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Chen A, Kuo C, Blouin JS. A portable and low-cost solution for real-time manipulation of the vestibular sense. J Neurosci Methods 2022; 382:109709. [PMID: 36116537 DOI: 10.1016/j.jneumeth.2022.109709] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2022] [Revised: 09/02/2022] [Accepted: 09/06/2022] [Indexed: 01/05/2023]
Abstract
BACKGROUND The vestibular system encodes head motion in space which is naturally accompanied by other sensory cues. Electrical stimuli, applied across the mastoid processes, selectively activate primary vestibular afferents which has spurred clinical and biomedical applications of electrical vestibular stimulation (EVS). When properly matched to head motion, EVS may also manipulate the closed-loop relationship between actions and vestibular feedback to reveal the mechanisms of sensorimotor recalibration and learning. NEW METHOD We designed a portable, low-cost real-time EVS system using an Arduino microcontroller programmed through Simulink that provides electrical currents based on head angular motion. We used well-characterized vestibular afferent physiological responses to head angular velocity and electrical current to compute head-motion equivalent of real-time modulatory EVS currents. We also examined if our system induced recalibration of the vestibular system during human balance control. RESULTS Our system operated at 199.997 Hz ( ± 0.005 Hz) and delivered head-motion-equivalent electrical currents with ∼10 ms delay. The output driving the current stimulator matched the implemented linear model for physiological vestibular afferent dynamics with minimal background noise (<0.2% of ± 10 V range). Participants recalibrated to the modulated closed-loop vestibular feedback using visual cues during standing balance, replicating earlier findings. COMPARISON WITH EXISTING METHODS EVS is typically used to impose external perturbations that are independent of one's own movement. We provided a solution using open-source hardware to implement a real-time, physiology based, and task-relevant vestibular modulations using EVS. CONCLUSIONS Our portable, low-cost vestibular modulation system will make physiological closed-loop vestibular manipulations more accessible thus encouraging novel investigations and biomedical applications of EVS.
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Affiliation(s)
- Anthony Chen
- School of Kinesiology, University of British Columbia, Vancouver, Canada.
| | - Calvin Kuo
- School of Biomedical Engineering, University of British Columbia, Vancouver, Canada.
| | - Jean-Sébastien Blouin
- School of Kinesiology, University of British Columbia, Vancouver, Canada; Djavad Mowafaghian Centre for Brain Health, University of British Columbia, Vancouver, Canada; Institute for Computing, Information and Cognitive Systems, University of British Columbia, Vancouver, Canada.
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2
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Dureux A, Zigiotto L, Sarubbo S, Desoche C, Farnè A, Bolognini N, Hadj-Bouziane F. Personal space regulation is affected by unilateral temporal lesions beyond the amygdala. Cereb Cortex Commun 2022; 3:tgac031. [PMID: 36072709 PMCID: PMC9441012 DOI: 10.1093/texcom/tgac031] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2022] [Revised: 07/13/2022] [Accepted: 07/15/2022] [Indexed: 11/12/2022] Open
Abstract
Abstract
We constantly face situations involving interactions with others that require us to automatically adjust our physical distances to avoid discomfort or anxiety. A previous case study has demonstrated that the integrity of both amygdalae is essential to regulate interpersonal distances. Despite unilateral lesion to the amygdala, as to other sectors of the medial temporal cortex, are known to also affect social behavior, their role in the regulation of interpersonal distances has never been investigated. Here, we sought to fill this gap by testing three patients with unilateral temporal lesions following surgical resections, including one patient with a lesion mainly centered on the amygdala and two with lesions to adjacent medial temporal cortex, on two versions of the stop distance paradigm (i.e. in a virtual reality environment and in a real setting). Our results showed that all three patients set shorter interpersonal distances compared to neurotypical controls. In addition, compared to controls, none of the patients adjusted such physical distances depending on facial emotional expressions, despite they preserved ability to categorize them. Finally, patients' heart rate responses differed from controls when viewing approaching faces. Our findings bring compelling evidence that unilateral lesions within the medial temporal cortex, not necessarily restricted to the amygdala, are sufficient to alter interpersonal distance, thus shedding new light on the neural circuitry regulating distance in social interactions.
