimulated interaction; p.099). Instead, median ratings indicated a moderate affirmation (+1) of full-body illusory sensation for all three synchronous conditions; a finding mirrored by full-body illusion onset time. The results support the notion that feelings of full-body ownership are mediated by a generalisation from stimulated part(s)-to-whole, supported by processes related to multisensory body perception.

scholarly journals Experiential ownership and body ownership are different phenomena

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Caleb Liang ◽  
Wen-Hsiang Lin ◽  
Tai-Yuan Chang ◽  
Chi-Hong Chen ◽  
Chen-Wei Wu ◽  
...  
Keyword(s):  
Conscious Experience ◽  
Distinct Type ◽  
Body Part ◽  
The Body ◽  
Body Ownership ◽  
Rubber Hand ◽  
Person Perspective ◽  
The One ◽  
First Time ◽  
Full Body

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.

scholarly journals Joint Pedestrian and Body Part Detection via Semantic Relationship Learning

2019 ◽  
Vol 9 (4) ◽  
pp. 752 ◽  
Author(s):  
Junhua Gu ◽  
Chuanxin Lan ◽  
Wenbai Chen ◽  
Hu Han
Keyword(s):  
Pedestrian Detection ◽  
Body Part ◽  
Upper Body ◽  
Whole Body ◽  
Body Parts ◽  
Semantic Relationship ◽  
The Public ◽  
Novel Approach ◽  
In The Wild ◽  
Person Search

While remarkable progress has been made to pedestrian detection in recent years, robust pedestrian detection in the wild e.g., under surveillance scenarios with occlusions, remains a challenging problem. In this paper, we present a novel approach for joint pedestrian and body part detection via semantic relationship learning under unconstrained scenarios. Specifically, we propose a Body Part Indexed Feature (BPIF) representation to encode the semantic relationship between individual body parts (i.e., head, head-shoulder, upper body, and whole body) and highlight per body part features, providing robustness against partial occlusions to the whole body. We also propose an Adaptive Joint Non-Maximum Suppression (AJ-NMS) to replace the original NMS algorithm widely used in object detection, leading to higher precision and recall for detecting overlapped pedestrians. Experimental results on the public-domain CUHK-SYSU Person Search Dataset show that the proposed approach outperforms the state-of-the-art methods for joint pedestrian and body part detection in the wild.

scholarly journals Visual Body Part Representation in the Lateral Occipitotemporal Cortex in Children/Adolescents and Adults

2020 ◽  
Vol 1 (1) ◽  
Author(s):  
Yuko Okamoto ◽  
Ryo Kitada ◽  
Takanori Kochiyama ◽  
Hiroaki Naruse ◽  
Kai Makita ◽  
...  
Keyword(s):  
Univariate Analysis ◽  
Age Groups ◽  
Body Representation ◽  
Body Part ◽  
Autism Spectrum ◽  
Whole Body ◽  
Body Parts ◽  
Body Images ◽  
Adolescents And Adults ◽  
Occipitotemporal Cortex

Abstract The lateral occipitotemporal cortex (LOTC) that responds to human bodies and body parts has been implicated in social development and neurodevelopmental disorders like autism spectrum disorder (ASD). Neuroimaging studies using a representational similarity analysis (RSA) revealed that body representation in the LOTC of typically developing (TD) adults is categorized into 3 clusters: action effector body parts, noneffector body parts, and face parts. However, its organization of younger people (i.e., children and adolescents) and its association with individual traits remain unclear. In this functional MRI study, TD adults and children/adolescents observed photographs of hands, feet, arms, legs, chests, waists, upper/lower faces, the whole body, and chairs. The univariate analysis showed that fewer child/adolescent participants showed left LOTC activation in response to whole-body images (relative to those of chairs) than adult participants. Contrastingly, the RSA on both age groups revealed a comparable body representation with 3 clusters of body parts in the bilateral LOTC. Hence, this result indicates that, although response to whole-body images can differ, LOTC body part representations for children/ adolescents and adults are highly similar. Furthermore, sensory atypicality is associated with spatial LOTC organization, suggesting the importance of this region for understanding individual difference, which is frequently observed in ASD.

scholarly journals Moving in on human motor cortex. Characterizing the relationship between body parts with non-rigid population Response Fields

2020 ◽  
Author(s):  
Wouter Schellekens ◽  
Carlijn Bakker ◽  
Nick F. Ramsey ◽  
Natalia Petridou
Keyword(s):  
Ring Finger ◽  
Body Part ◽  
7 Tesla ◽  
Whole Body ◽  
Body Parts ◽  
Population Response ◽  
Human Motor Cortex ◽  
Neuronal Populations ◽  
Cortical Motor ◽  
The Relationship

