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Brink A, Keramidas ME, Bergsten E, Eiken O. Influence of spatial orientation training in a centrifuge on the ability of fighter pilots to assess the bank angle during flight without visual references. J Neurophysiol 2024; 132:710-721. [PMID: 39015074 DOI: 10.1152/jn.00129.2024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2024] [Revised: 07/10/2024] [Accepted: 07/10/2024] [Indexed: 07/18/2024] Open
Abstract
Without visual references, nonpilots exposed to coordinated flight turns underestimate the bank angle, because of discordant information of the roll-angular displacement from the otoliths, consistently signaling vertical position, versus the semicircular canals, enabling detection of the displacement. Pilots may also use their ability to perceive the G load and knowledge of the relation between load and angle to assess the bank angle. Our aim was to investigate whether the perception of bank angle can be improved by spatial orientation training in a centrifuge. Sixteen pilots/pilot students assessed their roll tilt, in complete darkness, during both real coordinated flight turns and gondola centrifugation, at roll tilts of 30° and 60°. The experiments were repeated after a 3-wk period, during which eight of the subjects performed nine training sessions in the centrifuge, comprising feedback on roll angle vs. G load, and on indicating requested angles. Before training, the subjects perceived in the aircraft and centrifuge, respectively: 37 (17)°, 38 (14)° during 60° turns and 19 (12)°, 20 (10)° during 30° turns. Training improved the perception of angle during the 60° [to 60 (7)°, 55 (10)°; P ≤ 0.04] but not the 30° [21 (10)°, 15 (9)°; P ≥ 0.30] turns; the improvement disappeared within 2 yr after training. Angle assessments did not change in the untrained group. The results suggest that it is possible to, in a centrifuge, train a pilot's ability to perceive large but not discrete-to-moderate roll-angular displacements. The transient training effect is attributable to improved capacity to perceive and translate G load into roll angle and/or to increased reliance on semicircular canal signals.NEW & NOTEWORTHY Spatial disorientation is a major problem in aviation. When performing coordinated flight turns without external visual cues (e.g., flying in clouds or darkness), the pilot underestimates the aircraft bank angle because the vestibular system provides unreliable information of roll tilt. The present study demonstrates that it is possible to, in a long-arm centrifuge, train a pilot's ability to perceive large but not discrete-to-moderate roll-angular displacements.
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Affiliation(s)
- Andreas Brink
- Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden
- Division of Environmental Physiology, Swedish Aerospace Physiology Center, KTH Royal Institute of Technology, Stockholm, Sweden
| | - Michail E Keramidas
- Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden
- Division of Environmental Physiology, Swedish Aerospace Physiology Center, KTH Royal Institute of Technology, Stockholm, Sweden
| | - Eddie Bergsten
- Division of Environmental Physiology, Swedish Aerospace Physiology Center, KTH Royal Institute of Technology, Stockholm, Sweden
| | - Ola Eiken
- Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden
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Nakamura J, Kitazaki M. The effect of posture on virtual walking experience using foot vibrations. Sci Rep 2024; 14:19366. [PMID: 39169206 PMCID: PMC11339416 DOI: 10.1038/s41598-024-70229-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2024] [Accepted: 08/14/2024] [Indexed: 08/23/2024] Open
Abstract
Virtual walking systems for stationary observers have been developed using multimodal stimulation such as vision, touch, and sound to overcome physical limitation. In previous studies, participants were typically positioned in either a standing or a seated position. It would be beneficial if bedridden users could have enough virtual walking experience. Thus, we aimed to investigate the effects of participants' posture and foot vibrations on the experience of virtual walking. They were either sitting, standing, or lying during observing a virtual scene of a walking avatar in the first-person perspective, while vibrations either synchronized or asynchronized (randomized) to the avatar's walking were applied to their feet. We found that the synchronized foot vibrations improved virtual walking experiences compared to asynchronous vibrations. The standing position consistently offered an improved virtual walking experience compared to sitting and lying positions with either the synchronous or asynchronous foot vibrations, while the difference between the siting and lying postures was small and not significant. Furthermore, subjective scores for posture matching between real and virtual postures, illusory body ownership, and sense of agency were significantly higher with the synchronous than the asynchronous vibration. These findings suggest that experiencing virtual walking with foot vibrations in a lying position is less effective than a standing position, but not much different from a sitting position.
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Affiliation(s)
- Junya Nakamura
- Department of Computer Science and Engineering, Toyohashi University of Technology, 1-1 Hibarigaoka, Tempaku, Toyohashi, Aichi, 441-8580, Japan.
| | - Michiteru Kitazaki
- Department of Computer Science and Engineering, Toyohashi University of Technology, 1-1 Hibarigaoka, Tempaku, Toyohashi, Aichi, 441-8580, Japan.
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Allred AR, Lippert AF, Wood SJ. Galvanic Vestibular Stimulation Advancements for Spatial Disorientation Training. Aerosp Med Hum Perform 2024; 95:390-398. [PMID: 38915170 DOI: 10.3357/amhp.6362.2024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/26/2024]
Abstract
INTRODUCTION: Spatial disorientation (SD) remains the leading contributor to Class A mishaps in the U.S. Navy, consistent with historical trends. Despite this, SD training for military aircrew is largely confined to the classroom and experiential training replicating SD illusions is limited and infrequent. Static flight simulators are most commonly used for training but offer no vestibular stimulation to the flight crew, omitting the source of vestibular-mediated SD.BACKGROUND: We first cover vestibular-mediated SD illusions which may be replicated through galvanic vestibular stimulation (GVS) in a static environment. GVS is a safe, reliable, low-cost avenue for providing vestibular sensory stimulation. We review the underlying mechanisms of GVS such as the excitement and inhibition of the afferent neurons innervating the vestibular system, particularly in the binaural bipolar electrode montage.APPLICATIONS: Two approaches for how GVS may be used to enhance SD training are examined. The first is a means for providing unreliable vestibular sensory perceptions to pilots, and the second details how GVS can be leveraged for replicating vestibular-mediated SD illusions.DISCUSSION: We recommend GVS be pursued as an enhancement to existing SD training. The ability to disorient aircrew in the safe training environment of a static flight simulator would allow for aircrew familiarization to SD, serving as an opportunity to practice life-saving checklist items to recover from SD. A repeatable training profile that could be worn by military aircrew in a static flight simulator may afford a low-cost training solution to the number one cause of fatalities in military aviation.Allred AR, Lippert AF, Wood SJ. Galvanic vestibular stimulation advancements for spatial disorientation training. Aerosp Med Hum Perform. 2024; 95(7):390-398.
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Takeda T, Tajino J, Merfeld DM. Frequency dependence of human thresholds: both perceptual and vestibuloocular reflex thresholds. J Neurophysiol 2024; 131:1143-1155. [PMID: 38658179 DOI: 10.1152/jn.00224.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2023] [Revised: 04/24/2024] [Accepted: 04/24/2024] [Indexed: 04/26/2024] Open
Abstract
Although perceptual thresholds have been widely studied, vestibuloocular reflex (VOR) thresholds have received less attention, so the relationship between VOR and perceptual thresholds remains unclear. We compared the frequency dependence of human VOR thresholds to human perceptual thresholds for yaw head rotation in both upright ("yaw rotation") and supine ("yaw tilt") positions, using the same human subjects and motion device. VOR thresholds were generally a little smaller than perceptual thresholds. We also found that horizontal VOR thresholds for both yaw rotation about an Earth-vertical axis and yaw tilt (yaw rotation about an Earth-horizontal axis) were relatively constant across four frequencies (0.2, 0.5, 1, and 2 Hz), with little difference between yaw rotation and yaw tilt VOR thresholds. For yaw tilt stimuli, perceptual thresholds were slightly lower at the lowest frequency and nearly constant at all other (higher) frequencies. However, for yaw rotation, perceptual thresholds increased significantly at the lowest frequency (0.2 Hz). We conclude 1) that VOR thresholds were relatively constant across frequency for both yaw rotation and yaw tilt, 2) that the known contributions of velocity storage to the VOR likely yielded these VOR thresholds that were similar for yaw rotation and yaw tilt for all frequencies tested, and 3) that the integration of otolith and horizontal canal signals during yaw tilt when supine contributes to stable perceptual thresholds, especially relative to the low-frequency perceptual thresholds recorded during yaw rotation.NEW & NOTEWORTHY We describe for the first time that human VOR thresholds differ from human forced-choice perceptual thresholds, with the difference especially evident at frequencies below 0.5 Hz. We also report that VOR thresholds are relatively constant across frequency for both yaw rotation and yaw tilt. These findings are consistent with the idea that high-pass filtering in cortical pathways impacts cognitive decision-making.
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Affiliation(s)
- Takamori Takeda
- Department of Otolaryngology, The Ohio State University, Columbus, Ohio, United States
| | - Junichi Tajino
- Department of Otolaryngology, The Ohio State University, Columbus, Ohio, United States
| | - Daniel M Merfeld
- Department of Otolaryngology, The Ohio State University, Columbus, Ohio, United States
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Clark TK, Galvan-Garza RC, Merfeld DM. Intra-individual consistency of vestibular perceptual thresholds. Atten Percept Psychophys 2024; 86:1417-1434. [PMID: 38658516 DOI: 10.3758/s13414-024-02886-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/22/2024] [Indexed: 04/26/2024]
Abstract
Vestibular perceptual thresholds quantify sensory noise associated with reliable perception of small self-motions. Previous studies have identified substantial variation between even healthy individuals' thresholds. However, it remains unclear if or how an individual's vestibular threshold varies over repeated measures across various time scales (repeated measurements on the same day, across days, weeks, or months). Here, we assessed yaw rotation and roll tilt thresholds in four individuals and compared this intra-individual variability to inter-individual variability of thresholds measured across a large age-matched cohort each measured only once. For analysis, we performed simulations of threshold measurements where there was no underlying variability (or it was manipulated) to compare to that observed empirically. We found remarkable consistency in vestibular thresholds within individuals, for both yaw rotation and roll tilt; this contrasts with substantial inter-individual differences. Thus, we conclude that vestibular perceptual thresholds are an innate characteristic, which validates pooling measures across sessions and potentially serves as a stable clinical diagnostic and/or biomarker.
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Affiliation(s)
- Torin K Clark
- Jenks Vestibular Physiology Lab, Massachusetts Eye and Ear Infirmary, Department of Otology and Laryngology, Harvard Medical School, Boston, MA, USA.
- Man Vehicle Laboratory, Department of Aeronautics and Astronautics, Massachusetts Institute of Technology, Cambridge, MA, USA.
- Bioastronautics Laboratory, Smead Aerospace Engineering Sciences, University of Colorado-Boulder, 3375 Discovery Dr. AERO N301, Boulder, CO, 80309, USA.
| | - Raquel C Galvan-Garza
- Jenks Vestibular Physiology Lab, Massachusetts Eye and Ear Infirmary, Department of Otology and Laryngology, Harvard Medical School, Boston, MA, USA
- Man Vehicle Laboratory, Department of Aeronautics and Astronautics, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Daniel M Merfeld
- Jenks Vestibular Physiology Lab, Massachusetts Eye and Ear Infirmary, Department of Otology and Laryngology, Harvard Medical School, Boston, MA, USA
- Otolaryngology-Head & Neck Surgery, The Ohio State University, Columbus, OH, USA
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Brink A, Keramidas ME, Tribukait A, Eiken O. Factors of significance for the ability of fighter pilots to visually indicate the magnitude of roll tilt during simulated turns in a centrifuge. Perception 2024; 53:75-92. [PMID: 37946509 PMCID: PMC10798017 DOI: 10.1177/03010066231209847] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2023] [Accepted: 10/06/2023] [Indexed: 11/12/2023]
Abstract
During coordinated flight and centrifugation, pilots show interindividual variability in perceived roll tilt. The study explored how this variability is related to perceptual and cognitive functions. Twelve pilots underwent three 6-min centrifugations on two occasions (G levels: 1.1G, 1.8G, and 2.5G; gondola tilts: 25°, 56°, and 66°). The subjective visual horizontal (SVH) was measured with an adjustable luminous line and the pilots gave estimates of experienced G level. Afterward, they were interrogated regarding the relationship between G level and roll tilt and adjusted the line to numerically mentioned angles. Generally, the roll tilt during centrifugation was underestimated, and there was a large interindividual variability. Both knowledge on the relationship between G level and bank angle, and ability to adjust the line according to given angles contributed to the prediction of SVH in a multiple regression model. However, in most cases, SVH was substantial smaller than predictions based on specific abilities.