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Affiliation(s)
- Audrey Dureux
- Integrative Multisensory Perception Action & Cognition Team - ImpAct , INSERM U1028, CNRS UMR5292, , 69500 Lyon , France
- Neuroscience Research Center (CRNL) , INSERM U1028, CNRS UMR5292, , 69500 Lyon , France
- University UCBL Lyon 1, University of Lyon , 69622 Lyon , France
| | - Luca Zigiotto
- Department of Neurosurgery, Azienda Provinciale per i Servizi Sanitari (APSS), “Santa Chiara Hospital” , 38122 Trento , Italy
- Department of Psychology, Azienda Provinciale per i Servizi Sanitari (APSS), “Santa Chiara Hospital” , 38122 Trento , Italy
| | - Silvio Sarubbo
- Department of Neurosurgery, Azienda Provinciale per i Servizi Sanitari (APSS), “Santa Chiara Hospital” , 38122 Trento , Italy
| | - Clément Desoche
- University UCBL Lyon 1, University of Lyon , 69622 Lyon , France
- Hospices Civils de Lyon, Neuro-Immersion & Mouvement et Handicap , 69677 Lyon , France
| | - Alessandro Farnè
- Integrative Multisensory Perception Action & Cognition Team - ImpAct , INSERM U1028, CNRS UMR5292, , 69500 Lyon , France
- Neuroscience Research Center (CRNL) , INSERM U1028, CNRS UMR5292, , 69500 Lyon , France
- University UCBL Lyon 1, University of Lyon , 69622 Lyon , France
- Hospices Civils de Lyon, Neuro-Immersion & Mouvement et Handicap , 69677 Lyon , France
- Center for Mind/Brain Sciences (CIMeC), University of Trento , Trento , Italy
| | - Nadia Bolognini
- Department of Psychology, University of Milano Bicocca , 20126 Milano , Italy
- Laboratory of Neuropsychology, IRCCS Istituto Auxologico Italiano , 20122 Milano , Italy
| | - Fadila Hadj-Bouziane
- Integrative Multisensory Perception Action & Cognition Team - ImpAct , INSERM U1028, CNRS UMR5292, , 69500 Lyon , France
- Neuroscience Research Center (CRNL) , INSERM U1028, CNRS UMR5292, , 69500 Lyon , France
- University UCBL Lyon 1, University of Lyon , 69622 Lyon , France
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3
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Wang A, Lu F, Gao W, Zhang T, Zhang M. Reward Weakened Inhibition of Return (IOR) in the Near Depth Plane. Perception 2022; 51:114-130. [PMID: 35098807 DOI: 10.1177/03010066211073855] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
In attentional orienting, researchers have proposed that reward history is a component of attentional control, as the reward value might enhance the spatial attention process to achieve more efficient goal-directed behavior and to improve target-detection performance. Although the effect of reward-induced motivation on attentional orienting has been studied in two-dimensional (2-D) space, the specific mechanisms underlying the influence of reward on inhibition of return (IOR) of attentional orienting in three-dimensional space (3-D) remain unclear. In the present study, by incorporating the Posner spatial-cueing paradigm into a virtual 3-D environment, we aimed to investigate the influence of reward on IOR in 3-D space. The results showed the following: (1) IOR size in the rewarded conditions was smaller than IOR size in the unrewarded condition in the near depth plane, resulting in an IOR difference with or without reward. (2) Reward weakened IOR in the near depth plane because the response to the uncued location was delayed, not because the response to the cued location was accelerated. The present study indicated that the different depth planes of the target location in 3-D space could influence the interaction between reward and IOR, and reward weakened IOR in the near depth plane.
