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Kearney BE, Lanius RA. The brain-body disconnect: A somatic sensory basis for trauma-related disorders. Front Neurosci 2022; 16:1015749. [PMID: 36478879 PMCID: PMC9720153 DOI: 10.3389/fnins.2022.1015749] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2022] [Accepted: 10/14/2022] [Indexed: 08/16/2023] Open
Abstract
Although the manifestation of trauma in the body is a phenomenon well-endorsed by clinicians and traumatized individuals, the neurobiological underpinnings of this manifestation remain unclear. The notion of somatic sensory processing, which encompasses vestibular and somatosensory processing and relates to the sensory systems concerned with how the physical body exists in and relates to physical space, is introduced as a major contributor to overall regulatory, social-emotional, and self-referential functioning. From a phylogenetically and ontogenetically informed perspective, trauma-related symptomology is conceptualized to be grounded in brainstem-level somatic sensory processing dysfunction and its cascading influences on physiological arousal modulation, affect regulation, and higher-order capacities. Lastly, we introduce a novel hierarchical model bridging somatic sensory processes with limbic and neocortical mechanisms regulating an individual's emotional experience and sense of a relational, agentive self. This model provides a working framework for the neurobiologically informed assessment and treatment of trauma-related conditions from a somatic sensory processing perspective.
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Affiliation(s)
- Breanne E. Kearney
- Department of Neuroscience, Schulich School of Medicine and Dentistry, Western University, London, ON, Canada
| | - Ruth A. Lanius
- Department of Neuroscience, Schulich School of Medicine and Dentistry, Western University, London, ON, Canada
- Department of Psychiatry, Schulich School of Medicine and Dentistry, Western University, London, ON, Canada
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2
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Schettler A, Holstead I, Turri J, Barnett-Cowan M. Visual Self-Motion Feedback Affects the Sense of Self in Virtual Reality. Multisens Res 2020; 34:1-14. [PMID: 33535163 DOI: 10.1163/22134808-bja10043] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2019] [Accepted: 11/26/2020] [Indexed: 11/19/2022]
Abstract
We assessed how self-motion affects the visual representation of the self. We constructed a novel virtual-reality experiment that systematically varied an avatar's motion and also biological sex. Participants were presented with pairs of avatars that visually represented the participant ('self-avatar'), or another person ('opposite avatar'). Avatar motion either corresponded with the participant's motion, or was decoupled from the participant's motion. The results show that participants identified with (i) 'self-avatars' over 'opposite-avatars', (ii) avatars moving congruently with self-motion over incongruent motion, and importantly (iii) with the 'opposite avatar' over the 'self-avatar' when the opposite avatar's motion was congruent with self-motion. Our results suggest that both self-motion and biological sex are relevant to the body schema and body image and that congruent bottom-up visual feedback of self-motion is particularly important for the sense of self and capable of overriding top-down self-identification factors such as biological sex.
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Affiliation(s)
- Aubrieann Schettler
- 1Department of Philosophy, University of Waterloo, Waterloo, ON, Canada N2L 3G1
| | - Ian Holstead
- 2Department of Computer Engineering, University of Waterloo, Waterloo, ON, Canada N2L 3G1
| | - John Turri
- 1Department of Philosophy, University of Waterloo, Waterloo, ON, Canada N2L 3G1
- 3Cognitive Science Program, University of Waterloo, Waterloo, ON, Canada N2L 3G1
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Bretas RV, Taoka M, Suzuki H, Iriki A. Secondary somatosensory cortex of primates: beyond body maps, toward conscious self-in-the-world maps. Exp Brain Res 2020; 238:259-272. [PMID: 31960104 PMCID: PMC7007896 DOI: 10.1007/s00221-020-05727-9] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2019] [Accepted: 01/07/2020] [Indexed: 12/28/2022]
Abstract
Recent human imaging studies have revealed the involvement of the secondary somatosensory cortex (SII) in processes that require high-level information integration, such as self-consciousness, social relations, whole body representation, and metaphorical extrapolations. These functions are far beyond its known role in the formation of body maps (even in their most complex forms), requiring the integration of different information modalities in addition to somatosensory information. However, no evidence of such complex processing seems to have been detected at the neuronal level in animal experiments, which would constitute a major discrepancy between human and non-human animals. This article scrutinizes this gap, introducing experimental evidence of human and non-human primates’ SII functions set in context with their evolutionary significance and mechanisms, functionally situating the human SII as a primate brain. Based on the presented data, a new concept of a somatocentric holistic self is proposed, represented as a more comprehensive body-in-the-world map in the primate SII, taking into account evolutionary aspects that characterize the human SII and its implication in the emergence of self-consciousness. Finally, the idea of projection is introduced from the viewpoint of cognitive science, providing a logical explanation to bridge this gap between observed behavior and neurophysiological data.