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Affiliation(s)
- Andreas Brink
- Division of Environmental Physiology, Swedish Aerospace Physiology Center, KTH Royal Institute of Technology, Stockholm, Sweden
| | - Michail E Keramidas
- Division of Environmental Physiology, Swedish Aerospace Physiology Center, KTH Royal Institute of Technology, Stockholm, Sweden
| | - Arne Tribukait
- Department of Clinical Neuroscience, Section for Eye and Vision, Karolinska Institute, Stockholm, Sweden
| | - Ola Eiken
- Division of Environmental Physiology, Swedish Aerospace Physiology Center, KTH Royal Institute of Technology, Stockholm, Sweden
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Kobel MJ, Wagner AR, Oas JG, Merfeld DM. Characterization of Vestibular Perception in Patients with Persistent Postural-Perceptual Dizziness. Otol Neurotol 2024; 45:75-82. [PMID: 38013457 DOI: 10.1097/mao.0000000000004053] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2023]
Abstract
OBJECTIVE To assess vestibular (i.e., passive self-motion) perception in patients diagnosed with persistent postural-perceptual dizziness (PPPD). STUDY DESIGN Case-controlled, cross-sectional, observational investigation. SETTING Single-center laboratory-based study. PATIENTS Thirteen patients with PPPD, 13 age-matched healthy control volunteers. Of those with PPPD, eight had co-occurring vestibular migraine (VM). INTERVENTIONS All participants completed a vestibular threshold test battery reflecting perception with predominant inputs from ( a ) the otoliths (1-Hz interaural y -axis translation, 1-Hz superior-inferior z -axis translation), ( b ) the semicircular canals (2-Hz yaw rotation, 2-Hz tilts in the planes of the vertical canal pairs), and ( c ) and canal-otolith integration (0.5-Hz roll tilt). MAIN OUTCOME MEASURES Direction-recognition thresholds for each vestibular threshold test condition. RESULTS Across all patients with PPPD, higher thresholds for superior-inferior z -translations thresholds in comparison to age-matched healthy control participants were identified ( p < 0.001). Those patients with co-occurring VM and PPPD (PPPD/+VM) displayed significantly higher z -translation thresholds ( p = 0.006), whereas patients with PPPD without VM (PPPD/-VM) displayed significantly higher roll tilt thresholds ( p = 0.029). CONCLUSIONS Patients with PPPD did not display a global worsening of passive self-motion perception as quantified by vestibular perceptual thresholds. Instead, patients with PPPD displayed elevated thresholds for only roll tilt and z -translation thresholds, with the relative change in each threshold impacted by the co-occurrence of VM. Because both z -translation and roll tilt motions are reliant on accurate gravity perception, our data suggest that patients with PPPD may exhibit impaired processing of graviceptive cues.
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Affiliation(s)
- Megan J Kobel
- Department of Otolaryngology-Head and Neck Surgery, The Ohio State University Wexner Medical Center, Columbus
| | - Andrew R Wagner
- Department of Otolaryngology-Head and Neck Surgery, The Ohio State University Wexner Medical Center, Columbus
| | - John G Oas
- Naval Aerospace Medical Research Laboratory, Naval Medical Research Unit-Dayton, Dayton, Ohio
| | - Daniel M Merfeld
- Department of Otolaryngology-Head and Neck Surgery, The Ohio State University Wexner Medical Center, Columbus
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Fitze DC, Mast FW, Ertl M. Human vestibular perceptual thresholds - A systematic review of passive motion perception. Gait Posture 2024; 107:83-95. [PMID: 37778297 DOI: 10.1016/j.gaitpost.2023.09.011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/30/2022] [Revised: 09/12/2023] [Accepted: 09/19/2023] [Indexed: 10/03/2023]
Abstract
BACKGROUND The vestibular system detects head accelerations within 6 degrees of freedom. How well this is accomplished is described by vestibular perceptual thresholds. They are a measure of perceptual performance based on the conscious evaluation of sensory information. This review provides an integrative synthesis of the vestibular perceptual thresholds reported in the literature. The focus lies on the estimation of thresholds in healthy participants, used devices and stimulus profiles. The dependence of these thresholds on the participants clinical status and age is also reviewed. Furthermore, thresholds from primate studies are discussed. RESULTS Thresholds have been measured for frequencies ranging from 0.05 to 5 Hz. They decrease with increasing frequency for five of the six main degrees of freedom (inter-aural, head-vertical, naso-occipital, yaw, pitch). No consistent pattern is evident for roll rotations. For a frequency range beyond 5 Hz, a U-shaped relationship is suggested by a qualitative comparison to primate data. Where enough data is available, increasing thresholds with age and higher thresholds in patients compared to healthy controls can be observed. No effects related to gender or handedness are reported. SIGNIFICANCE Vestibular thresholds are essential for next generation screening tools in the clinical domain, for the assessment of athletic performance, and workplace safety alike. Knowledge about vestibular perceptual thresholds contributes to basic and applied research in fields such as perception, cognition, learning, and healthy aging. This review provides normative values for vestibular thresholds. Gaps in current knowledge are highlighted and attention is drawn to specific issues for improving the inter-study comparability in the future.
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Affiliation(s)
- Daniel C Fitze
- Department of Psychology, University of Bern, Fabrikstrasse 8, 3012, Bern, Switzerland.
| | - Fred W Mast
- Department of Psychology, University of Bern, Fabrikstrasse 8, 3012, Bern, Switzerland.
| | - Matthias Ertl
- Department of Psychology, University of Bern, Fabrikstrasse 8, 3012, Bern, Switzerland.
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Geno O, Critelli K, Arduino C, Crane BT, Anson ER. Psychometrics of inertial heading perception. J Vestib Res 2024; 34:83-92. [PMID: 38640182 DOI: 10.3233/ves-230077] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/21/2024]
Abstract
BACKGROUND Inertial self-motion perception is thought to depend primarily on otolith cues. Recent evidence demonstrated that vestibular perceptual thresholds (including inertial heading) are adaptable, suggesting novel clinical approaches for treating perceptual impairments resulting from vestibular disease. OBJECTIVE Little is known about the psychometric properties of perceptual estimates of inertial heading like test-retest reliability. Here we investigate the psychometric properties of a passive inertial heading perceptual test. METHODS Forty-seven healthy subjects participated across two visits, performing in an inertial heading discrimination task. The point of subjective equality (PSE) and thresholds for heading discrimination were identified for the same day and across day tests. Paired t-tests determined if the PSE or thresholds significantly changed and a mixed interclass correlation coefficient (ICC) model examined test-retest reliability. Minimum detectable change (MDC) was calculated for PSE and threshold for heading discrimination. RESULTS Within a testing session, the heading discrimination PSE score test-retest reliability was good (ICC = 0. 80) and did not change (t(1,36) = -1.23, p = 0.23). Heading discrimination thresholds were moderately reliable (ICC = 0.67) and also stable (t(1,36) = 0.10, p = 0.92). Across testing sessions, heading direction PSE scores were moderately correlated (ICC = 0.59) and stable (t(1,46) = -0.44, p = 0.66). Heading direction thresholds had poor reliability (ICC = 0.03) and were significantly smaller at the second visit (t(1,46) = 2.8, p = 0.008). MDC for heading direction PSE ranged from 6-9 degrees across tests. CONCLUSION The current results indicate moderate reliability for heading perception PSE and provide clinical context for interpreting change in inertial vestibular self-motion perception over time or after an intervention.
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Affiliation(s)
- Olivia Geno
- Department of Neuroscience, University of Rochester, Rochester NY, USA
| | - Kyle Critelli
- Department of Otolaryngology, University of Rochester, Rochester NY, USA
| | - Cesar Arduino
- Department of Otolaryngology, University of Rochester, Rochester NY, USA
| | - Benjamin T Crane
- Department of Neuroscience, University of Rochester, Rochester NY, USA
- Department of Otolaryngology, University of Rochester, Rochester NY, USA
| | - Eric R Anson
- Department of Neuroscience, University of Rochester, Rochester NY, USA
- Department of Otolaryngology, University of Rochester, Rochester NY, USA
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Grove CR, Klatt BN, Wagner AR, Anson ER. Vestibular perceptual testing from lab to clinic: a review. Front Neurol 2023; 14:1265889. [PMID: 37859653 PMCID: PMC10583719 DOI: 10.3389/fneur.2023.1265889] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2023] [Accepted: 09/18/2023] [Indexed: 10/21/2023] Open
Abstract
Not all dizziness presents as vertigo, suggesting other perceptual symptoms for individuals with vestibular disease. These non-specific perceptual complaints of dizziness have led to a recent resurgence in literature examining vestibular perceptual testing with the aim to enhance clinical diagnostics and therapeutics. Recent evidence supports incorporating rehabilitation methods to retrain vestibular perception. This review describes the current field of vestibular perceptual testing from scientific laboratory techniques that may not be clinic friendly to some low-tech options that may be more clinic friendly. Limitations are highlighted suggesting directions for additional research.
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Affiliation(s)
- Colin R. Grove
- Department of Otolaryngology Head and Neck Surgery, Johns Hopkins University School of Medicine, Baltimore, MD, United States
- Division of Physical Therapy, Department of Physical Medicine and Rehabilitation School of Medicine, Emory University, Atlanta, GA, United States
| | - Brooke N. Klatt
- Physical Therapy Department, University of Pittsburgh, Pittsburgh, PA, United States
| | - Andrew R. Wagner
- Department of Otolaryngology—Head and Neck Surgery, Ohio State University Wexner Medical Center, Columbus, OH, United States
- School of Health and Rehabilitation Sciences, Ohio State University, Columbus, OH, United States
| | - Eric R. Anson
- Department of Otolaryngology, University of Rochester, Rochester, NY, United States
- Physical Therapy Department, University of Rochester, Rochester, NY, United States
- Department of Neuroscience, University of Rochester, Rochester, NY, United States
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Wagner AR, Kobel MJ, Merfeld DM. Increased roll tilt thresholds are associated with subclinical postural instability in asymptomatic adults aged 21 to 84 years. Front Aging Neurosci 2023; 15:1207711. [PMID: 37637958 PMCID: PMC10448770 DOI: 10.3389/fnagi.2023.1207711] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2023] [Accepted: 07/17/2023] [Indexed: 08/29/2023] Open
Abstract
Background Balance assessments that intentionally alter the reliability of visual and proprioceptive feedback (e.g., standing on foam with eyes closed) have become a standard approach for identifying vestibular mediated balance dysfunction in older adults. However, such assessments cannot discern which specific element of the vestibular system (e.g., semicircular canal, otolith, or combined canal-otolith) underlies the observed age-related changes in balance performance. The present study was designed to determine the associations between specific sources of vestibular noise and quantitative measures of quiet stance postural control measured during standard "vestibular" balance conditions. Methods A group of 52 asymptomatic adults (53.21 ± 19.7, 21 to 84 years) without a history of vestibular or neurologic disorders volunteered for this study. We measured a battery of five vestibular perceptual thresholds that assay vestibular noise with predominant contributions from the vertical canals, lateral canals, utricles, saccules, and the centrally integrated canal-otolith signal. In addition, participants completed two standard balance assessments that were each designed to prioritize the use of vestibular cues for quiet stance postural control-eyes closed on foam (Condition 4 of the Modified Romberg Balance Test) and eyes closed, on a sway referenced support surface (Condition 5 of the Sensory Organization Test). Results In age adjusted models, we found strong positive associations between roll tilt vestibular thresholds, a measure of noise in the centrally integrated canal-otolith signal, and the root mean square distance (RMSD) of the anteroposterior and mediolateral center of pressure (CoP) captured during eyes closed stance on a sway referenced support surface. The strength of the association between roll tilt thresholds and the RMSD of the CoP was between 3-times and 30-times larger than the association between postural sway and each of the other vestibular thresholds measured. Conclusion We posit that noise in the centrally estimated canal-otolith "tilt" signal may be the primary driver of the subclinical postural instability experienced by older adults during the "vestibular" conditions of balance assessments. Additional testing in adults with clinical balance impairment are needed to identify if roll tilt thresholds may also serve as a surrogate metric by which to detect vestibular mediated balance dysfunction and/or fall risk.
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Affiliation(s)
- Andrew R. Wagner
- Department of Otolaryngology – Head and Neck Surgery, Ohio State University Wexner Medical Center, Columbus, OH, United States
- School of Health and Rehabilitation Sciences, The Ohio State University, Columbus, OH, United States
| | - Megan J. Kobel
- Department of Otolaryngology – Head and Neck Surgery, Ohio State University Wexner Medical Center, Columbus, OH, United States
- Department of Speech and Hearing Science, The Ohio State University, Columbus, OH, United States
| | - Daniel M. Merfeld
- Department of Otolaryngology – Head and Neck Surgery, Ohio State University Wexner Medical Center, Columbus, OH, United States
- School of Health and Rehabilitation Sciences, The Ohio State University, Columbus, OH, United States
- Department of Speech and Hearing Science, The Ohio State University, Columbus, OH, United States
- Department of Biomedical Engineering, The Ohio State University, Columbus, OH, United States
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12
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Kobel MJ, Wagner AR, Merfeld DM. Evaluating vestibular contributions to rotation and tilt perception. Exp Brain Res 2023; 241:1873-1885. [PMID: 37310477 PMCID: PMC11161027 DOI: 10.1007/s00221-023-06650-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2023] [Accepted: 05/30/2023] [Indexed: 06/14/2023]
Abstract
Vestibular perceptual thresholds provide insights into sensory function and have shown clinical and functional relevance. However, specific sensory contributions to tilt and rotation thresholds have been incompletely characterized. To address this limitation, tilt thresholds (i.e., rotations about earth-horizontal axes) were quantified to assess canal-otolith integration, and rotation thresholds (i.e., rotations about earth-vertical axes) were quantified to assess perception mediated predominantly by the canals. To determine the maximal extent to which non-vestibular sensory cues (e.g., tactile) can contribute to tilt and rotation thresholds, we tested two patients with completely absent vestibular function and compared their data to those obtained from two separate cohorts of young (≤ 40 years), healthy adults. As one primary finding, thresholds for all motions were elevated by approximately 2-35 times in the absence of vestibular function, thus, confirming predominant vestibular contributions to both rotation and tilt self-motion perception. For patients without vestibular function, rotation thresholds showed larger increases relative to healthy adults than tilt thresholds. This suggests that increased extra-vestibular (e.g., tactile or interoceptive) sensory cues may contribute more to the perception of tilt than rotation. In addition, an impact of stimulus frequency was noted, suggesting increased vestibular contributions relative to other sensory systems can be targeted on the basis of stimulus frequency.