AbstractFor cortical motor activity, the relationships between different body part representations is unknown. Through reciprocal body part relationships, functionality of cortical motor areas with respect to whole body motor control can be characterized. In the current study, we investigate the relationship between body part representations within individual neuronal populations in motor cortices, following a 7 Tesla fMRI 18-body-part motor experiment in combination with our newly developed non-rigid population Response Field (pRF) model and graph theory. The non-rigid pRF metrics reveal somatotopic structures in all included motor cortices covering frontal, parietal, medial and insular cortices and that neuronal populations in primary sensorimotor cortex respond to fewer body parts than secondary motor cortices. Reciprocal body part relationships are estimated in terms of uniqueness, clique-formation, and importance. We report unique response profiles for the knee, a clique of body parts surrounding the ring finger, and a central role for the shoulder and wrist. These results reveal associations among body parts from the perspective of the central nervous system, while being in agreement with intuitive notions of body part usage.

How do you smile along a path?

2019 ◽  
Vol 36 (3) ◽  
pp. 343-363 ◽  
Author(s):  
Patricia Irwin
Keyword(s):  
Syntactic Structure ◽  
Body Part ◽  
The Body ◽  
Whole Body ◽  
Body Parts ◽  
Syntactic Category ◽  
Root Structure ◽  
Core Component ◽  
Syntactic Structures ◽  
Root Content

Abstract This paper argues that a core component of root meaning is the distinction between body parts versus the body conceived as a whole. This distinction is shown to be relevant in the acceptability of motion sentences in English with whole-body roots like $\sqrt {\textsc{dance}} $ and body-part roots like $\sqrt {\textsc{smile}} $. In keeping with the assumption that roots lack syntactic category, I argue that verbal roots occur freely in syntactic structures but that some root-structure combinations are degraded (or unacceptable), and that this is due to an incompatibility between conceptual root content and interpreted syntactic structure.

scholarly journals Ownership of an artificial limb induced by electrical brain stimulation

2016 ◽  
Vol 114 (1) ◽  
pp. 166-171 ◽  
Author(s):  
Kelly L. Collins ◽  
Arvid Guterstam ◽  
Jeneva Cronin ◽  
Jared D. Olson ◽  
H. Henrik Ehrsson ◽  
...  
Keyword(s):  
Electrical Stimulation ◽  
Brain Stimulation ◽  
Human Subjects ◽  
Body Part ◽  
Multisensory Perception ◽  
Body Parts ◽  
Electrical Brain Stimulation ◽  
Artificial Limb ◽  
Somatosensory Stimulation ◽  
The Brain

Replacing the function of a missing or paralyzed limb with a prosthetic device that acts and feels like one’s own limb is a major goal in applied neuroscience. Recent studies in nonhuman primates have shown that motor control and sensory feedback can be achieved by connecting sensors in a robotic arm to electrodes implanted in the brain. However, it remains unknown whether electrical brain stimulation can be used to create a sense of ownership of an artificial limb. In this study on two human subjects, we show that ownership of an artificial hand can be induced via the electrical stimulation of the hand section of the somatosensory (SI) cortex in synchrony with touches applied to a rubber hand. Importantly, the illusion was not elicited when the electrical stimulation was delivered asynchronously or to a portion of the SI cortex representing a body part other than the hand, suggesting that multisensory integration according to basic spatial and temporal congruence rules is the underlying mechanism of the illusion. These findings show that the brain is capable of integrating “natural” visual input and direct cortical-somatosensory stimulation to create the multisensory perception that an artificial limb belongs to one’s own body. Thus, they serve as a proof of concept that electrical brain stimulation can be used to “bypass” the peripheral nervous system to induce multisensory illusions and ownership of artificial body parts, which has important implications for patients who lack peripheral sensory input due to spinal cord or nerve lesions.

scholarly journals A Hybrid Tracking System of Full-Body Motion Inside Crowds

Sensors ◽  
2021 ◽  
Vol 21 (6) ◽  
pp. 2108
Author(s):  
Maik Boltes ◽  
Juliane Adrian ◽  
Anna-Katharina Raytarowski
Keyword(s):  
Motion Tracking ◽  
Inertial Sensors ◽  
Tracking System ◽  
Body Motion ◽  
Whole Body ◽  
Body Parts ◽  
Movement Velocity ◽  
Camera System ◽  
Pedestrian Dynamics ◽  
Full Body