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4
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Felisatti A, Ranzini M, Blini E, Lisi M, Zorzi M. Effects of attentional shifts along the vertical axis on number processing: An eye-tracking study with optokinetic stimulation. Cognition 2021; 221:104991. [PMID: 34968993 DOI: 10.1016/j.cognition.2021.104991] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2021] [Revised: 11/06/2021] [Accepted: 12/10/2021] [Indexed: 11/25/2022]
Abstract
Previous studies suggest that associations between numbers and space are mediated by shifts of visuospatial attention along the horizontal axis. In this study, we investigated the effect of vertical shifts of overt attention, induced by optokinetic stimulation (OKS) and monitored through eye-tracking, in two tasks requiring explicit (number comparison) or implicit (parity judgment) processing of number magnitude. Participants were exposed to black-and-white stripes (OKS) that moved vertically (upward or downward) or remained static (control condition). During the OKS, participants were asked to verbally classify auditory one-digit numbers as larger/smaller than 5 (comparison task; Exp. 1) or as odd/even (parity task; Exp. 2). OKS modulated response times in both experiments. In Exp.1, upward attentional displacement decreased the Magnitude effect (slower responses for large numbers) and increased the Distance effect (slower responses for numbers close to the reference). In Exp.2, we observed a complex interaction between parity, magnitude, and OKS, indicating that downward attentional displacement slowed down responses for large odd numbers. Moreover, eye tracking analyses revealed an influence of number processing on eye movements both in Exp. 1, with eye gaze shifting downwards during the processing of small numbers as compared to large ones; and in Exp. 2, with leftward shifts after large even numbers (6,8) and rightward shifts after large odd numbers (7,9). These results provide evidence of bidirectional links between number and space and extend them to the vertical dimension. Moreover, they document the influence of visuo-spatial attention on processing of numerical magnitude, numerical distance, and parity. Together, our findings are in line with grounded and embodied accounts of numerical cognition.
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Affiliation(s)
| | | | - Elvio Blini
- Department of General Psychology, University of Padua, Italy
| | - Matteo Lisi
- Department of Psychology, University of Essex, UK
| | - Marco Zorzi
- Department of General Psychology, University of Padua, Italy; IRCCS San Camillo Hospital, Venice-Lido, Italy.
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5
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Suchting R, Teixeira AL, Ahn B, Colpo GD, Park J, Ahn H. Changes in Brain-derived Neurotrophic Factor From Active and Sham Transcranial Direct Current Stimulation in Older Adults With Knee Osteoarthritis. Clin J Pain 2021; 37:898-903. [PMID: 34757341 PMCID: PMC8589111 DOI: 10.1097/ajp.0000000000000987] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2021] [Accepted: 09/01/2021] [Indexed: 01/08/2023]
Abstract
OBJECTIVES Previous work has shown effects of transcranial direct current stimulation (tDCS) on clinical pain measures, qualitative sensory testing measures, and peripheral inflammation. The present report extends this research to investigate the effect of tDCS on brain-derived neurotrophic factor (BDNF) levels. MATERIALS AND METHODS This secondary analysis examined a sample of 40 older adults (50 to 70 y old) with symptomatic knee osteoarthritis randomly assigned in a 1:1 fashion to active (n=20) or sham (n=20) tDCS for 20 minutes on 5 consecutive days. BDNF was measured before the first session and after the final treatment session. Generalized linear modeling evaluated BDNF plasma levels as a function of tDCS group, adjusted for baseline. Bayesian statistical inference was used to quantify the probability that effects of the treatment exist. RESULTS Generalized linear modeling indicated a 90.4% posterior probability that the sham condition had 49.9% higher BDNF at the end of treatment, controlling for baseline. Follow-up analyses within the active TDCS group supported an association between change in BDNF and change in clinical pain, and exploratory analyses found an effect of tDCS on irisin. DISCUSSION Results indicated that tDCS could be a potential nonpharmacological treatment to decrease BDNF levels, which may in turn decrease pain. This study adds to a growing literature suggesting that tDCS affects cortical excitability, and consequentially, the neural circuits implicated in pain modulation. In addition to a direct connection to analgesia, BDNF changes may reflect tDCS-induced changes in different cortical areas and/or neural circuits.