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Affiliation(s)
- Megan J Kobel
- Otolaryngology-Head and Neck Surgery, Ohio State University Wexner Medical Center, Columbus, OH, USA.
| | - Andrew R Wagner
- Otolaryngology-Head and Neck Surgery, Ohio State University Wexner Medical Center, Columbus, OH, USA
| | - Daniel M Merfeld
- Otolaryngology-Head and Neck Surgery, Ohio State University Wexner Medical Center, Columbus, OH, USA
- Speech and Hearing Science, Ohio State University, Columbus, OH, USA
- Health and Rehabilitation Sciences, Ohio State University, Columbus, OH, USA
- Biomedical Engineering, Ohio State University, Columbus, OH, USA
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Irmak T, Pool DM, de Winkel KN, Happee R. Validating models of sensory conflict and perception for motion sickness prediction. BIOLOGICAL CYBERNETICS 2023; 117:185-209. [PMID: 36971844 DOI: 10.1007/s00422-023-00959-8] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/29/2022] [Accepted: 03/05/2023] [Indexed: 06/13/2023]
Abstract
The human motion perception system has long been linked to motion sickness through state estimation conflict terms. However, to date, the extent to which available perception models are able to predict motion sickness, or which of the employed perceptual mechanisms are of most relevance to sickness prediction, has not been studied. In this study, the subjective vertical model, the multi-sensory observer model and the probabilistic particle filter model were all validated for their ability to predict motion perception and sickness, across a large set of motion paradigms of varying complexity from literature. It was found that even though the models provided a good match for the perception paradigms studied, they could not be made to capture the full range of motion sickness observations. The resolution of the gravito-inertial ambiguity has been identified to require further attention, as key model parameters selected to match perception data did not optimally match motion sickness data. Two additional mechanisms that may enable better future predictive models of sickness have, however, been identified. Firstly, active estimation of the magnitude of gravity appears to be instrumental for predicting motion sickness induced by vertical accelerations. Secondly, the model analysis showed that the influence of the semicircular canals on the somatogravic effect may explain the differences in the dynamics observed for motion sickness induced by vertical and horizontal plane accelerations.
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Affiliation(s)
- Tugrul Irmak
- Delft University of Technology Cognitive Robotics Department, Leeghwaterstraat, Delft, The Netherlands.
| | - Daan M Pool
- Delft University of Technology Cognitive Robotics Department, Leeghwaterstraat, Delft, The Netherlands
- Control and Simulation Department, Delft University of Technology, Leeghwaterstraat, Delft, The Netherlands
| | - Ksander N de Winkel
- Delft University of Technology Cognitive Robotics Department, Leeghwaterstraat, Delft, The Netherlands
| | - Riender Happee
- Delft University of Technology Cognitive Robotics Department, Leeghwaterstraat, Delft, The Netherlands
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14
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Lacquaniti F, La Scaleia B, Zago M. Noise and vestibular perception of passive self-motion. Front Neurol 2023; 14:1159242. [PMID: 37181550 PMCID: PMC10169592 DOI: 10.3389/fneur.2023.1159242] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2023] [Accepted: 03/29/2023] [Indexed: 05/16/2023] Open
Abstract
Noise defined as random disturbances is ubiquitous in both the external environment and the nervous system. Depending on the context, noise can degrade or improve information processing and performance. In all cases, it contributes to neural systems dynamics. We review some effects of various sources of noise on the neural processing of self-motion signals at different stages of the vestibular pathways and the resulting perceptual responses. Hair cells in the inner ear reduce the impact of noise by means of mechanical and neural filtering. Hair cells synapse on regular and irregular afferents. Variability of discharge (noise) is low in regular afferents and high in irregular units. The high variability of irregular units provides information about the envelope of naturalistic head motion stimuli. A subset of neurons in the vestibular nuclei and thalamus are optimally tuned to noisy motion stimuli that reproduce the statistics of naturalistic head movements. In the thalamus, variability of neural discharge increases with increasing motion amplitude but saturates at high amplitudes, accounting for behavioral violation of Weber's law. In general, the precision of individual vestibular neurons in encoding head motion is worse than the perceptual precision measured behaviorally. However, the global precision predicted by neural population codes matches the high behavioral precision. The latter is estimated by means of psychometric functions for detection or discrimination of whole-body displacements. Vestibular motion thresholds (inverse of precision) reflect the contribution of intrinsic and extrinsic noise to perception. Vestibular motion thresholds tend to deteriorate progressively after the age of 40 years, possibly due to oxidative stress resulting from high discharge rates and metabolic loads of vestibular afferents. In the elderly, vestibular thresholds correlate with postural stability: the higher the threshold, the greater is the postural imbalance and risk of falling. Experimental application of optimal levels of either galvanic noise or whole-body oscillations can ameliorate vestibular function with a mechanism reminiscent of stochastic resonance. Assessment of vestibular thresholds is diagnostic in several types of vestibulopathies, and vestibular stimulation might be useful in vestibular rehabilitation.
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Affiliation(s)
- Francesco Lacquaniti
- Laboratory of Neuromotor Physiology, IRCCS Santa Lucia Foundation, Rome, Italy
- Department of Systems Medicine, Centre of Space Bio-medicine, University of Rome Tor Vergata, Rome, Italy
| | - Barbara La Scaleia
- Laboratory of Neuromotor Physiology, IRCCS Santa Lucia Foundation, Rome, Italy
| | - Myrka Zago
- Laboratory of Neuromotor Physiology, IRCCS Santa Lucia Foundation, Rome, Italy
- Department of Civil Engineering and Computer Science Engineering, Centre of Space Bio-medicine, University of Rome Tor Vergata, Rome, Italy
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15
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Sinnott CB, Hausamann PA, MacNeilage PR. Natural statistics of human head orientation constrain models of vestibular processing. Sci Rep 2023; 13:5882. [PMID: 37041176 PMCID: PMC10090077 DOI: 10.1038/s41598-023-32794-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2022] [Accepted: 04/02/2023] [Indexed: 04/13/2023] Open
Abstract
Head orientation relative to gravity determines how gravity-dependent environmental structure is sampled by the visual system, as well as how gravity itself is sampled by the vestibular system. Therefore, both visual and vestibular sensory processing should be shaped by the statistics of head orientation relative to gravity. Here we report the statistics of human head orientation during unconstrained natural activities in humans for the first time, and we explore implications for models of vestibular processing. We find that the distribution of head pitch is more variable than head roll and that the head pitch distribution is asymmetrical with an over-representation of downward head pitch, consistent with ground-looking behavior. We further suggest that pitch and roll distributions can be used as empirical priors in a Bayesian framework to explain previously measured biases in perception of both roll and pitch. Gravitational and inertial acceleration stimulate the otoliths in an equivalent manner, so we also analyze the dynamics of human head orientation to better understand how knowledge of these dynamics can constrain solutions to the problem of gravitoinertial ambiguity. Gravitational acceleration dominates at low frequencies and inertial acceleration dominates at higher frequencies. The change in relative power of gravitational and inertial components as a function of frequency places empirical constraints on dynamic models of vestibular processing, including both frequency segregation and probabilistic internal model accounts. We conclude with a discussion of methodological considerations and scientific and applied domains that will benefit from continued measurement and analysis of natural head movements moving forward.
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Affiliation(s)
| | - Peter A Hausamann
- Department of Electrical and Computer Engineering, Technical University of Munich, 80333, Munich, Germany
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16
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Allred AR, Clark TK. Vestibular perceptual thresholds for rotation about the yaw, roll, and pitch axes. Exp Brain Res 2023; 241:1101-1115. [PMID: 36871088 DOI: 10.1007/s00221-023-06570-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2022] [Accepted: 02/07/2023] [Indexed: 03/06/2023]
Abstract
This effort seeks to further assess human perception of self-motion by quantifying and comparing earth-vertical rotational vestibular perceptual thresholds about the yaw, roll, and pitch axes. Early seminal works (Benson Aviat Space Environ Med 60:205-213, 1989) quantified thresholds for yaw, roll, and pitch rotations, using single-cycle sinusoids in angular acceleration with a frequency of 0.3 Hz (3.33 s motion duration) and found yaw thresholds to be significantly lower than roll and pitch thresholds (1.58-1.20 deg/s vs. 2.07 deg/s and 2.04 deg/s, respectively). Our current effort uses modern methods and definitions to reassess if rotational thresholds differ between these three axes of rotation in ten human subjects at 0.3 Hz and additionally across a range of frequencies: 0.1 Hz, 0.3 Hz, and 0.5 Hz. In contrast to the established findings of Benson et al., no statistically significant differences were found between the three rotational axes at 0.3 Hz. Further, no statistically significant differences were found at any of these frequencies. Instead, a consistent pattern was found for yaw, pitch, and roll of increasing thresholds with decreasing rotational frequency, consistent with the brain employing high-pass filter mechanisms for decision-making. We also fill a gap in the literature by extending the quantification of pitch rotation thresholds to 0.1 Hz. Finally, we assessed inter-individual trends between these three frequencies and across all three axes of rotation. In thoroughly considering methodological and other differences between the current and previous studies, we conclude yaw rotation thresholds do not differ from those in roll or pitch.
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Affiliation(s)
- Aaron R Allred
- Smead Department of Aerospace Engineering Sciences, University of Colorado-Boulder, Boulder, CO, United States.
| | - Torin K Clark
- Smead Department of Aerospace Engineering Sciences, University of Colorado-Boulder, Boulder, CO, United States
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17
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Noisy galvanic vestibular stimulation improves vestibular perception in bilateral vestibulopathy. J Neurol 2023; 270:938-943. [PMID: 36324034 PMCID: PMC9886588 DOI: 10.1007/s00415-022-11438-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2022] [Revised: 10/17/2022] [Accepted: 10/18/2022] [Indexed: 11/06/2022]
Abstract
BACKGROUND Patients with bilateral vestibulopathy (BVP) suffer from impaired vestibular motion perception that is linked to deficits in spatial memory and navigation. OBJECTIVE To examine the potential therapeutic effect of imperceptible noisy galvanic vestibular stimulation (nGVS) on impaired vestibular perceptual performance in BVP. METHODS In 11 patients with BVP (mean age: 54.0 ± 8.3 years, 7 females), we initially determined the nGVS intensity that optimally stabilizes balance during a static posturographic assessment. Subsequently, effects of optimal nGVS vs. sham stimulation on vestibular motion perception were examined in randomized order. Vestibular perceptual performance was determined as direction recognition thresholds for head-centered roll tilt motion on a 6DOF motion platform in the absence of any visual or auditory motion cues. RESULTS For each patient, an nGVS intensity that optimally stabilized static balance compared to sham stimulation could be identified (mean 0.36 ± 0.16 mA). nGVS at optimal intensity resulted in lowered vestibular perceptual thresholds (0.94 ± 0.30 deg/s) compared to sham stimulation (1.67 ± 1.11 deg/s; p = 0.040). nGVS-induced improvements in vestibular perception were observed in 8 of 11 patients (73%) and were greater in patients with poorer perceptual performance during sham stimulation (R = - 0.791; p = 0.007). CONCLUSIONS nGVS is effective in improving impaired vestibular motion perception in patients with BVP, in particular in those patients with poor baseline perceptual performance. Imperceptible vestibular noise stimulation might thus offer a non-invasive approach to target BVP-related impairments in spatial memory, orientation, and navigation.
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18
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Keriven Serpollet D, Hartnagel D, James Y, Buffat S, Vayatis N, Bargiotas I, Vidal P. Tilt perception is different in the pitch and roll planes in human. Physiol Rep 2023; 11:e15374. [PMID: 36780905 PMCID: PMC9925277 DOI: 10.14814/phy2.15374] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2021] [Revised: 04/21/2022] [Accepted: 05/27/2022] [Indexed: 02/15/2023] Open
Abstract
Neurophysiological tests probing the vestibulo-ocular, colic and spinal pathways are the gold standard to evaluate the vestibular system in clinics. In contrast, vestibular perception is rarely tested despite its potential usefulness in professional training and for the longitudinal follow-up of professionals dealing with complex man-machine interfaces, such as aircraft pilots. This is explored here using a helicopter flight simulator to probe the vestibular perception of pilots. The vestibular perception of nine professional helicopter pilots was tested using a full flight helicopter simulator. The cabin was tilted six times in roll and six times in pitch (-15°, -10°, -5°, 5°, 10° and 15°) while the pilots had no visual cue. The velocities of the outbound displacement of the cabin were kept below the threshold of the semicircular canal perception. After the completion of each movement, the pilots were asked to put the cabin back in the horizontal plane (still without visual cues). The order of the 12 trials was randomized with two additional control trials where the cabin stayed in the horizontal plane but rotated in yaw (-10° and +10°). Pilots were significantly more precise in roll (average error in roll: 1.15 ± 0.67°) than in pitch (average error in pitch: 2.89 ± 1.06°) (Wilcoxon signed-rank test: p < 0.01). However, we did not find a significant difference either between left and right roll tilts (p = 0.51) or between forward and backward pitch tilts (p = 0.59). Furthermore, we found that the accuracies were significantly biased with respect to the initial tilt. The greater the initial tilt was, the less precise the pilots were, although maintaining the direction of the tilt, meaning that the error can be expressed as a vestibular error gain in the ability to perceive the modification in the orientation. This significant result was found in both roll (Friedman test: p < 0.01) and pitch (p < 0.001). However, the pitch trend error was more prominent (gain = 0.77 vs gain = 0.93) than roll. This study is a first step in the determination of the perceptive-motor profile of pilots, which could be of major use for their training and their longitudinal follow-up. A similar protocol may also be useful in clinics to monitor the aging process of the otolith system with a simplified testing device.