For our understanding of the dynamics inside crowds, reliable empirical data are needed, which could enable increases in safety and comfort for pedestrians and the design of models reflecting the real dynamics. A well-calibrated camera system can extract absolute head position with high accuracy. The inclusion of inertial sensors or even self-contained full-body motion capturing systems allows the relative tracking of invisible people or body parts or capturing the locomotion of the whole body even in dense crowds. The newly introduced hybrid system maps the trajectory of the top of the head coming from a full-body motion tracking system to the head trajectory of a camera system in global space. The fused data enable the analysis of possible correlations of all observables. In this paper we present an experiment of people passing though a bottleneck and show by example the influences of bottleneck width and motivation on the overall movement, velocity, stepping locomotion and rotation of the pelvis. The hybrid tracking system opens up new possibilities for analyzing pedestrian dynamics inside crowds, such as the space requirement while passing through a bottleneck. The system allows linking any body motion to characteristics describing the situation of a person inside a crowd, such as the density or movements of other participants nearby.

scholarly journals Prevalence of Musculoskeletal Disorders among Stone Polishing Workers using Stone Polishing Devices in Unorganized Sector of Guwahati (India)

2020 ◽  
Vol 9 (5) ◽  
pp. 140-142
Keyword(s):  
Whole Body ◽  
Sustained Load ◽  
Entire Body ◽  
Body Parts ◽  
Repetitive Motion ◽  
Long Duration ◽  
Guwahati City ◽  
Postural Load ◽  
Rapid Entire Body Assessment ◽  
Load Handling

Stone polishing is one of the prominent informal sector in India (and world as well), where a large number of stone polisher works for long duration. Stone polishing workers manually operate the polishing machine either in standing or sitting position to carry out polishing activities, and are quite prone to various MSDs (repetitive strain induced) and thereby injuries and accidents. The present research therefore intends to explore the occurrences of WMSDs among the stone-polishing workers, and with utmost attempt to put forward some recommendations regarding corrective measures. Thirty (30) male stone polishing workers were selected from the Guwahati city of Assam. A comprehensive study on discomfort feeling was carried out by the modified Nordic questionnaire which considered the information about work nature and job stress. Rapid Entire Body Assessment (REBA) method was followed to evaluate whole body postural load and risks associated with the job. The finding of the study contributes to the understanding of the working conditions of the stone polishing workers and their physical discomforts at various body parts (mainly the lower back, knees and shoulder) due to awkward posture, repetitive motion, force exertion and sustained load handling during polishing activities. To overcome the problem arisen from aforesaid ergonomic stressors associated with stone-polishing work, ergonomic design intervention pertaining to modification of the equipment / hand tool like handle design, easy manoeuvrability, avoiding hand-holding of weight etc. have been proposed

Action Recognition from Pose Signature in Static Image

2016 ◽  
Vol 30 (03) ◽  
pp. 1655010 ◽  
Author(s):  
Yinzhong Qian ◽  
Wenbin Chen ◽  
I-fan Shen
Keyword(s):  
Performance Improvement ◽  
Action Recognition ◽  
State Of The Art ◽  
Body Part ◽  
The Body ◽  
Whole Body ◽  
Body Parts ◽  
Static Image ◽  
Image Dataset ◽  
Part Structure

This paper addresses the problem of action recognition from body pose. Detecting body pose in static image faces great challenges because of pose variability. Our method is based on action-specific hierarchical poselet. We use hierarchical body parts each of which is represented by a set of poselets to demonstrate the pose variability of the body part. Pose signature of a body part is represented by a vector of detection responses of all poselets for the part. In order to suppress detection error and ambiguity we explore to use part-based model (PBM) as detection context. We propose a constrained optimization algorithm for detecting all poselets of each part in context of PBM, which recover neglected pose clue by global optimization. We use a PBM with hierarchical part structure, where body parts have varying granularity from whole body steadily decreasing to limb parts. From the structure we get models with different depth to study saliency of different body parts in action recognition. Pose signature of an action image is composed of pose signature of all the body parts in the PBM, which provides rich discriminate information for our task. We evaluate our algorithm on two datasets. Compared with counterpart methods, pose signature has obvious performance improvement on static image dataset. While using the model trained from static image dataset to label detected action person on video dataset, pose signature achieves state-of-the-art performance.

Sign in / Sign up

Export Citation Format

Share Document