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Affiliation(s)
- Rafael V Bretas
- Laboratory for Symbolic Cognitive Development, RIKEN Center for Biosystems Dynamics Research, Kobe, Japan
| | - Miki Taoka
- Laboratory for Symbolic Cognitive Development, RIKEN Center for Biosystems Dynamics Research, Kobe, Japan
| | - Hiroaki Suzuki
- Graduate School of Social Informatics, Aoyama Gakuin University, Tokyo, Japan
| | - Atsushi Iriki
- Laboratory for Symbolic Cognitive Development, RIKEN Center for Biosystems Dynamics Research, Kobe, Japan. .,Azrieli Program in Brain, Mind and Consciousness, Canadian Institute of Advanced Research, Toronto, Canada.
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Karnath HO, Kriechel I, Tesch J, Mohler BJ, Mölbert SC. Caloric vestibular stimulation has no effect on perceived body size. Sci Rep 2019; 9:11411. [PMID: 31388079 PMCID: PMC6684593 DOI: 10.1038/s41598-019-47897-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2019] [Accepted: 07/25/2019] [Indexed: 12/04/2022] Open
Abstract
It has been suggested that the vestibular system not only plays a role for our sense of balance and postural control but also might modulate higher-order body representations, such as the perceived shape and size of our body. Recent findings using virtual reality (VR) to realistically manipulate the length of whole extremities of first person biometric avatars under vestibular stimulation did not support this assumption. It has been discussed that these negative findings were due to the availability of visual feedback on the subjects' virtual arms and legs. The present study tested this hypothesis by excluding the latter information. A newly recruited group of healthy subjects had to adjust the position of blocks in 3D space of a VR scenario such that they had the feeling that they could just touch them with their left/right hand/heel. Caloric vestibular stimulation did not alter perceived size of own extremities. Findings suggest that vestibular signals do not serve to scale the internal representation of (large parts of) our body's metric properties. This is in obvious contrast to the egocentric representation of our body midline which allows us to perceive and adjust the position of our body with respect to the surroundings. These two qualia appear to belong to different systems of body representation in humans.
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Affiliation(s)
- Hans-Otto Karnath
- Centre of Neurology, Division of Neuropsychology, Hertie-Institute for Clinical Brain Research, University of Tübingen, Tübingen, Germany.
- Department of Psychology, University of South Carolina, Columbia, SC, 29208, USA.
| | - Isabel Kriechel
- Centre of Neurology, Division of Neuropsychology, Hertie-Institute for Clinical Brain Research, University of Tübingen, Tübingen, Germany
| | - Joachim Tesch
- Max Planck Institute for Biological Cybernetics, Tübingen, Germany
| | - Betty J Mohler
- Max Planck Institute for Biological Cybernetics, Tübingen, Germany
- Technical University Darmstadt, Institute of Sports Science, Darmstadt, Germany
| | - Simone Claire Mölbert
- Centre of Neurology, Division of Neuropsychology, Hertie-Institute for Clinical Brain Research, University of Tübingen, Tübingen, Germany
- Max Planck Institute for Biological Cybernetics, Tübingen, Germany
- Medical University Hospital Tübingen, Dept. of Psychosomatic Medicine and Psychotherapy, University of Tübingen, Tübingen, Germany
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Gallagher M, Dowsett R, Ferrè ER. Vection in virtual reality modulates vestibular-evoked myogenic potentials. Eur J Neurosci 2019; 50:3557-3565. [PMID: 31233640 DOI: 10.1111/ejn.14499] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2018] [Revised: 06/05/2019] [Accepted: 06/17/2019] [Indexed: 11/28/2022]
Abstract
The popularity of virtual reality (VR) has increased rapidly in recent years. While significant technological advancements are apparent, a troublesome problem with VR is that between 20% and 80% of users will experience unpleasant side effects such as nausea, disorientation, blurred vision and headaches-a malady known as Cybersickness. Cybersickness may be caused by a conflict between sensory signals for self-motion: while vision signals that the user is moving in a certain direction with certain acceleration, the vestibular organs provide no corroborating information. To resolve the sensory conflict, vestibular cues may be down-weighted leading to an alteration of how the brain interprets actual vestibular information. This may account for the frequently reported after-effects of VR exposure. Here, we investigated whether exposure to vection in VR modulates vestibular processing. We measured vestibular-evoked myogenic potentials (VEMPs) during brief immersion in a vection-inducing VR environment presented via head-mounted display. We found changes in VEMP asymmetry ratio, with a substantial increase in VEMP amplitude recorded on the left sternocleidomastoid muscle following just one minute of exposure to vection in VR. Our results suggest that exposure to vection in VR modulates vestibular processing, which may explain common after-effects of VR.