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Affiliation(s)
- Robert Suchting
- UTHealth McGovern Medical School, Faillace Department of Psychiatry and Behavioral Sciences, University of Texas Health Science Center at Houston, Houston, TX, USA
| | - Antonio L. Teixeira
- UTHealth McGovern Medical School, Faillace Department of Psychiatry and Behavioral Sciences, University of Texas Health Science Center at Houston, Houston, TX, USA
| | - Brian Ahn
- UTHealth McGovern Medical School, Faillace Department of Psychiatry and Behavioral Sciences, University of Texas Health Science Center at Houston, Houston, TX, USA
| | - Gabriela D. Colpo
- UTHealth McGovern Medical School, Faillace Department of Psychiatry and Behavioral Sciences, University of Texas Health Science Center at Houston, Houston, TX, USA
| | - Juyoung Park
- College of Social Work & Criminal Justice, Phyllis and Harvey Sandler School of Social Work, Florida Atlantic University, Boca Raton, FL, USA
| | - Hyochol Ahn
- College of Nursing, Florida State University, Tallahassee, FL, USA
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6
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Friedl-Werner A, Machado ML, Balestra C, Liegard Y, Philoxene B, Brauns K, Stahn AC, Hitier M, Besnard S. Impaired Attentional Processing During Parabolic Flight. Front Physiol 2021; 12:675426. [PMID: 34054584 PMCID: PMC8155259 DOI: 10.3389/fphys.2021.675426] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2021] [Accepted: 04/09/2021] [Indexed: 11/19/2022] Open
Abstract
Previous studies suggest that altered gravity levels during parabolic flight maneuvers affect spatial updating. Little is known about the impact of the experimental setting and psychological stressors associated with parabolic flight experiments on attentional processes. To address this gap, we investigated the level of alertness, selective and sustained attention in 1 and 0 g using a Go/No-Go Continuous Performance Task. We also identified several parameters associated with the experimental set-up of a parabolic flight that could be expected to affect attentional processing. These included the use of scopolamine, sleep quality prior to the flight day, participant’s stress level as well as mood and anxiety state before and after the parabolic flight. We observed a deterioration in attentional processing prior to the first parabola that was further aggravated in weightlessness and returned to baseline after the last parabola. Reaction Time, Hit and False Alarm Rate were moderately correlated with self-reported anxiety state, but not cortisol levels or emotional states. The use of scopolamine had minor effects on Reaction Time. Our results confirm previous studies reporting impairments of cognitive performance in 0 g, and highlight important aspects that should be considered for the design of behavioral research experiments in future parabolic flight campaigns.
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Affiliation(s)
- Anika Friedl-Werner
- Charité - Universitätsmedizin Berlin, a Corporate Member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Institute of Physiology, Center for Space Medicine and Extreme Environments Berlin, Berlin, Germany.,Université de Normandie, INSERM U1075 COMETE, Caen, France
| | | | - Costantino Balestra
- Environmental, Occupational & Ageing "Integrative Physiology" Laboratory, Haute Ecole Bruxelles-Brabant, Brussels, Belgium.,DAN Europe Research Division (Roseto (It)-Brussels (B)), Brussels, Belgium
| | | | | | - Katharina Brauns
- Charité - Universitätsmedizin Berlin, a Corporate Member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Institute of Physiology, Center for Space Medicine and Extreme Environments Berlin, Berlin, Germany
| | - Alexander C Stahn
- Charité - Universitätsmedizin Berlin, a Corporate Member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Institute of Physiology, Center for Space Medicine and Extreme Environments Berlin, Berlin, Germany.,Unit of Experimental Psychiatry, Department of Psychiatry, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA, United States
| | - Martin Hitier
- Université de Normandie, INSERM U1075 COMETE, Caen, France.,Department of Otolaryngology Head and Neck Surgery, Centre Hospitalier Universitaire de Caen Normandie, Caen, France.,Department of Anatomy, Université de Normandie, Caen, France
| | - Stephane Besnard
- Université de Normandie, INSERM U1075 COMETE, Caen, France.,Aix Marseille Université, CNRS, UMR 7260, Laboratoire de Neurosciences Sensorielles et Cognitives - Equipe Physiopathologie et Thérapie des Désordres Vestibulaires, Marseille, France
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7
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Lee S, Liu A, McKeown MJ. Current perspectives on galvanic vestibular stimulation in the treatment of Parkinson's disease. Expert Rev Neurother 2021; 21:405-418. [PMID: 33621149 DOI: 10.1080/14737175.2021.1894928] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Introduction: Galvanic vestibular stimulation (GVS) is a noninvasive technique that activates vestibular afferents, influencing activity and oscillations in a broad network of brain regions. Several studies have suggested beneficial effects of GVS on motor symptoms in Parkinson's Disease (PD).Areas covered: A comprehensive overview of the stimulation techniques, potential mechanisms of action, challenges, and future research directions.Expert opinion: This emerging technology is not currently a viable therapy. However, a complementary therapy that is inexpensive, easily disseminated, customizable, and portable is sufficiently enticing that continued research and development is warranted. Future work utilizing biomedical engineering approaches, including concomitant functional neuroimaging, have the potential to significantly increase efficacy. GVS could be explored for other PD symptoms including orthostatic hypotension, dyskinesia, and sleep disorders.