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Affiliation(s)
- Dimitri Keriven Serpollet
- Training & Simulation, Thales AVS France SASOsnyFrance
- Centre Borelli, Université de Paris, ENS Paris‐Saclay, CNRS, SSAParisFrance
| | - David Hartnagel
- Département Neurosciences et Sciences CognitivesInstitut de Recherche Biomédicale des ArméesBrétigny‐sur‐OrgeFrance
| | - Yannick James
- Training & Simulation, Thales AVS France SASOsnyFrance
| | - Stéphane Buffat
- Laboratoire d'Accidentologie de Biomécanique et du comportement des conducteursGIE Renault‐PSA GroupesNanterreFrance
| | - Nicolas Vayatis
- Centre Borelli, Université de Paris, ENS Paris‐Saclay, CNRS, SSAParisFrance
| | - Ioannis Bargiotas
- Centre Borelli, Université de Paris, ENS Paris‐Saclay, CNRS, SSAParisFrance
| | - Pierre‐Paul Vidal
- Centre Borelli, Université de Paris, ENS Paris‐Saclay, CNRS, SSAParisFrance
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19
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Sinnott C, Hausamann PA, MacNeilage PR. Natural statistics of human head orientation constrain models of vestibular processing. RESEARCH SQUARE 2023:rs.3.rs-2412413. [PMID: 36711500 PMCID: PMC9882651 DOI: 10.21203/rs.3.rs-2412413/v1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
Head orientation relative to gravity determines how gravity-dependent environmental structure is sampled by the visual system, as well as how gravity itself is sampled by the vestibular system. Therefore, both visual and vestibular sensory processing should be shaped by the statistics of head orientation relative to gravity. Here we report the statistics of human head orientation during unconstrained natural activities in humans for the first time, and we explore implications for models of vestibular processing. We find that the distribution of head pitch is more variable than head roll and that the head pitch distribution is asymmetrical with an over-representation of downward head pitch, consistent with ground-looking behavior. We further show that pitch and roll distributions can be used as empirical priors in a Bayesian framework to explain previously measured biases in perception of both roll and pitch. We also analyze the dynamics of human head orientation to better understand how gravitational and inertial acceleration are processed by the vestibular system. Gravitational acceleration dominates at low frequencies and inertial acceleration dominates at higher frequencies. The change in relative power of gravitational and inertial components as a function of frequency places empirical constraints on dynamic models of vestibular processing. We conclude with a discussion of methodological considerations and scientific and applied domains that will benefit from continued measurement and analysis of natural head movements moving forward.
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Affiliation(s)
- Christian Sinnott
- University of Nevada, Department of Psychology, Reno, 89557, United States of America,
| | - Peter A. Hausamann
- Technical University of Munich, Department of Electrical and Computer Engineering, Munich, 80333, Germany
| | - Paul R. MacNeilage
- University of Nevada, Department of Psychology, Reno, 89557, United States of America
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20
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Wagner AR, Kobel MJ, Tajino J, Merfeld DM. Improving self-motion perception and balance through roll tilt perceptual training. J Neurophysiol 2022; 128:619-633. [PMID: 35894439 PMCID: PMC9448335 DOI: 10.1152/jn.00092.2022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2022] [Revised: 07/18/2022] [Accepted: 07/23/2022] [Indexed: 11/22/2022] Open
Abstract
The present study aimed to determine if a vestibular perceptual learning intervention could improve roll tilt self-motion perception and balance performance. Two intervention groups (n = 10 each) performed 1,300 trials of roll tilt at either 0.5 Hz (2 s/motion) or 0.2 Hz (5 s/motion) distributed over 5 days; each intervention group was provided feedback (correct/incorrect) after each trial. Roll tilt perceptual thresholds, measured using 0.2-, 0.5-, and 1-Hz stimuli, as well as quiet stance postural sway, were measured on day 1 and day 6 of the study. The control group (n = 10) who performed no perceptual training, showed stable 0.2-Hz (+1.48%, P > 0.99), 0.5-Hz (-4.0%, P > 0.99), and 1-Hz (-17.48%, P = 0.20) roll tilt thresholds. The 0.2-Hz training group demonstrated significant improvements in both 0.2-Hz (-23.77%, P = 0.003) and 0.5-Hz (-22.2%, P = 0.03) thresholds. The 0.5-Hz training group showed a significant improvement in 0.2-Hz thresholds (-19.13%, P = 0.029), but not 0.5-Hz thresholds (-17.68%, P = 0.052). Neither training group improved significantly at the untrained 1-Hz frequency (P > 0.05). In addition to improvements in perceptual precision, the 0.5-Hz training group showed a decrease in sway when measured during "eyes open, on foam" (dz = 0.57, P = 0.032) and "eyes closed, on foam" (dz = 2.05, P < 0.001) quiet stance balance tasks. These initial data suggest that roll tilt perception can be improved with less than 5 h of training and that vestibular perceptual training may contribute to a reduction in subclinical postural instability.NEW & NOTEWORTHY Roll tilt vestibular perceptual thresholds, an assay of vestibular noise, were recently found to correlate with postural sway. We therefore hypothesized that roll tilt perceptual training would yield improvements in both perceptual precision and balance. Our data show that roll tilt perceptual thresholds and quiet stance postural sway can be significantly improved after less than 5 h of roll tilt perceptual training, supporting the hypothesis that vestibular noise contributes to increased postural sway.
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Affiliation(s)
- Andrew R Wagner
- Department of Otolaryngology-Head & Neck Surgery, Ohio State University Wexner Medical Center, Columbus, Ohio
- School of Health and Rehabilitation Sciences, Ohio State University, Columbus, Ohio
| | - Megan J Kobel
- Department of Otolaryngology-Head & Neck Surgery, Ohio State University Wexner Medical Center, Columbus, Ohio
- Department of Speech and Hearing Science, Ohio State University, Columbus, Ohio
| | - Junichi Tajino
- Department of Otolaryngology-Head & Neck Surgery, Ohio State University Wexner Medical Center, Columbus, Ohio
| | - Daniel M Merfeld
- Department of Otolaryngology-Head & Neck Surgery, Ohio State University Wexner Medical Center, Columbus, Ohio
- School of Health and Rehabilitation Sciences, Ohio State University, Columbus, Ohio
- Department of Speech and Hearing Science, Ohio State University, Columbus, Ohio
- Department of Biomedical Engineering, Ohio State University, Columbus, Ohio
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21
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Stavropoulos A, Lakshminarasimhan KJ, Laurens J, Pitkow X, Angelaki D. Influence of sensory modality and control dynamics on human path integration. eLife 2022; 11:63405. [PMID: 35179488 PMCID: PMC8856658 DOI: 10.7554/elife.63405] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2020] [Accepted: 12/11/2021] [Indexed: 12/02/2022] Open
Abstract
Path integration is a sensorimotor computation that can be used to infer latent dynamical states by integrating self-motion cues. We studied the influence of sensory observation (visual/vestibular) and latent control dynamics (velocity/acceleration) on human path integration using a novel motion-cueing algorithm. Sensory modality and control dynamics were both varied randomly across trials, as participants controlled a joystick to steer to a memorized target location in virtual reality. Visual and vestibular steering cues allowed comparable accuracies only when participants controlled their acceleration, suggesting that vestibular signals, on their own, fail to support accurate path integration in the absence of sustained acceleration. Nevertheless, performance in all conditions reflected a failure to fully adapt to changes in the underlying control dynamics, a result that was well explained by a bias in the dynamics estimation. This work demonstrates how an incorrect internal model of control dynamics affects navigation in volatile environments in spite of continuous sensory feedback.
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Affiliation(s)
- Akis Stavropoulos
- Center for Neural Science, New York University, New York, United States
| | | | - Jean Laurens
- Ernst Strüngmann Institute for Neuroscience, Frankfurt, Germany
| | - Xaq Pitkow
- Department of Electrical and Computer Engineering, Rice University, Houston, United States.,Department of Neuroscience, Baylor College of Medicine, Houston, United States.,Center for Neuroscience and Artificial Intelligence, Baylor College of Medicine, Houston, United States
| | - Dora Angelaki
- Center for Neural Science, New York University, New York, United States.,Department of Neuroscience, Baylor College of Medicine, Houston, United States.,Tandon School of Engineering, New York University, New York, United States
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22
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Wagner AR, Kobel MJ, Merfeld DM. Impacts of Rotation Axis and Frequency on Vestibular Perceptual Thresholds. Multisens Res 2022; 35:259-287. [DOI: 10.1163/22134808-bja10069] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2021] [Accepted: 12/15/2021] [Indexed: 11/19/2022]
Abstract
Abstract
In an effort to characterize the factors influencing the perception of self-motion rotational cues, vestibular self-motion perceptual thresholds were measured in 14 subjects for rotations in the roll and pitch planes, as well as in the planes aligned with the anatomic orientation of the vertical semicircular canals (i.e., left anterior, right posterior; LARP, and right anterior, left posterior; RALP). To determine the multisensory influence of concurrent otolith cues, within each plane of motion, thresholds were measured at four discrete frequencies for rotations about earth-horizontal (i.e., tilts; EH) and earth-vertical axes (i.e., head positioned in the plane of the rotation; EV). We found that the perception of rotations, stimulating primarily the vertical canals, was consistent with the behavior of a high-pass filter for all planes of motion, with velocity thresholds increasing at lower frequencies of rotation. In contrast, tilt (i.e, EH rotation) velocity thresholds, stimulating both the canals and otoliths (i.e., multisensory integration), decreased at lower frequencies and were significantly lower than earth-vertical rotation thresholds at each frequency below 2 Hz. These data suggest that multisensory integration of otolithic gravity cues with semicircular canal rotation cues enhances perceptual precision for tilt motions at frequencies below 2 Hz. We also showed that rotation thresholds, at least partially, were dependent on the orientation of the rotation plane relative to the anatomical alignment of the vertical canals. Collectively these data provide the first comprehensive report of how frequency and axis of rotation influence perception of rotational self-motion cues stimulating the vertical canals.
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Affiliation(s)
- Andrew R. Wagner
- Otolaryngology — Head & Neck Surgery, Ohio State University Wexner Medical Center, 915 Olentangy River Rd, Columbus, OH 43212, USA
- Health and Rehabilitation Sciences, Ohio State University, Columbus, OH 43210, USA
| | - Megan J. Kobel
- Otolaryngology — Head & Neck Surgery, Ohio State University Wexner Medical Center, 915 Olentangy River Rd, Columbus, OH 43212, USA
- Speech and Hearing Science, Ohio State University, Columbus, OH 43210, USA
| | - Daniel M. Merfeld
- Otolaryngology — Head & Neck Surgery, Ohio State University Wexner Medical Center, 915 Olentangy River Rd, Columbus, OH 43212, USA
- Health and Rehabilitation Sciences, Ohio State University, Columbus, OH 43210, USA
- Speech and Hearing Science, Ohio State University, Columbus, OH 43210, USA
- Biomedical Engineering, Ohio State University, Columbus, OH 43210, USA
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23
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Wagner AR, Kobel MJ, Merfeld DM. Impact of Canal-Otolith Integration on Postural Control. Front Integr Neurosci 2022; 15:773008. [PMID: 34970126 PMCID: PMC8713561 DOI: 10.3389/fnint.2021.773008] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2021] [Accepted: 11/23/2021] [Indexed: 11/13/2022] Open
Abstract
Roll tilt vestibular perceptual thresholds, an assay of vestibular noise, have recently been shown to be associated with suboptimal balance performance in healthy older adults. However, despite the strength of this correlation, the use of a categorical (i.e., pass/fail) balance assessment limits insight into the impacts of vestibular noise on postural sway. As a result, an explanation for this correlation has yet to be determined. We hypothesized that the correlation between roll tilt vestibular thresholds and postural control reflects a shared influence of sensory noise. To address this hypothesis, we measured roll tilt perceptual thresholds at multiple frequencies (0.2 Hz, 0.5 Hz, 1 Hz) and compared each threshold to quantitative measures of quiet stance postural control in 33 healthy young adults (mean = 24.9 years, SD = 3.67). Our data showed a significant linear association between 0.5 Hz roll tilt thresholds and the root mean square distance (RMSD) of the center of pressure in the mediolateral (ML; β = 5.31, p = 0.002, 95% CI = 2.1-8.5) but not anteroposterior (AP; β = 5.13, p = 0.016, 95% CI = 1.03-9.23) direction (Bonferroni corrected α of 0.006). In contrast, vestibular thresholds measured at 0.2 Hz and 1 Hz did not show a significant correlation with ML or AP RMSD. In a multivariable regression model, controlling for both 0.2 Hz and 1 Hz thresholds, the significant effect of 0.5 Hz roll tilt thresholds persisted (β = 5.44, p = 0.029, CI = 0.60-10.28), suggesting that the effect cannot be explained by elements shared by vestibular thresholds measured at the three frequencies. These data suggest that vestibular noise is significantly associated with the temporospatial control of quiet stance in the mediolateral plane when visual and proprioceptive cues are degraded (i.e., eyes closed, standing on foam). Furthermore, the selective association of quiet-stance sway with 0.5 Hz roll tilt thresholds, but not thresholds measured at lower (0.2 Hz) or higher (1.0 Hz) frequencies, may reflect the influence of noise that results from the temporal integration of noisy canal and otolith cues.