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Affiliation(s)
- Maria Gallagher
- Department of Psychology, Royal Holloway University of London, Egham, UK
| | - Ross Dowsett
- Department of Psychology, Royal Holloway University of London, Egham, UK
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Karnath HO, Mölbert SC, Klaner AK, Tesch J, Giel KE, Wong HY, Mohler BJ. Visual perception of one's own body under vestibular stimulation using biometric self-avatars in virtual reality. PLoS One 2019; 14:e0213944. [PMID: 30883577 PMCID: PMC6422330 DOI: 10.1371/journal.pone.0213944] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2018] [Accepted: 03/04/2019] [Indexed: 11/25/2022] Open
Abstract
BACKGROUND AND PURPOSE Vestibular input is projected to "multisensory (vestibular) cortex" where it converges with input from other sensory modalities. It has been assumed that this multisensory integration enables a continuous perception of state and presence of one's own body. The present study thus asked whether or not vestibular stimulation may impact this perception. METHODS We used an immersive virtual reality setup to realistically manipulate the length of extremities of first person biometric avatars. Twenty-two healthy participants had to adjust arms and legs to their correct length from various start lengths before, during, and after vestibular stimulation. RESULTS Neither unilateral caloric nor galvanic vestibular stimulation had a modulating effect on the perceived size of own extremities. CONCLUSION Our results suggest that vestibular stimulation does not directly influence the explicit somatosensory representation of our body. It is possible that in non-brain-damaged, healthy subjects, changes in whole body size perception are principally not mediated by vestibular information. Alternatively, visual feedback and/or memory may dominate multisensory integration and thereby override possibly existing modulations of body perception by vestibular stimulation. The present observations suggest that multisensory integration and not the processing of a single sensory input is the crucial mechanism in generating our body representation in relation to the external world.
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Affiliation(s)
- Hans-Otto Karnath
- Centre of Neurology, Division of Neuropsychology, Hertie-Institute for Clinical Brain Research, University of Tübingen, Tübingen, Germany
- Department of Psychology, University of South Carolina, Columbia, SC, United States of America
| | - Simone Claire Mölbert
- Centre of Neurology, Division of Neuropsychology, Hertie-Institute for Clinical Brain Research, University of Tübingen, Tübingen, Germany
- Medical University Hospital Tübingen, Dept. of Psychosomatic Medicine and Psychotherapy, University of Tübingen, Tübingen, Germany
- Max Planck Institute for Biological Cybernetics, Tübingen, Germany
| | - Anna Katharina Klaner
- Centre of Neurology, Division of Neuropsychology, Hertie-Institute for Clinical Brain Research, University of Tübingen, Tübingen, Germany
| | - Joachim Tesch
- Max Planck Institute for Biological Cybernetics, Tübingen, Germany
| | - Katrin Elisabeth Giel
- Medical University Hospital Tübingen, Dept. of Psychosomatic Medicine and Psychotherapy, University of Tübingen, Tübingen, Germany
| | - Hong Yu Wong
- Institute of Philosophy, University of Tübingen, Tübingen, Germany
| | - Betty J. Mohler
- Max Planck Institute for Biological Cybernetics, Tübingen, Germany
- Technical University Darmstadt, Institute of Sports Science, Darmstadt, Germany
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Hilber P, Cendelin J, Le Gall A, Machado ML, Tuma J, Besnard S. Cooperation of the vestibular and cerebellar networks in anxiety disorders and depression. Prog Neuropsychopharmacol Biol Psychiatry 2019; 89:310-321. [PMID: 30292730 DOI: 10.1016/j.pnpbp.2018.10.004] [Citation(s) in RCA: 44] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/04/2018] [Revised: 09/25/2018] [Accepted: 10/04/2018] [Indexed: 12/28/2022]
Abstract
The discipline of affective neuroscience is concerned with the neural bases of emotion and mood. The past decades have witnessed an explosion of research in affective neuroscience, increasing our knowledge of the brain areas involved in fear and anxiety. Besides the brain areas that are classically associated with emotional reactivity, accumulating evidence indicates that both the vestibular and cerebellar systems are involved not only in motor coordination but also influence both cognition and emotional regulation in humans and animal models. The cerebellar and the vestibular systems show the reciprocal connection with a myriad of anxiety and fear brain areas. Perception anticipation and action are also major centers of interest in cognitive neurosciences. The cerebellum is crucial for the development of an internal model of action and the vestibular system is relevant for perception, gravity-related balance, navigation and motor decision-making. Furthermore, there are close relationships between these two systems. With regard to the cooperation between the vestibular and cerebellar systems for the elaboration and the coordination of emotional cognitive and visceral responses, we propose that altering the function of one of the systems could provoke internal model disturbances and, as a result, anxiety disorders followed potentially with depressive states.