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Affiliation(s)
- Soojin Lee
- Pacific Parkinson's Research Centre, University of British Columbia, Vancouver, Canada.,Wellcome Centre for Integrative Neuroimaging, FMRIB, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford UK
| | - Aiping Liu
- Department of Electronic Science and Technology, University of Science and Technology of China, Hefei, China
| | - Martin J McKeown
- Pacific Parkinson's Research Centre, University of British Columbia, Vancouver, Canada.,Department of Medicine, University of British Columbia, Vancouver, Canada
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8
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Close facial emotions enhance physiological responses and facilitate perceptual discrimination. Cortex 2021; 138:40-58. [PMID: 33677327 DOI: 10.1016/j.cortex.2021.01.014] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2020] [Revised: 09/22/2020] [Accepted: 01/26/2021] [Indexed: 11/21/2022]
Abstract
Accumulating evidence indicates that the peripersonal space (PPS) constitutes a privileged area for efficient processing of proximal stimuli, allowing to flexibly adapt our behavior both to the physical and social environment. Whether and how behavioral and physiological signatures of PPS relate to each other in emotional contexts remains, though, elusive. Here, we addressed this question by having participants to discriminate male from female faces depicting different emotions (happiness, anger or neutral) and presented at different distances (50 cm-300 cm) while we measured the reaction time and accuracy of their responses, as well as pupillary diameter, heart rate and heart rate variability. Results showed facilitation of participants' performances (i.e., faster response time) when faces were presented close compared to far from the participants, even when controlling for retinal size across distances. These behavioral effects were accompanied by significant modulation of participants' physiological indexes when faces were presented in PPS. Interestingly, both PPS representation and physiological signals were affected by features of the seen faces such as the emotional valence, its sex and the participants' sex, revealing the profound impact of social context onto the autonomic state and behavior within PPS. Together, these findings suggest that both external and internal signals contribute in shaping PPS representation.
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9
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Blini E, Tilikete C, Chelazzi L, Farnè A, Hadj-Bouziane F. The role of the vestibular system in value attribution to positive and negative reinforcers. Cortex 2020; 133:215-235. [PMID: 33130427 DOI: 10.1016/j.cortex.2020.09.004] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2020] [Revised: 09/03/2020] [Accepted: 09/03/2020] [Indexed: 01/06/2023]
Abstract
Somatic inputs originating from bioregulatory processes can guide cognition and behavior. One such bodily signal, mostly overlooked so far, is represented by visuo-vestibular coupling and its alteration, which in extreme cases may result in motion sickness. We argued that the inherently perturbed interoceptive state that follows can be a powerful determinant of human motivated behavior, resulting in a blunted response to appetitive stimuli and an exaggerated response to noxious ones. We sought to assess such differential impact of visuo-vestibular mismatches on value through a task involving conflict monitoring. We therefore administered to 42 healthy participants a modified version of the Flankers task, in which distractors (arrows, pointing in either a congruent or incongruent direction) signaled the availability of monetary incentives (gains, losses, or neutral trials). While performing the task, participants received either galvanic vestibular stimulation (GVS), or sham stimulation. We have found impaired behavioral performances when value, which was attached to task-irrelevant information, was at stake. Gains and losses, interestingly, dissociated, and only the latter caused enhanced interference costs in the task, suggesting that negative incentives may be more effective in capturing human attention than positive ones. Finally, we have found some weak evidence for GVS to further increase the processing of losses, as suggested by even larger interference costs in this condition. Results were, however, overall ambiguous, and suggest that much more research is needed to better understand the link between the vestibular system and motivation.