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Affiliation(s)
- Andrew R Wagner
- Department of Otolaryngology-Head & Neck Surgery, Ohio State University Wexner Medical Center, Columbus, OH, United States.,School of Health and Rehabilitation Sciences, Ohio State University, Columbus, OH, United States
| | - Megan J Kobel
- Department of Otolaryngology-Head & Neck Surgery, Ohio State University Wexner Medical Center, Columbus, OH, United States.,Department of Speech and Hearing Science, Ohio State University, Columbus, OH, United States
| | - Daniel M Merfeld
- Department of Otolaryngology-Head & Neck Surgery, Ohio State University Wexner Medical Center, Columbus, OH, United States.,School of Health and Rehabilitation Sciences, Ohio State University, Columbus, OH, United States.,Department of Speech and Hearing Science, Ohio State University, Columbus, OH, United States.,Department of Biomedical Engineering, Ohio State University, Columbus, OH, United States
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24
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Putman EJ, Galvan-Garza RC, Clark TK. The Effect of Noisy Galvanic Vestibular Stimulation on Learning of Functional Mobility and Manual Control Nulling Sensorimotor Tasks. Front Hum Neurosci 2021; 15:756674. [PMID: 34803637 PMCID: PMC8595260 DOI: 10.3389/fnhum.2021.756674] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2021] [Accepted: 10/11/2021] [Indexed: 11/13/2022] Open
Abstract
Galvanic vestibular stimulation (GVS) is a non-invasive method of electrically stimulating the vestibular system. We investigated whether the application of GVS can alter the learning of new functional mobility and manual control tasks and whether learning can be retained following GVS application. In a between-subjects experiment design, 36 healthy subjects performed repeated trials, capturing the learning of either (a) a functional mobility task, navigating an obstacle course on a compliant surface with degraded visual cues or (b) a manual control task, using a joystick to null self-roll tilt against a pseudo-random disturbance while seated in the dark. In the “learning” phase of trials, bilateral, bipolar GVS was applied continuously. The GVS waveform also differed between subjects in each task group: (1) white noisy galvanic vestibular stimulation (nGVS) at 0.3 mA (2) high-level random GVS at 0.7 mA (selected from pilot testing as destabilizing, but not painful), or (3) with the absence of stimulation (i.e., sham). Following the “learning” trials, all subjects were blindly transitioned to sham GVS, upon which they immediately completed another series of trials to assess any aftereffects. In the functional mobility task, we found nGVS significantly improved task learning (p = 0.03, mean learning metric 171% more than the sham group). Further, improvements in learning the functional mobility task with nGVS were retained, even once the GVS application was stopped. The benefits in learning with nGVS were not observed in the manual control task. High level GVS tended to inhibit learning in both tasks, but not significantly so. Even once the high-level stimulation was stopped, the impaired performance remained. Improvements in learning with nGVS may be due to increased information throughput resulting from stochastic resonance. The benefit of nGVS for functional mobility, but not manual control nulling, may be due to the multisensory (e.g., visual and proprioceptive), strategic, motor coordination, or spatial awareness aspects of the former task. Learning improvements with nGVS have the potential to benefit individuals who perform functional mobility tasks, such as astronauts, firefighters, high performance athletes, and soldiers.
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Affiliation(s)
- Esther J Putman
- Ann and H.J. Smead Aerospace Engineering Sciences, University of Colorado, Boulder, Boulder, CO, United States
| | | | - Torin K Clark
- Ann and H.J. Smead Aerospace Engineering Sciences, University of Colorado, Boulder, Boulder, CO, United States
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Bretl KN, Clark TK. Predicting individual acclimation to the cross-coupled illusion for artificial gravity. J Vestib Res 2021; 32:305-316. [PMID: 34806642 DOI: 10.3233/ves-210019] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
BACKGROUND The cross-coupled (CC) illusion and associated motion sickness limits the tolerability of fast-spin-rate centrifugation for artificial gravity implementation. Humans acclimate to the CC illusion through repeated exposure; however, substantial inter-individual differences in acclimation exist, which remain poorly understood. To address this, we investigated several potential predictors of individual acclimation to the CC illusion. METHODS Eleven subjects were exposed to the CC illusion for up to 50 25-minute acclimation sessions. The metric of acclimation rate was calculated as the slope of each subject's linear increase in spin rate across sessions. As potential predictors of acclimation rate, we gathered age, gender, demographics, and activity history, and measured subjects' vestibular perceptual thresholds in the yaw, pitch, and roll rotation axes. RESULTS We found a significant, negative correlation (p = 0.025) between subjects' acclimation rate and roll threshold, suggesting lower thresholds yielded faster acclimation. Additionally, a leave-one-out cross-validation analysis indicated that roll thresholds are predictive of acclimation rates. Correlations between acclimation and other measures were not found but were difficult to assess within our sample. CONCLUSIONS The ability to predict individual differences in CC illusion acclimation rate using roll thresholds is critical to optimizing acclimation training, improving the feasibility of fast-rotation, short-radius centrifugation for artificial gravity.
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Affiliation(s)
- Kathrine N Bretl
- University of Colorado Boulder, 3775 Discovery Drive, Boulder, CO, United States
| | - Torin K Clark
- University of Colorado Boulder, 3775 Discovery Drive, Boulder, CO, United States
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26
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Kravets VG, Dixon JB, Ahmed NR, Clark TK. COMPASS: Computations for Orientation and Motion Perception in Altered Sensorimotor States. Front Neural Circuits 2021; 15:757817. [PMID: 34720889 PMCID: PMC8553968 DOI: 10.3389/fncir.2021.757817] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2021] [Accepted: 09/23/2021] [Indexed: 11/30/2022] Open
Abstract
Reliable perception of self-motion and orientation requires the central nervous system (CNS) to adapt to changing environments, stimuli, and sensory organ function. The proposed computations required of neural systems for this adaptation process remain conceptual, limiting our understanding and ability to quantitatively predict adaptation and mitigate any resulting impairment prior to completing adaptation. Here, we have implemented a computational model of the internal calculations involved in the orientation perception system’s adaptation to changes in the magnitude of gravity. In summary, we propose that the CNS considers parallel, alternative hypotheses of the parameter of interest (in this case, the CNS’s internal estimate of the magnitude of gravity) and uses the associated sensory conflict signals (i.e., difference between sensory measurements and the expectation of them) to sequentially update the posterior probability of each hypothesis using Bayes rule. Over time, an updated central estimate of the internal magnitude of gravity emerges from the posterior probability distribution, which is then used to process sensory information and produce perceptions of self-motion and orientation. We have implemented these hypotheses in a computational model and performed various simulations to demonstrate quantitative model predictions of adaptation of the orientation perception system to changes in the magnitude of gravity, similar to those experienced by astronauts during space exploration missions. These model predictions serve as quantitative hypotheses to inspire future experimental assessments.
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Affiliation(s)
- Victoria G Kravets
- Bioastronautics Laboratory, Ann and H.J. Smead Department of Aerospace Engineering Sciences, University of Colorado Boulder, Boulder, CO, United States
| | - Jordan B Dixon
- Bioastronautics Laboratory, Ann and H.J. Smead Department of Aerospace Engineering Sciences, University of Colorado Boulder, Boulder, CO, United States
| | - Nisar R Ahmed
- COHRINT Laboratory, Ann and H.J. Smead Department of Aerospace Engineering Sciences, University of Colorado Boulder, Boulder, CO, United States
| | - Torin K Clark
- Bioastronautics Laboratory, Ann and H.J. Smead Department of Aerospace Engineering Sciences, University of Colorado Boulder, Boulder, CO, United States
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27
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Diaz-Artiles A, Karmali F. Vestibular Precision at the Level of Perception, Eye Movements, Posture, and Neurons. Neuroscience 2021; 468:282-320. [PMID: 34087393 PMCID: PMC9188304 DOI: 10.1016/j.neuroscience.2021.05.028] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2020] [Revised: 05/20/2021] [Accepted: 05/24/2021] [Indexed: 11/18/2022]
Abstract
Precision and accuracy are two fundamental properties of any system, including the nervous system. Reduced precision (i.e., imprecision) results from the presence of neural noise at each level of sensory, motor, and perceptual processing. This review has three objectives: (1) to show the importance of studying vestibular precision, and specifically that studying accuracy without studying precision ignores fundamental aspects of the vestibular system; (2) to synthesize key hypotheses about precision in vestibular perception, the vestibulo-ocular reflex, posture, and neurons; and (3) to show that groups of studies that are thoughts to be distinct (e.g., perceptual thresholds, subjective visual vertical variability, neuronal variability) are actually "two sides of the same coin" - because the methods used allow results to be related to the standard deviation of a Gaussian distribution describing the underlying neural noise. Vestibular precision varies with age, stimulus amplitude, stimulus frequency, body orientation, motion direction, pathology, medication, and electrical/mechanical vestibular stimulation, but does not vary with sex. The brain optimizes precision during integration of vestibular cues with visual, auditory, and/or somatosensory cues. Since a common concern with precision metrics is time required for testing, we describe approaches to optimize data collection and provide evidence that fatigue and session effects are minimal. Finally, we summarize how precision is an individual trait that is correlated with clinical outcomes in patients as well as with performance in functional tasks like balance. These findings highlight the importance of studying vestibular precision and accuracy, and that knowledge gaps remain.
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Affiliation(s)
- Ana Diaz-Artiles
- Bioastronautics and Human Performance Laboratory, Department of Aerospace Engineering, Department of Health and Kinesiology, Texas A&M University, College Station, TX 77843-3141, USA. https://bhp.engr.tamu.edu
| | - Faisal Karmali
- Jenks Vestibular Physiology Laboratory, Massachusetts Eye and Ear Infirmary, Boston, MA, USA; Department of Otolaryngology - Head and Neck Surgery, Harvard Medical School, Boston MA, USA.
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Statistical approaches to identifying lapses in psychometric response data. Psychon Bull Rev 2021; 28:1433-1457. [PMID: 33825094 DOI: 10.3758/s13423-021-01876-2] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/02/2021] [Indexed: 11/08/2022]
Abstract
Psychometric curve fits relate physical stimuli to an observer's performance. In experiments an observer may "lapse" and respond with a random guess, which may negatively impact (e.g., bias) the psychometric fit parameters. A lapse-rate model has been popularized by Wichmann and Hill, which reduces the impact of lapses on other estimated parameters by adding a parameter to model the lapse rate. Since lapses are discrete events, we developed a discrete lapse theory and tested a "lapse identification" algorithm to identify individual outlier trials (i.e., potential lapses) based upon an approximate statistical criterion and discard these trials. Specifically, we focused on stimuli sampled using an adaptive staircase for a one-interval, direction-recognition task (i.e., psychometric function ranging from 0 to 1 and the spread of the curve corresponds to the threshold, which is often a parameter of interest for many fitted psychometric functions). Through simulations, we found that as the lapse rate increased the threshold became substantially overestimated, consistent with earlier analyses. While the lapse-rate model reduced the overestimation of threshold with many lapses, with lower lapse rates it yielded substantial threshold underestimation, though less so when fitting many (e.g., 1,000) trials. In comparison, the lapse-identification algorithm yielded accurate threshold estimates across a wide range of lapse rates (from 0 to 5%), which is critical since the lapse rate is seldom known. We further demonstrate the performance of the lapse-identification algorithm to be suitable for a variety of experimental conditions and conclude with some considerations of its use. In particular, we suggest using the lapse-identification algorithm unless the experiment has many trials (e.g., >500) or if somehow the lapse rate is known to be high (e.g., ≥5%), for which the lapse-rate model approaches remain preferred.
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An Implanted Vestibular Prosthesis Improves Spatial Orientation in Animals with Severe Vestibular Damage. J Neurosci 2021; 41:3879-3888. [PMID: 33731447 DOI: 10.1523/jneurosci.2204-20.2021] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2020] [Revised: 02/10/2021] [Accepted: 03/08/2021] [Indexed: 11/21/2022] Open
Abstract
Gravity is a pervasive environmental stimulus, and accurate graviception is required for optimal spatial orientation and postural stability. The primary graviceptors are the vestibular organs, which include angular velocity (semicircular canals) and linear acceleration (otolith organs) sensors. Graviception is degraded in patients with vestibular damage, resulting in spatial misperception and imbalance. Since minimal therapy is available for these patients, substantial effort has focused on developing a vestibular prosthesis or vestibular implant (VI) that reproduces information normally provided by the canals (since reproducing otolith function is very challenging technically). Prior studies demonstrated that angular eye velocity responses could be driven by canal VI-mediated angular head velocity information, but it remains unknown whether a canal VI could improve spatial perception and posture since these behaviors require accurate estimates of angular head position in space relative to gravity. Here, we tested the hypothesis that a canal VI that transduces angular head velocity and provides this information to the brain via motion-modulated electrical stimulation of canal afferent nerves could improve the perception of angular head position relative to gravity in monkeys with severe vestibular damage. Using a subjective visual vertical task, we found that normal female monkeys accurately sensed the orientation of the head relative to gravity during dynamic tilts, that this ability was degraded following bilateral vestibular damage, and improved when the canal VI was used. These results demonstrate that a canal VI can improve graviception in vestibulopathic animals, suggesting that it could reduce the disabling perceptual and postural deficits experienced by patients with severe vestibular damage.SIGNIFICANCE STATEMENT Patients with vestibular damage experience impaired vision, spatial perception, and balance, symptoms that could potentially respond to a vestibular implant (VI). Anatomic features facilitate semicircular canal (angular velocity) prosthetics but inhibit approaches with the otolith (linear acceleration) organs, and canal VIs that sense angular head velocity can generate compensatory eye velocity responses in vestibulopathic subjects. Can the brain use canal VI head velocity information to improve estimates of head orientation (e.g., head position relative to gravity), which is a prerequisite for accurate spatial perception and posture? Here we show that a canal VI can improve the perception of head orientation in vestibulopathic monkeys, results that are highly significant because they suggest that VIs mimicking canal function can improve spatial orientation and balance in vestibulopathic patients.
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30
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Kobel MJ, Wagner AR, Merfeld DM, Mattingly JK. Vestibular Thresholds: A Review of Advances and Challenges in Clinical Applications. Front Neurol 2021; 12:643634. [PMID: 33679594 PMCID: PMC7933227 DOI: 10.3389/fneur.2021.643634] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2020] [Accepted: 02/01/2021] [Indexed: 12/15/2022] Open
Abstract
Vestibular disorders pose a substantial burden on the healthcare system due to a high prevalence and the severity of symptoms. Currently, a large portion of patients experiencing vestibular symptoms receive an ambiguous diagnosis or one that is based solely on history, unconfirmed by any objective measures. As patients primarily experience perceptual symptoms (e.g., dizziness), recent studies have investigated the use of vestibular perceptual thresholds, a quantitative measure of vestibular perception, in clinical populations. This review provides an overview of vestibular perceptual thresholds and the current literature assessing use in clinical populations as a potential diagnostic tool. Patients with peripheral and central vestibular pathologies, including bilateral vestibulopathy and vestibular migraine, show characteristic changes in vestibular thresholds. Vestibular perceptual thresholds have also been found to detect subtle, sub-clinical declines in vestibular function in asymptomatic older adults, suggesting a potential use of vestibular thresholds to augment or complement existing diagnostic methods in multiple populations. Vestibular thresholds are a reliable, sensitive, and specific assay of vestibular precision, however, continued research is needed to better understand the possible applications and limitations, especially with regard to the diagnosis of vestibular disorders.