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Affiliation(s)
- Pascal Hilber
- Centre de Recherche sur les Fonctionnements et Dysfonctionnements Psychologigues, CRFDP EA 7475, Rouen Normandie University, Bat Blondel, Place E. Blondel 76821, Mont Saint Aignan cedex, France.
| | - Jan Cendelin
- Department of Pathophysiology, Faculty of Medicine in Pilsen, Charles University, alej Svobody 1655/76, 323 00 Plzen, Czech Republic; Laboratory of Neurodegenerative Disorders, Biomedical Center, Faculty of Medicine in Pilsen, Charles University, alej Svobody 1655/76, 323 00 Plzen, Czech Republic
| | - Anne Le Gall
- UMR UCBN/INSERM U 1075 COMETE, Pole des Formations et de Recherche en Sante, Normandie University, 2 Rue Rochambelles, 14032 Caen, cedex 5, France
| | - Marie-Laure Machado
- UMR UCBN/INSERM U 1075 COMETE, Pole des Formations et de Recherche en Sante, Normandie University, 2 Rue Rochambelles, 14032 Caen, cedex 5, France
| | - Jan Tuma
- Department of Pathophysiology, Faculty of Medicine in Pilsen, Charles University, alej Svobody 1655/76, 323 00 Plzen, Czech Republic; Laboratory of Neurodegenerative Disorders, Biomedical Center, Faculty of Medicine in Pilsen, Charles University, alej Svobody 1655/76, 323 00 Plzen, Czech Republic
| | - Stephane Besnard
- UMR UCBN/INSERM U 1075 COMETE, Pole des Formations et de Recherche en Sante, Normandie University, 2 Rue Rochambelles, 14032 Caen, cedex 5, France
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Holly JE, Cohen HS, Masood MA. Assessing misperception of rotation in benign paroxysmal positional vertigo with static and dynamic visual images. J Vestib Res 2019; 29:271-279. [PMID: 31450525 PMCID: PMC9973413 DOI: 10.3233/ves-190676] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
BACKGROUND Perception of self-motion is difficult for patients to describe. In addition, the relationship between perceived rotation and eye movements is poorly understood, because most studies of patients have investigated only static orientation. OBJECTIVE First, to determine whether patients with benign paroxysmal positional vertigo (BPPV) can use visual images to report perceived rotation elicited by the Dix-Hallpike maneuver. Second, to determine if the direction of patients' perceptions align with data on classical nystagmus direction. METHODS After the Dix-Hallpike maneuver, BPPV patients viewed images - sketches or video animations - representing possible perceived motions. They selected one or more images representing perception. RESULTS All subjects could select images. The directions of the videos were most often backward pitch and/ or ipsilateral roll and yaw relative to body orientation in the supine Dix-Hallpike position, generally consistent with the canal stimulus. Perceived direction of rotation was statistically significantly different from the direction of eye movements as published previously, suggesting a difference in mechanisms for perception and eye movements. CONCLUSION Patients can easily learn to use a video language to describe their experiences. Perception is generally aligned with canal stimulus and nystagmus, but not exactly.