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Affiliation(s)
- Elvio Blini
- Integrative Multisensory Perception Action & Cognition Team (ImpAct), INSERM U1028, CNRS UMR5292, Lyon Neuroscience Research Center (CRNL), Lyon, France; University of Lyon, Lyon, France; Department of General Psychology, University of Padova, Padova, Italy.
| | - Caroline Tilikete
- Integrative Multisensory Perception Action & Cognition Team (ImpAct), INSERM U1028, CNRS UMR5292, Lyon Neuroscience Research Center (CRNL), Lyon, France; University of Lyon, Lyon, France; Hospices Civils de Lyon, Neuro-Ophthalmology and Neurocognition, Hôpital Neurologique Pierre Wertheimer, Bron, France
| | - Leonardo Chelazzi
- Department of Neuroscience, Biomedicine and Movement Sciences, University of Verona, Verona, Italy; National Institute of Neuroscience - Verona Unit, Verona, Italy
| | - Alessandro Farnè
- Integrative Multisensory Perception Action & Cognition Team (ImpAct), INSERM U1028, CNRS UMR5292, Lyon Neuroscience Research Center (CRNL), Lyon, France; University of Lyon, Lyon, France; Hospices Civils de Lyon, Neuro-Immersion Platform, Lyon, France
| | - Fadila Hadj-Bouziane
- Integrative Multisensory Perception Action & Cognition Team (ImpAct), INSERM U1028, CNRS UMR5292, Lyon Neuroscience Research Center (CRNL), Lyon, France; University of Lyon, Lyon, France.
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10
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Gammeri R, Iacono C, Ricci R, Salatino A. Unilateral Spatial Neglect After Stroke: Current Insights. Neuropsychiatr Dis Treat 2020; 16:131-152. [PMID: 32021206 PMCID: PMC6959493 DOI: 10.2147/ndt.s171461] [Citation(s) in RCA: 37] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/10/2019] [Accepted: 12/24/2019] [Indexed: 11/23/2022] Open
Abstract
INTRODUCTION Unilateral spatial neglect (USN) is a disorder of contralesional space awareness which often follows unilateral brain lesion. Since USN impairs awareness of contralesional space/body and often of concomitant motor disorders, its presence represents a negative prognostic factor of functional recovery. Thus, the disorder needs to be carefully diagnosed and treated. Here, we attempted to present a clear and concise picture of current insights in the comprehension and rehabilitation of USN. METHODS We first provided an updated overview of USN clinical and neuroanatomical features and then highlighted recent progresses in the diagnosis and rehabilitation of the disease. In relation to USN rehabilitation, we conducted a MEDLINE literature research on three of the most promising interventions for USN rehabilitation: prismatic adaptation (PA), non-invasive brain stimulation (NIBS), and virtual reality (VR). The identified studies were classified according to the strength of their methods. RESULTS The last years have witnessed a relative decrement of interest in the study of neuropsychological disorders of spatial awareness in USN, but a relative increase in the study of potential interventions for its rehabilitation. Although optimal protocols still need to be defined, high-quality studies have demonstrated the efficacy of PA, TMS and tDCS interventions for the treatment of USN. In addition, preliminary investigations are suggesting the potentials of GVS and VR approaches for USN rehabilitation. CONCLUSION Advancing neuropsychological and neuroscience tools to investigate USN pathophysiology is a necessary step to identify effective rehabilitation treatments and to foster our understanding of neurofunctional bases of spatial cognition in the healthy brain.