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Affiliation(s)
- Megan J Kobel
- Department of Otolaryngology - Head and Neck Surgery, The Ohio State University Wexner Medical Center, Columbus, OH, United States.,Department of Speech and Hearing Science, The Ohio State University, Columbus, OH, United States
| | - Andrew R Wagner
- Department of Otolaryngology - Head and Neck Surgery, The Ohio State University Wexner Medical Center, Columbus, OH, United States.,Department of Health and Rehabilitation Sciences, The Ohio State University, Columbus, OH, United States
| | - Daniel M Merfeld
- Department of Otolaryngology - Head and Neck Surgery, The Ohio State University Wexner Medical Center, Columbus, OH, United States
| | - Jameson K Mattingly
- Department of Otolaryngology - Head and Neck Surgery, The Ohio State University Wexner Medical Center, Columbus, OH, United States
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31
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Wagner AR, Akinsola O, Chaudhari AMW, Bigelow KE, Merfeld DM. Measuring Vestibular Contributions to Age-Related Balance Impairment: A Review. Front Neurol 2021; 12:635305. [PMID: 33633678 PMCID: PMC7900546 DOI: 10.3389/fneur.2021.635305] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2020] [Accepted: 01/18/2021] [Indexed: 12/16/2022] Open
Abstract
Aging is associated with progressive declines in both the vestibular and human balance systems. While vestibular lesions certainly contribute to imbalance, the specific contributions of age-related vestibular declines to age-related balance impairment is poorly understood. This gap in knowledge results from the absence of a standardized method for measuring age-related changes to the vestibular balance pathways. The purpose of this manuscript is to provide an overview of the existing body of literature as it pertains to the methods currently used to infer vestibular contributions to age-related imbalance.
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Affiliation(s)
- Andrew R. Wagner
- School of Health and Rehabilitation Science, The Ohio State University, Columbus, OH, United States
- Department of Otolaryngology—Head and Neck Surgery, The Ohio State University, Columbus, OH, United States
| | - Olaoluwa Akinsola
- Department of Mechanical and Aerospace Engineering, The Ohio State University, Columbus, OH, United States
| | - Ajit M. W. Chaudhari
- School of Health and Rehabilitation Science, The Ohio State University, Columbus, OH, United States
- Department of Mechanical and Aerospace Engineering, The Ohio State University, Columbus, OH, United States
| | - Kimberly E. Bigelow
- Department of Mechanical and Aerospace Engineering, University of Dayton, Dayton, OH, United States
| | - Daniel M. Merfeld
- School of Health and Rehabilitation Science, The Ohio State University, Columbus, OH, United States
- Department of Otolaryngology—Head and Neck Surgery, The Ohio State University, Columbus, OH, United States
- Department of Biomedical Engineering, The Ohio State University, Columbus, OH, United States
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32
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Karmali F, Goodworth AD, Valko Y, Leeder T, Peterka RJ, Merfeld DM. The role of vestibular cues in postural sway. J Neurophysiol 2021; 125:672-686. [PMID: 33502934 DOI: 10.1152/jn.00168.2020] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
Abstract
Controlling posture requires continuous sensory feedback about body motion and orientation, including from the vestibular organs. Little is known about the role of tilt vs. translation vs. rotation vestibular cues. We examined whether intersubject differences in vestibular function were correlated with intersubject differences in postural control. Vestibular function was assayed using vestibular direction-recognition perceptual thresholds, which determine the smallest motion that can be reliably perceived by a subject seated on a motorized platform in the dark. In study A, we measured thresholds for lateral translation, vertical translation, yaw rotation, and head-centered roll tilts. In study B, we measured thresholds for roll, pitch, and left anterior-right posterior and right anterior-left posterior tilts. Center-of-pressure (CoP) sway was measured in sensory organization tests (study A) and Romberg tests (study B). We found a strong positive relationship between CoP sway and lateral translation thresholds but not CoP sway and other thresholds. This finding suggests that the vestibular encoding of lateral translation may contribute substantially to balance control. Since thresholds assay sensory noise, our results support the hypothesis that vestibular noise contributes to spontaneous postural sway. Specifically, we found that lateral translation thresholds explained more of the variation in postural sway in postural test conditions with altered proprioceptive cues (vs. a solid surface), consistent with postural sway being more dependent on vestibular noise when the vestibular contribution to balance is higher. These results have potential implications for vestibular implants, balance prostheses, and physical therapy exercises.NEW & NOTEWORTHY Vestibular feedback is important for postural control, but little is known about the role of tilt cues vs. translation cues vs. rotation cues. We studied healthy human subjects with no known vestibular pathology or symptoms. Our findings showed that vestibular encoding of lateral translation correlated with medial-lateral postural sway, consistent with lateral translation cues contributing to balance control. This adds support to the hypothesis that vestibular noise contributes to spontaneous postural sway.
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Affiliation(s)
- Faisal Karmali
- Department of Otolaryngology-Head and Neck Surgery, Harvard Medical School, Boston, Massachusetts.,Jenks Vestibular Physiology Laboratory, Massachusetts Eye and Ear, Boston, Massachusetts
| | - Adam D Goodworth
- Kinesiology Department, Westmont College, Santa Barbara, California
| | - Yulia Valko
- Departments of Ophthalmology and Neurology, University Hospital Zurich, University of Zurich, Switzerland
| | - Tania Leeder
- Jenks Vestibular Physiology Laboratory, Massachusetts Eye and Ear, Boston, Massachusetts
| | - Robert J Peterka
- Department of Neurology, Oregon Health and Science University, Portland, Oregon.,National Center for Rehabilitative Auditory Research, Veterans Affairs Portland Health Care System, Portland, Oregon
| | - Daniel M Merfeld
- Department of Otolaryngology - Head and Neck Surgery, The Ohio State University, Columbus, Ohio
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Roll tilt self-motion direction discrimination training: First evidence for perceptual learning. Atten Percept Psychophys 2020; 82:1987-1999. [PMID: 31898068 PMCID: PMC7297830 DOI: 10.3758/s13414-019-01967-2] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Perceptual learning, the ability to improve the sensitivity of sensory perception through training, has been shown to exist in all sensory systems but the vestibular system. A previous study found no improvement of passive self-motion thresholds in the dark after intense direction discrimination training of either yaw rotations (stimulating semicircular canals) or y-translation (stimulating otoliths). The goal of the present study was to investigate whether perceptual learning of self-motion in the dark would occur when there is a simultaneous otolith and semicircular canal input, as is the case with roll tilt motion stimuli. Blindfolded subjects (n = 10) trained on a direction discrimination task with 0.2-Hz roll tilt motion stimuli (9 h of training, 1,800 trials). Before and after training, motion thresholds were measured in the dark for the trained motion and for three transfer conditions. We found that roll tilt sensitivity in the 0.2-Hz roll tilt condition was increased (i.e., thresholds decreased) after training but not for controls who were not exposed to training. This is the first demonstration of perceptual learning of passive self-motion direction discrimination in the dark. The results have potential therapeutic relevance as 0.2-Hz roll thresholds have been associated with poor performance on a clinical balance test that has been linked to more than a fivefold increase in falls.
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Wada Y, Yamanaka T, Kitahara T, Kurata J. Effect of head roll-tilt on the subjective visual vertical in healthy participants: Towards better clinical measurement of gravity perception. Laryngoscope Investig Otolaryngol 2020; 5:941-949. [PMID: 33134543 PMCID: PMC7585259 DOI: 10.1002/lio2.461] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2020] [Revised: 07/27/2020] [Accepted: 09/12/2020] [Indexed: 01/25/2023] Open
Abstract
OBJECTIVE Gravity perception is an essential function for spatial orientation and postural stability; however, its assessment is not easy. We evaluated the head-tilt perception gain (HTPG, that is, mean perceptual gain [perceived/actual tilt angle] during left or right head roll-tilt conditions) and head-upright subjective visual vertical (SVV) using a simple method developed by us to investigate the characteristics of gravity perception in healthy participants. METHODS We measured the SVV and head roll-tilt angle during head roll-tilt within ±30° of vertical in the sitting and standing positions while the participant maintained an upright trunk (sitting, 434 participants; standing, 263 participants). We evaluated the head-upright SVV, HTPG, and laterality of the HTPG. RESULTS We determined the reference ranges of the absolute head-upright SVV (<2.5°), HTPG (0.80-1.25), and HTPG laterality (<10%) for the sitting position. The head-upright SVV and HTPG laterality were not influenced by sex or age. However, the HTPG was significantly greater in women than in men and in middle-aged (30-64 years) and elderly (65-88 years) participants than in young participants (18-29 years). The HTPG, but not the head-upright SVV or HTPG laterality, was significantly higher in the standing vs sitting position. CONCLUSION The HTPG is a novel parameter of gravity perception involving functions of the peripheral otolith and neck somatosensory systems to the central nervous system. The HTPG in healthy participants is influenced by age and sex in the sitting position and immediately increases after standing to reinforce the righting reflex for unstable posture, which was not seen in the head-upright SVV, previously considered the only parameter. LEVEL OF EVIDENCE 4.
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Affiliation(s)
- Yoshiro Wada
- Department of Otolaryngology, Head and Neck SurgeryNara Medical UniversityNaraJapan
- Wada ENT ClinicOsakaJapan
| | - Toshiaki Yamanaka
- Department of Otolaryngology, Head and Neck SurgeryNara Medical UniversityNaraJapan
| | - Tadashi Kitahara
- Department of Otolaryngology, Head and Neck SurgeryNara Medical UniversityNaraJapan
| | - Junichi Kurata
- Department of Mechanical Systems EngineeringKansai UniversityOsakaJapan
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Human vestibular perceptual thresholds for pitch tilt are slightly worse than for roll tilt across a range of frequencies. Exp Brain Res 2020; 238:1499-1509. [DOI: 10.1007/s00221-020-05830-x] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2020] [Accepted: 05/08/2020] [Indexed: 01/18/2023]
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36
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Laurens J, Angelaki DE. Simple spike dynamics of Purkinje cells in the macaque vestibulo-cerebellum during passive whole-body self-motion. Proc Natl Acad Sci U S A 2020; 117:3232-3238. [PMID: 31988119 PMCID: PMC7022220 DOI: 10.1073/pnas.1915873117] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Theories of cerebellar functions posit that the cerebellum implements internal models for online correction of motor actions and sensory estimation. As an example of such computations, an internal model resolves a sensory ambiguity where the peripheral otolith organs in the inner ear sense both head tilts and translations. Here we exploit the response dynamics of two functionally coupled Purkinje cell types in the vestibular part of the caudal vermis (lobules IX and X) to understand their role in this computation. We find that one population encodes tilt velocity, whereas the other, translation-selective, population encodes linear acceleration. We predict that an intermediate neuronal type should temporally integrate the output of tilt-selective cells into a tilt position signal.
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Affiliation(s)
- Jean Laurens
- Department of Neuroscience, Baylor College of Medicine, Houston, TX 77056
| | - Dora E Angelaki
- Department of Neuroscience, Baylor College of Medicine, Houston, TX 77056;
- Center for Neural Science, New York University, New York, NY 10003
- Tandon School of Engineering, New York University, New York, NY 10003
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37
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Shayman CS, Peterka RJ, Gallun FJ, Oh Y, Chang NYN, Hullar TE. Frequency-dependent integration of auditory and vestibular cues for self-motion perception. J Neurophysiol 2020; 123:936-944. [PMID: 31940239 DOI: 10.1152/jn.00307.2019] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Recent evidence has shown that auditory information may be used to improve postural stability, spatial orientation, navigation, and gait, suggesting an auditory component of self-motion perception. To determine how auditory and other sensory cues integrate for self-motion perception, we measured motion perception during yaw rotations of the body and the auditory environment. Psychophysical thresholds in humans were measured over a range of frequencies (0.1-1.0 Hz) during self-rotation without spatial auditory stimuli, rotation of a sound source around a stationary listener, and self-rotation in the presence of an earth-fixed sound source. Unisensory perceptual thresholds and the combined multisensory thresholds were found to be frequency dependent. Auditory thresholds were better at lower frequencies, and vestibular thresholds were better at higher frequencies. Expressed in terms of peak angular velocity, multisensory vestibular and auditory thresholds ranged from 0.39°/s at 0.1 Hz to 0.95°/s at 1.0 Hz and were significantly better over low frequencies than either the auditory-only (0.54°/s to 2.42°/s at 0.1 and 1.0 Hz, respectively) or vestibular-only (2.00°/s to 0.75°/s at 0.1 and 1.0 Hz, respectively) unisensory conditions. Monaurally presented auditory cues were less effective than binaural cues in lowering multisensory thresholds. Frequency-independent thresholds were derived, assuming that vestibular thresholds depended on a weighted combination of velocity and acceleration cues, whereas auditory thresholds depended on displacement and velocity cues. These results elucidate fundamental mechanisms for the contribution of audition to balance and help explain previous findings, indicating its significance in tasks requiring self-orientation.NEW & NOTEWORTHY Auditory information can be integrated with visual, proprioceptive, and vestibular signals to improve balance, orientation, and gait, but this process is poorly understood. Here, we show that auditory cues significantly improve sensitivity to self-motion perception below 0.5 Hz, whereas vestibular cues contribute more at higher frequencies. Motion thresholds are determined by a weighted combination of displacement, velocity, and acceleration information. These findings may help understand and treat imbalance, particularly in people with sensory deficits.