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Affiliation(s)
- Jan E. Holly
- Department of Mathematics and Statistics, Colby College, Waterville, ME
| | - Helen S. Cohen
- Bobby R Alford Department of Otolaryngology – Head and Neck Surgery, Baylor College of Medicine, One Baylor Plaza, Houston, TX 77030
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Moro SS, Harris LR. Vestibular–somatosensory interactions affect the perceived timing of tactile stimuli. Exp Brain Res 2018; 236:2877-2885. [DOI: 10.1007/s00221-018-5346-8] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2017] [Accepted: 07/26/2018] [Indexed: 11/28/2022]
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Gallagher M, Ferrè ER. Cybersickness: a Multisensory Integration Perspective. Multisens Res 2018; 31:645-674. [PMID: 31264611 DOI: 10.1163/22134808-20181293] [Citation(s) in RCA: 45] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2017] [Accepted: 01/05/2018] [Indexed: 11/19/2022]
Abstract
In the past decade, there has been a rapid advance in Virtual Reality (VR) technology. Key to the user's VR experience are multimodal interactions involving all senses. The human brain must integrate real-time vision, hearing, vestibular and proprioceptive inputs to produce the compelling and captivating feeling of immersion in a VR environment. A serious problem with VR is that users may develop symptoms similar to motion sickness, a malady called cybersickness. At present the underlying cause of cybersickness is not yet fully understood. Cybersickness may be due to a discrepancy between the sensory signals which provide information about the body's orientation and motion: in many VR applications, optic flow elicits an illusory sensation of motion which tells users that they are moving in a certain direction with certain acceleration. However, since users are not actually moving, their proprioceptive and vestibular organs provide no cues of self-motion. These conflicting signals may lead to sensory discrepancies and eventually cybersickness. Here we review the current literature to develop a conceptual scheme for understanding the neural mechanisms of cybersickness. We discuss an approach to cybersickness based on sensory cue integration, focusing on the dynamic re-weighting of visual and vestibular signals for self-motion.
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Affiliation(s)
- Maria Gallagher
- Department of Psychology, Royal Holloway University of London, Egham, UK
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Harris LR, Sakurai K, Beaudot WHA. Tactile Flow Overrides Other Cues To Self Motion. Sci Rep 2017; 7:1059. [PMID: 28432328 PMCID: PMC5430733 DOI: 10.1038/s41598-017-01111-w] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2016] [Accepted: 03/22/2017] [Indexed: 11/09/2022] Open
Abstract
Vestibular-somatosensory interactions are pervasive in the brain but it remains unclear why. Here we explore the contribution of tactile flow to processing self-motion. We assessed two aspects of self-motion: timing and speed. Participants sat on an oscillating swing and either kept their hands on their laps or rested them lightly on an earth-stationary surface. They viewed a grating oscillating at the same frequency as their motion and judged its phase or, in a separate experiment, its speed relative to their perceived motion. Participants required the phase to precede body movement (with or without tactile flow) or tactile flow by ~5° (44 ms) to appear earth-stationary. Speed judgments were 4-10% faster when motion was from tactile flow, either alone or with body motion, compared to body motion alone (where speed judgments were accurate). By comparing response variances we conclude that phase and speed judgments do not reflect optimal integration of tactile flow with other cues to body motion: instead tactile flow dominates perceived self-motion - acting as an emergency override. This may explain why even minimal tactile cues are so helpful in promoting stability and suggests that providing artificial tactile cues might be a powerful aid to perceiving self-motion.
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Affiliation(s)
- Laurence R Harris
- Centre for Vision Research, York University, 4700 Keele St., Toronto, Ontario, M3J 1P3, Canada.
| | - Kenzo Sakurai
- Department of Human Science, Tohoku Gakuin University, 2-1-1 Tenjinzawa, Izumi-ku, Sendai, Miyagi, 981-3193, Japan.,Division of Human Informatics, Graduate School of Tohoku Gakuin University, 2-1-1 Tenjinzawa, Izumi-ku, Sendai, Miyagi, 981-3193, Japan.,KyberVision Japan LLC, 5-2-8 Takamori, Izumi-ku, Sendai, Miyagi, 981-3203, Japan
| | - William H A Beaudot
- Division of Human Informatics, Graduate School of Tohoku Gakuin University, 2-1-1 Tenjinzawa, Izumi-ku, Sendai, Miyagi, 981-3193, Japan.,KyberVision Japan LLC, 5-2-8 Takamori, Izumi-ku, Sendai, Miyagi, 981-3203, Japan
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