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Affiliation(s)
- Roberto Gammeri
- Department of Psychology, SAMBA (SpAtial, Motor and Bodily Awareness) Research Group, University of Turin, Turin, Italy
| | - Claudio Iacono
- Department of Psychology, SAMBA (SpAtial, Motor and Bodily Awareness) Research Group, University of Turin, Turin, Italy
| | - Raffaella Ricci
- Department of Psychology, SAMBA (SpAtial, Motor and Bodily Awareness) Research Group, University of Turin, Turin, Italy
- Neuroscience Institute of Turin (NIT), University of Turin, Turin, Italy
| | - Adriana Salatino
- Department of Psychology, SAMBA (SpAtial, Motor and Bodily Awareness) Research Group, University of Turin, Turin, Italy
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11
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Chen A, Khosravi-Hashemi N, Kuo C, Kramer JK, Blouin JS. Development of a conversion model between mechanical and electrical vestibular stimuli. J Neurophysiol 2019; 123:548-559. [PMID: 31851563 DOI: 10.1152/jn.00276.2019] [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] [Indexed: 11/22/2022] Open
Abstract
The vestibular end-organs encode for linear and angular head accelerations in space contributing to our internal representation of self-motion. Activation of the vestibular system with transmastoid electrical current has recently grown in popularity; however, a direct relationship between electrically evoked and mechanically evoked vestibular responses remains elusive in humans. We have developed and tested a mechanical-to-electrical vestibular stimulus conversion model incorporating physiological activation of primary vestibular afferents identified in nonhuman primates. We compared ocular torsional responses between mechanical (chair rotation) and model-derived electrical (binaural-bipolar) stimuli in separate experiments for an angular velocity step change (±10 deg/s over 1 s, ±4-mA peak amplitude; n = 10) and multisine angular velocities (±10 deg/s, 9.7 mA peak to peak, 0.05-1 Hz; n = 5), respectively. Perception of whole body rotation (n = 18) to our step-change stimuli was also evaluated. Ocular torsional slow-phase velocity responses between stimulation types were similar (paired two one-sided tests of equivalence: multiple P < 0.002; one-sample t test: P = 0.178) and correlated (Pearson's coefficient: multiple P < 0.001). Bootstrap analysis of perceived angular velocity likewise showed similarity in perceptual decay dynamics. These data suggest that central processing between stimuli was similar, and our vestibular stimulus conversion model with a conversion factor of ∼0.4 mA per deg/s for an angular velocity step change can generate electrical stimuli that replicates dynamic vestibular activation elicited by mechanical whole body rotations. This proposed vestibular conversion model represents an initial framework for using electrical stimuli to generate mechanically equivalent activation of primary vestibular afferents for use in biomedical applications and immersive reality technologies.NEW & NOTEWORTHY With the growing popularity of electrical vestibular stimulation in biomedical and immersive reality applications, a direct conversion model between electrical and mechanical vestibular stimuli is needed. We developed a model to generate electrical stimuli mimicking the physiological activation of vestibular afferents evoked by mechanical rotations. Ocular and perceptual responses evoked by mechanical and model-derived electrical stimuli were similar, thus providing a critical first step toward generation of electrically induced vestibular responses that have a realistic mechanical equivalent.
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Affiliation(s)
- A Chen
- School of Kinesiology, University of British Columbia, Vancouver, BC, Canada
| | - N Khosravi-Hashemi
- School of Kinesiology, University of British Columbia, Vancouver, BC, Canada.,International Collaboration on Repair Discoveries, University of British Columbia, Vancouver, BC, Canada
| | - C Kuo
- School of Kinesiology, University of British Columbia, Vancouver, BC, Canada.,Department of Computer Science, University of British Columbia, Vancouver, BC, Canada
| | - J K Kramer
- International Collaboration on Repair Discoveries, University of British Columbia, Vancouver, BC, Canada
| | - J-S Blouin
- School of Kinesiology, University of British Columbia, Vancouver, BC, Canada
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12
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Kwan A, Forbes PA, Mitchell DE, Blouin JS, Cullen KE. Neural substrates, dynamics and thresholds of galvanic vestibular stimulation in the behaving primate. Nat Commun 2019; 10:1904. [PMID: 31015434 PMCID: PMC6478681 DOI: 10.1038/s41467-019-09738-1] [Citation(s) in RCA: 67] [Impact Index Per Article: 13.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2018] [Accepted: 03/21/2019] [Indexed: 11/09/2022] Open
Abstract
Galvanic vestibular stimulation (GVS) uses the external application of electrical current to selectively target the vestibular system in humans. Despite its recent popularity for the assessment/treatment of clinical conditions, exactly how this non-invasive tool activates the vestibular system remains an open question. Here we directly investigate single vestibular afferent responses to GVS applied to the mastoid processes of awake-behaving monkeys. Transmastoid GVS produces robust and parallel activation of both canal and otolith afferents. Notably, afferent activation increases with intrinsic neuronal variability resulting in constant GVS-evoked neuronal detection thresholds across all afferents. Additionally, afferent tuning differs for GVS versus natural self-motion stimulation. Using a stochastic model of repetitive activity in afferents, we largely explain the main features of GVS-evoked vestibular afferent dynamics. Taken together, our results reveal the neural substrate underlying transmastoid GVS-evoked perceptual, ocular and postural responses-information that is essential to advance GVS applicability for biomedical uses in humans.