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Affiliation(s)
- Corey S Shayman
- Department of Otolaryngology-Head and Neck Surgery, Oregon Health and Science University, Portland, Oregon.,School of Medicine, University of Utah, Salt Lake City, Utah
| | - Robert J Peterka
- Department of Neurology, Oregon Health and Science University, Portland, Oregon.,National Center for Rehabilitative Auditory Research-VA Portland Health Care System, Portland, Oregon
| | - Frederick J Gallun
- National Center for Rehabilitative Auditory Research-VA Portland Health Care System, Portland, Oregon.,Oregon Hearing Research Center, Department of Otolaryngology-Head and Neck Surgery, Oregon Health and Science University, Portland, Oregon
| | - Yonghee Oh
- Department of Speech, Language, and Hearing Sciences, University of Florida, Gainesville, Florida
| | - Nai-Yuan N Chang
- Department of Preventive and Restorative Dental Sciences-Division of Bioengineering and Biomaterials, University of California, San Francisco, San Francisco, California
| | - Timothy E Hullar
- Department of Otolaryngology-Head and Neck Surgery, Oregon Health and Science University, Portland, Oregon.,Department of Neurology, Oregon Health and Science University, Portland, Oregon.,National Center for Rehabilitative Auditory Research-VA Portland Health Care System, Portland, Oregon
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38
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Self-motion perception is sensitized in vestibular migraine: pathophysiologic and clinical implications. Sci Rep 2019; 9:14323. [PMID: 31586151 PMCID: PMC6778132 DOI: 10.1038/s41598-019-50803-y] [Citation(s) in RCA: 47] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2019] [Accepted: 09/16/2019] [Indexed: 12/30/2022] Open
Abstract
Vestibular migraine (VM) is the most common cause of spontaneous vertigo but remains poorly understood. We investigated the hypothesis that central vestibular pathways are sensitized in VM by measuring self-motion perceptual thresholds in patients and control subjects and by characterizing the vestibulo-ocular reflex (VOR) and vestibular and headache symptom severity. VM patients were abnormally sensitive to roll tilt, which co-modulates semicircular canal and otolith organ activity, but not to motions that activate the canals or otolith organs in isolation, implying sensitization of canal-otolith integration. When tilt thresholds were considered together with vestibular symptom severity or VOR dynamics, VM patients segregated into two clusters. Thresholds in one cluster correlated positively with symptoms and with the VOR time constant; thresholds in the second cluster were uniformly low and independent of symptoms and the time constant. The VM threshold abnormality showed a frequency-dependence that paralleled the brain stem velocity storage mechanism. These results support a pathogenic model where vestibular symptoms emanate from the vestibular nuclei, which are sensitized by migraine-related brainstem regions and simultaneously suppressed by inhibitory feedback from the cerebellar nodulus and uvula, the site of canal-otolith integration. This conceptual framework elucidates VM pathophysiology and could potentially facilitate its diagnosis and treatment.
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39
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Cullen KE. Vestibular processing during natural self-motion: implications for perception and action. Nat Rev Neurosci 2019; 20:346-363. [PMID: 30914780 PMCID: PMC6611162 DOI: 10.1038/s41583-019-0153-1] [Citation(s) in RCA: 116] [Impact Index Per Article: 23.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
How the brain computes accurate estimates of our self-motion relative to the world and our orientation relative to gravity in order to ensure accurate perception and motor control is a fundamental neuroscientific question. Recent experiments have revealed that the vestibular system encodes this information during everyday activities using pathway-specific neural representations. Furthermore, new findings have established that vestibular signals are selectively combined with extravestibular information at the earliest stages of central vestibular processing in a manner that depends on the current behavioural goal. These findings have important implications for our understanding of the brain mechanisms that ensure accurate perception and behaviour during everyday activities and for our understanding of disorders of vestibular processing.
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Affiliation(s)
- Kathleen E Cullen
- Department of Biomedical Engineering, Johns Hopkins University, Baltimore, MD, USA.
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40
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Clark TK, Newman MC, Karmali F, Oman CM, Merfeld DM. Mathematical models for dynamic, multisensory spatial orientation perception. PROGRESS IN BRAIN RESEARCH 2019; 248:65-90. [PMID: 31239146 DOI: 10.1016/bs.pbr.2019.04.014] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Mathematical models have been proposed for how the brain interprets sensory information to produce estimates of self-orientation and self-motion. This process, spatial orientation perception, requires dynamically integrating multiple sensory modalities, including visual, vestibular, and somatosensory cues. Here, we review the progress in mathematical modeling of spatial orientation perception, focusing on dynamic multisensory models, and the experimental paradigms in which they have been validated. These models are primarily "black box" or "as if" models for how the brain processes spatial orientation cues. Yet, they have been effective scientifically, in making quantitative hypotheses that can be empirically assessed, and operationally, in investigating aircraft pilot disorientation, for example. The primary family of models considered, the observer model, implements estimation theory approaches, hypothesizing that internal models (i.e., neural systems replicating the behavior/dynamics of physical systems) are used to produce expected sensory measurements. Expected signals are then compared to actual sensory afference, yielding sensory conflict, which is weighted to drive central perceptions of gravity, angular velocity, and translation. This approach effectively predicts a wide range of experimental scenarios using a small set of fixed free parameters. We conclude with limitations and applications of existing mathematical models and important areas of future work.
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Affiliation(s)
- Torin K Clark
- Smead Aerospace Engineering Sciences, University of Colorado-Boulder, Boulder, CO, United States.
| | - Michael C Newman
- Environmental Tectonics Corporation, Southampton, PA, United States
| | - Faisal Karmali
- Jenks Vestibular Physiology Laboratory, Massachusetts Eye and Ear Infirmary, Boston, MA, United States; Otolaryngology, Harvard Medical School, Boston, MA, United States
| | - Charles M Oman
- Human Systems Laboratory, Massachusetts Institute of Technology, Cambridge, MA, United States
| | - Daniel M Merfeld
- Otolaryngology-Head and Neck Surgery, The Ohio State University, Columbus, OH, United States; Naval Aerospace Medical Research Lab (NAMRL), Naval Medical Research Unit-Dayton (NAMRUD), Dayton, OH, United States
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41
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Alberts BBGT, Selen LPJ, Medendorp WP. Age-related reweighting of visual and vestibular cues for vertical perception. J Neurophysiol 2019; 121:1279-1288. [PMID: 30699005 DOI: 10.1152/jn.00481.2018] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
As we age, the acuity of our sensory organs declines, which may affect our lifestyle. Sensory deterioration in the vestibular system is typically bilateral and gradual, and could lead to problems with balance and spatial orientation. To compensate for the sensory deterioration, it has been suggested that the brain reweights the sensory information sources according to their relative noise characteristics. For rehabilitation and training programs, it is important to understand the consequences of this reweighting, preferably at the individual subject level. We psychometrically examined the age-dependent reweighting of visual and vestibular cues used in spatial orientation in a group of 32 subjects (age range: 19-76 yr). We asked subjects to indicate the orientation of a line (clockwise or counterclockwise relative to the gravitational vertical) presented within an oriented square visual frame when seated upright or with their head tilted 30° relative to the body. Results show that subjects' vertical perception is biased by the orientation of the visual frame. Both the magnitude of this bias and response variability become larger with increasing age. Deducing the underlying sensory noise characteristics, using Bayesian inference, suggests an age-dependent reweighting of sensory information, with an increasing weight of the visual contextual information. Further scrutiny of the model suggests that this shift in sensory weights is the result of an increase in the noise of the vestibular signal. Our approach quantifies how noise properties of visual and vestibular systems change over the life span, which helps to understand the aging process at the neurocomputational level. NEW & NOTEWORTHY Perception of visual vertical involves a weighted fusion of visual and vestibular tilt cues. Using a Bayesian approach and experimental psychophysics, we quantify how this fusion process changes with age. We show that, with age, the vestibular information is down-weighted whereas the visual weight is increased. This shift in sensory reweighting is primarily due to an age-related increase of the noise of vestibular signals.
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Affiliation(s)
- Bart B G T Alberts
- Radboud University , Donders Institute for Brain, Cognition and Behaviour, Nijmegen , The Netherlands
| | - Luc P J Selen
- Radboud University , Donders Institute for Brain, Cognition and Behaviour, Nijmegen , The Netherlands
| | - W Pieter Medendorp
- Radboud University , Donders Institute for Brain, Cognition and Behaviour, Nijmegen , The Netherlands
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42
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The velocity storage time constant: Balancing between accuracy and precision. PROGRESS IN BRAIN RESEARCH 2019; 248:269-276. [DOI: 10.1016/bs.pbr.2019.04.038] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/12/2023]
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43
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Galvan-Garza RC, Clark TK, Sherwood D, Diaz-Artiles A, Rosenberg M, Natapoff A, Karmali F, Oman CM, Young LR. Human perception of whole body roll-tilt orientation in a hypogravity analog: underestimation and adaptation. J Neurophysiol 2018; 120:3110-3121. [PMID: 30332330 DOI: 10.1152/jn.00140.2018] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Overestimation of roll tilt in hypergravity ("G-excess" illusion) has been demonstrated, but corresponding sustained hypogravic conditions are impossible to create in ground laboratories. In this article we describe the first systematic experimental evidence that in a hypogravity analog, humans underestimate roll tilt. We studied perception of self-roll tilt in nine subjects, who were supine while spun on a centrifuge to create a hypogravity analog. By varying the centrifuge rotation rate, we modulated the centripetal acceleration (GC) at the subject's head location (0.5 or 1 GC) along the body axis. We measured orientation perception using a subjective visual vertical task in which subjects aligned an illuminated bar with their perceived centripetal acceleration direction during tilts (±11.5-28.5°). As hypothesized, based on the reduced utricular otolith shearing, subjects initially underestimated roll tilts in the 0.5 GC condition compared with the 1 GC condition (mean perceptual gain change = -0.27, P = 0.01). When visual feedback was given after each trial in 0.5 GC, subjects' perceptual gain increased in approximately exponential fashion over time (time constant = 16 tilts or 13 min), and after 45 min, the perceptual gain was not significantly different from the 1 GC baseline (mean gain difference between 1 GC initial and 0.5 GC final = 0.16, P = 0.3). Thus humans modified their interpretation of sensory cues to more correctly report orientation during this hypogravity analog. Quantifying the acute orientation perceptual learning in such an altered gravity environment may have implications for human space exploration on the moon or Mars. NEW & NOTEWORTHY Humans systematically overestimate roll tilt in hypergravity. However, human perception of orientation in hypogravity has not been quantified across a range of tilt angles. Using a centrifuge to create a hypogravity centripetal acceleration environment, we found initial underestimation of roll tilt. Providing static visual feedback, perceptual learning reduced underestimation during the hypogravity analog. These altered gravity orientation perceptual errors and adaptation may have implications for astronauts.
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Affiliation(s)
- Raquel C Galvan-Garza
- Jenks Vestibular Physiology Laboratory, Massachusetts Eye and Ear Infirmary, Boston, Massachusetts.,Man-Vehicle Laboratory, Massachusetts Institute of Technology , Cambridge, Massachusetts
| | - Torin K Clark
- Jenks Vestibular Physiology Laboratory, Massachusetts Eye and Ear Infirmary, Boston, Massachusetts.,Otology and Laryngology, Harvard Medical School , Boston, Massachusetts.,Man-Vehicle Laboratory, Massachusetts Institute of Technology , Cambridge, Massachusetts.,Smead Aerospace Engineering Sciences, University of Colorado , Boulder, Colorado
| | - David Sherwood
- Jenks Vestibular Physiology Laboratory, Massachusetts Eye and Ear Infirmary, Boston, Massachusetts.,Man-Vehicle Laboratory, Massachusetts Institute of Technology , Cambridge, Massachusetts
| | - Ana Diaz-Artiles
- Jenks Vestibular Physiology Laboratory, Massachusetts Eye and Ear Infirmary, Boston, Massachusetts.,Man-Vehicle Laboratory, Massachusetts Institute of Technology , Cambridge, Massachusetts.,Sibley School of Mechanical and Aerospace Engineering, Cornell University , Ithaca, New York.,Aerospace Engineering, Texas A&M University , College Station, Texas
| | - Marissa Rosenberg
- Jenks Vestibular Physiology Laboratory, Massachusetts Eye and Ear Infirmary, Boston, Massachusetts.,KBRwyle Science, Technology, and Engineering Group , Houston, Texas
| | - Alan Natapoff
- Man-Vehicle Laboratory, Massachusetts Institute of Technology , Cambridge, Massachusetts
| | - Faisal Karmali
- Jenks Vestibular Physiology Laboratory, Massachusetts Eye and Ear Infirmary, Boston, Massachusetts.,Otology and Laryngology, Harvard Medical School , Boston, Massachusetts.,Man-Vehicle Laboratory, Massachusetts Institute of Technology , Cambridge, Massachusetts
| | - Charles M Oman
- Man-Vehicle Laboratory, Massachusetts Institute of Technology , Cambridge, Massachusetts
| | - Laurence R Young
- Man-Vehicle Laboratory, Massachusetts Institute of Technology , Cambridge, Massachusetts
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44
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Rosenberg MJ, Galvan-Garza RC, Clark TK, Sherwood DP, Young LR, Karmali F. Human manual control precision depends on vestibular sensory precision and gravitational magnitude. J Neurophysiol 2018; 120:3187-3197. [PMID: 30379610 DOI: 10.1152/jn.00565.2018] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
Precise motion control is critical to human survival on Earth and in space. Motion sensation is inherently imprecise, and the functional implications of this imprecision are not well understood. We studied a "vestibular" manual control task in which subjects attempted to keep themselves upright with a rotational hand controller (i.e., joystick) to null out pseudorandom, roll-tilt motion disturbances of their chair in the dark. Our first objective was to study the relationship between intersubject differences in manual control performance and sensory precision, determined by measuring vestibular perceptual thresholds. Our second objective was to examine the influence of altered gravity on manual control performance. Subjects performed the manual control task while supine during short-radius centrifugation, with roll tilts occurring relative to centripetal accelerations of 0.5, 1.0, and 1.33 GC (1 GC = 9.81 m/s2). Roll-tilt vestibular precision was quantified with roll-tilt vestibular direction-recognition perceptual thresholds, the minimum movement that one can reliably distinguish as leftward vs. rightward. A significant intersubject correlation was found between manual control performance (defined as the standard deviation of chair tilt) and thresholds, consistent with sensory imprecision negatively affecting functional precision. Furthermore, compared with 1.0 GC manual control was more precise in 1.33 GC (-18.3%, P = 0.005) and less precise in 0.5 GC (+39.6%, P < 0.001). The decrement in manual control performance observed in 0.5 GC and in subjects with high thresholds suggests potential risk factors for piloting and locomotion, both on Earth and during human exploration missions to the moon (0.16 G) and Mars (0.38 G). NEW & NOTEWORTHY The functional implications of imprecise motion sensation are not well understood. We found a significant correlation between subjects' vestibular perceptual thresholds and performance in a manual control task (using a joystick to keep their chair upright), consistent with sensory imprecision negatively affecting functional precision. Furthermore, using an altered-gravity centrifuge configuration, we found that manual control precision was improved in "hypergravity" and degraded in "hypogravity." These results have potential relevance for postural control, aviation, and spaceflight.