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Affiliation(s)
- Annie Kwan
- Department of Biomedical Engineering, McGill University, Montreal, QC, H3G 1Y6, Canada
| | - Patrick A Forbes
- Department of Neuroscience, Erasmus MC, University Medical Center Rotterdam, Rotterdam, 3000 CA, The Netherlands.,Department of BioMechanical Engineering, Delft University of Technology, Delft, 2628 CD, The Netherlands.,School of Kinesiology, University of British Columbia, Vancouver, BC, V6T 1Z1, Canada
| | - Diana E Mitchell
- Department of Physiology, McGill University, Montreal, QC, H3G 1Y6, Canada
| | - Jean-Sébastien Blouin
- School of Kinesiology, University of British Columbia, Vancouver, BC, V6T 1Z1, Canada
| | - Kathleen E Cullen
- Department of Physiology, McGill University, Montreal, QC, H3G 1Y6, Canada. .,Department of Biomedical Engineering, Johns Hopkins University, Baltimore, 21205, MD, USA.
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Bonato M, Romeo Z, Blini E, Pitteri M, Durgoni E, Passarini L, Meneghello F, Zorzi M. Ipsilesional Impairments of Visual Awareness After Right-Hemispheric Stroke. Front Psychol 2019; 10:697. [PMID: 31024378 PMCID: PMC6465520 DOI: 10.3389/fpsyg.2019.00697] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2018] [Accepted: 03/13/2019] [Indexed: 11/23/2022] Open
Abstract
Unilateral brain damage following stroke frequently hampers the processing of contralesional space. Whether and how it also affects the processing of stimuli appearing on the same side of the lesion is still poorly understood. Three main alternative hypotheses have been proposed, namely that ipsilesional processing is functionally (i) hyperefficient, (ii) impaired, or (iii) spared. Here, we investigated ipsilesional space awareness through a computerized paradigm that exploits a manipulation of concurrent information processing demands (i.e., multitasking). Twelve chronic right-hemisphere stroke patients with a total lack of awareness for the contralesional side of space were administered a task that required the spatial monitoring of two locations within the ipsilesional hemispace. Targets were presented immediately to the right of a central fixation point (3° eccentricity), or farther to the right toward the screen edge (17° eccentricity), or on both locations. Response to target position occurred either in isolation or while performing a concurrent visual or auditory task. Results showed that most errors occurred when two targets were simultaneously presented and patients were faced with additional task demands (in the visual or auditory modalities). In the context of concurrent visual load, ipsilesional targets presented at the rightmost location were omitted more frequently than those presented closer to fixation. This pattern qualifies ipsilesional processing in right-hemisphere stroke patients as functionally impaired, arguing against the notion of ipsilesional hyperperformance, especially when under visual load.
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Affiliation(s)
- Mario Bonato
- Department of General Psychology and Padova Neuroscience Center, University of Padua, Padua, Italy
| | | | - Elvio Blini
- Integrative Multisensory Perception Action and Cognition Team, University Claude Bernard of Lyon, Lyon, France
| | - Marco Pitteri
- Neurology Section, Department of Neurosciences, Biomedicine and Movement Sciences, University of Verona, Verona, Italy
| | | | | | | | - Marco Zorzi
- Department of General Psychology and Padova Neuroscience Center, University of Padua, Padua, Italy.,IRCCS San Camillo Hospital, Venice, Italy
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