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Affiliation(s)
- Marissa J Rosenberg
- Jenks Vestibular Physiology Lab, Massachusetts Eye and Ear Infirmary, Boston, Massachusetts.,KBRwyle Science, Technology and Engineering, NASA Johnson Space Center , Houston, Texas.,Center for Space Medicine, Baylor College of Medicine , Houston, Texas
| | - Raquel C Galvan-Garza
- Jenks Vestibular Physiology Lab, Massachusetts Eye and Ear Infirmary, Boston, Massachusetts.,Massachusetts Institute of Technology , Cambridge, Massachusetts
| | - Torin K Clark
- Jenks Vestibular Physiology Lab, Massachusetts Eye and Ear Infirmary, Boston, Massachusetts.,Massachusetts Institute of Technology , Cambridge, Massachusetts.,Department of Otolaryngology, Harvard Medical School , Boston, Massachusetts.,University of Colorado at Boulder , Boulder, Colorado
| | - David P Sherwood
- Massachusetts Institute of Technology , Cambridge, Massachusetts
| | - Laurence R Young
- Massachusetts Institute of Technology , Cambridge, Massachusetts
| | - Faisal Karmali
- Jenks Vestibular Physiology Lab, Massachusetts Eye and Ear Infirmary, Boston, Massachusetts.,Massachusetts Institute of Technology , Cambridge, Massachusetts.,Department of Otolaryngology, Harvard Medical School , Boston, Massachusetts
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45
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Variability in the Vestibulo-Ocular Reflex and Vestibular Perception. Neuroscience 2018; 393:350-365. [PMID: 30189227 DOI: 10.1016/j.neuroscience.2018.08.025] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2017] [Revised: 08/23/2018] [Accepted: 08/24/2018] [Indexed: 11/24/2022]
Abstract
The vestibular system enables humans to estimate self-motion, stabilize gaze and maintain posture, but these behaviors are impacted by neural noise at all levels of processing (e.g., sensory, central, motor). Despite its essential importance, the behavioral impact of noise in human vestibular pathways is not completely understood. Here, we characterize the vestibular imprecision that results from neural noise by measuring trial-to-trial vestibulo-ocular reflex (VOR) variability and perceptual just-noticeable differences (JNDs) in the same human subjects as a function of stimulus intensity. We used head-centered yaw rotations about an Earth-vertical axis over a broad range of motion velocities (0-65°/s for VOR variability and 3-90°/s peak velocity for JNDs). We found that VOR variability increased from approximately 0.6°/s at a chair velocity of 1°/s to approximately 3°/s at 65°/s; it exhibited a stimulus-independent range below roughly 1°/s. Perceptual imprecision ("sigma") increased from 0.76°/s at 3°/s to 4.7°/s at 90°/s. Using stimuli that manipulated the relationship between velocity, displacement and acceleration, we found that velocity was the salient cue for VOR variability for our motion stimuli. VOR and perceptual imprecision both increased with stimulus intensity and were broadly similar over a range of stimulus velocities, consistent with a common noise source that affects motor and perceptual pathways. This contrasts with differing perceptual and motor stimulus-dependent imprecision in visual studies. Either stimulus-dependent noise or non-linear signal processing could explain our results, but we argue that afferent non-linearities alone are unlikely to be the source of the observed behavioral stimulus-dependent imprecision.
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46
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Galvan-Garza R, Clark T, Mulavara A, Oman C. Exhibition of stochastic resonance in vestibular tilt motion perception. Brain Stimul 2018; 11:716-722. [DOI: 10.1016/j.brs.2018.03.017] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2017] [Revised: 03/25/2018] [Accepted: 03/30/2018] [Indexed: 10/17/2022] Open
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47
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Keywan A, Wuehr M, Pradhan C, Jahn K. Noisy Galvanic Stimulation Improves Roll-Tilt Vestibular Perception in Healthy Subjects. Front Neurol 2018; 9:83. [PMID: 29545766 PMCID: PMC5837962 DOI: 10.3389/fneur.2018.00083] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2017] [Accepted: 02/06/2018] [Indexed: 11/13/2022] Open
Abstract
It has recently been demonstrated that noisy galvanic vestibular stimulation (nGVS) delivered as imperceptible white noise can improve balance control via the induction of stochastic resonance. However, it is unclear whether these balance improvements are accompanied by simultaneous enhancement to vestibular motion perception. In this study, 15 healthy subjects performed 8 quiet-stance tasks on foam with eyes closed at 8 different nGVS amplitudes ranging from 0 mA (baseline) to 0.5 mA. The nGVS amplitude that improved balance performance most compared to baseline was assigned as the optimal nGVS amplitude. Optimal nGVS amplitudes could be determined for 13 out of 15 subjects, who were included in the subsequent experimental procedures. The effect of nGVS delivered at the determined optimal intensity on vestibular perceptual thresholds was examined using direction-recognition tasks on a motion platform, testing roll rotations at 0.2, 0.5, and 1.0 Hz, both with active and sham nGVS stimulations. nGVS significantly reduced direction-recognition thresholds compared to the sham condition at 0.5 and 1.0 Hz, while no significant effect of nGVS was found at 0.2 Hz. Interestingly, no correlation was found between nGVS-induced improvements in balance control and vestibular motion perception at 0.5 and 1 Hz, which may suggest different mechanisms by which nGVS affects both modalities. For the first time, we show that nGVS can enhance roll vestibular motion perception. The outcomes of this study are likely to be relevant for the potential therapeutic use of nGVS in patients with balance problems.
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Affiliation(s)
- Aram Keywan
- German Center for Vertigo and Balance Disorders, Munich University Hospital, Munich, Germany
| | - Max Wuehr
- German Center for Vertigo and Balance Disorders, Munich University Hospital, Munich, Germany
| | - Cauchy Pradhan
- German Center for Vertigo and Balance Disorders, Munich University Hospital, Munich, Germany
| | - Klaus Jahn
- German Center for Vertigo and Balance Disorders, Munich University Hospital, Munich, Germany.,Department of Neurology, Schön Klinik Bad Aibling, Bad Aibling, Germany
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48
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Goodworth AD, Tetreault K, Lanman J, Klidonas T, Kim S, Saavedra S. Sensorimotor control of the trunk in sitting sway referencing. J Neurophysiol 2018; 120:37-52. [PMID: 29488840 DOI: 10.1152/jn.00330.2017] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
We developed a sway-referenced system for sitting to highlight the role of vestibular and visual contributions to trunk control. Motor control was investigated by measuring trunk kinematics in the frontal plane while manipulating visual availability and introducing a concurrent cognitive task. We examined motor learning on three timescales (within the same trial, minutes), within the same test session (1 h), and between sessions (1 wk). Posture sway was analyzed through time-based measures [root mean square (RMS) sway and RMS velocity], frequency-based measures (amplitude spectra), and parameterized feedback modeling. We found that posture differed in both magnitude and frequency distribution during sway referencing compared with quiet sitting. Modeling indicated that sway referencing caused greater uncertainty/noise in sensory feedback and motor outputs. Sway referencing was also associated with lower active stiffness and damping model parameters. The influence of vision and a cognitive task was more apparent during sway referencing compared with quiet sitting. Short-term learning was reflected by reduced RMS velocity in quiet sitting immediately following sway referencing. Longer term learning was evident from one week to the next, with a 23% decrease in RMS sway and 9% decrease in RMS velocity. These changes occurred predominantly during cognitive tests at lower frequencies and were associated with lower sensory noise and higher stiffness and integral gains in the model. With the findings taken together, the sitting sway-referenced test elicited neural changes consistent with optimal integration and sensory reweighting, similar to standing, and should be a valuable tool to closely examine sensorimotor control of the trunk. NEW & NOTEWORTHY We developed the first sway-referenced system for sitting to highlight the role of vestibular and visual contributions to trunk control. A parametric feedback model explained sensorimotor control and motor learning in the task with and between two test sessions. The sitting sway-referenced test elicited neural changes consistent with optimal integration and sensory reweighting, similar to standing, and should be a valuable tool to closely examine sensorimotor control of the trunk.
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Affiliation(s)
| | | | | | | | - Seyoung Kim
- Korea Institute of Machinery & Materials, Daejeon, Republic of Korea
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49
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Bermúdez Rey MC, Clark TK, Merfeld DM. Balance Screening of Vestibular Function in Subjects Aged 4 Years and Older: A Living Laboratory Experience. Front Neurol 2017; 8:631. [PMID: 29234301 PMCID: PMC5712334 DOI: 10.3389/fneur.2017.00631] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2017] [Accepted: 11/13/2017] [Indexed: 01/13/2023] Open
Abstract
To better understand the various individual factors that contribute to balance and the relation to fall risk, we performed the modified Romberg Test of Standing Balance on Firm and Compliant Support, with 1,174 participants between 4 and 83 years of age. This research was conducted in the Living Laboratory® at the Museum of Science, Boston. We specifically focus on balance test condition 4, in which individuals stand on memory foam with eyes closed, and must rely on their vestibular system; therefore, performance in this balance test condition provides a proxy for vestibular function. We looked for balance variations associated with sex, race/ethnicity, health factors, and age. We found that balance test performance was stable between 10 and 39 years of age, with a slight increase in the failure rate for participants 4-9 years of age, suggesting a period of balance development in younger children. For participants 40 years and older, the balance test failure rate increased progressively with age. Diabetes and obesity are the two main health factors we found associated with poor balance, with test condition 4 failure rates of 57 and 19%, respectively. An increase in the odds of having fallen in the last year was associated with a decrease in the time to failure; once individuals dropped below a time to failure of 10 s, there was a significant 5.5-fold increase in the odds of having fallen in the last 12 months. These data alert us to screen for poor vestibular function in individuals 40 years and older or suffering from diabetes, in order to undertake the necessary diagnostic and rehabilitation measures, with a focus on reducing the morbidity and mortality of falls.
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Affiliation(s)
- María Carolina Bermúdez Rey
- Jenks Vestibular Physiology Laboratory, Massachusetts Eye and Ear Infirmary, Boston, MA, United States.,Otolaryngology, Harvard Medical School, Harvard University, Boston, MA, United States
| | - Torin K Clark
- Jenks Vestibular Physiology Laboratory, Massachusetts Eye and Ear Infirmary, Boston, MA, United States.,Otolaryngology, Harvard Medical School, Harvard University, Boston, MA, United States.,Smead Aerospace Engineering Sciences, University of Colorado, Boulder, CO, United States
| | - Daniel M Merfeld
- Jenks Vestibular Physiology Laboratory, Massachusetts Eye and Ear Infirmary, Boston, MA, United States.,Otolaryngology, Harvard Medical School, Harvard University, Boston, MA, United States.,Otolaryngology, The Ohio State University, Columbus, OH, United States
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50
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Karmali F, Whitman GT, Lewis RF. Bayesian optimal adaptation explains age-related human sensorimotor changes. J Neurophysiol 2017; 119:509-520. [PMID: 29118202 DOI: 10.1152/jn.00710.2017] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
The brain uses information from different sensory systems to guide motor behavior, and aging is associated with simultaneous decline in the quality of sensory information provided to the brain and deterioration in motor control. Correlations between age-dependent decline in sensory anatomical structures and behavior have been demonstrated in many sensorimotor systems, and it has recently been suggested that a Bayesian framework could explain these relationships. Here we show that age-dependent changes in a human sensorimotor reflex, the vestibuloocular reflex, are explained by a Bayesian optimal adaptation in the brain occurring in response to death of motion-sensing hair cells. Specifically, we found that the temporal dynamics of the reflex as a function of age emerge from ( r = 0.93, P < 0.001) a Kalman filter model that determines the optimal behavioral output when the sensory signal-to-noise characteristics are degraded by death of the transducers. These findings demonstrate that the aging brain is capable of generating the ideal and statistically optimal behavioral response when provided with deteriorating sensory information. While the Bayesian framework has been shown to be a general neural principle for multimodal sensory integration and dynamic sensory estimation, these findings provide evidence of longitudinal Bayesian processing over the human life span. These results illuminate how the aging brain strives to optimize motor behavior when faced with deterioration in the peripheral and central nervous systems and have implications in the field of vestibular and balance disorders, as they will likely provide guidance for physical therapy and for prosthetic aids that aim to reduce falls in the elderly. NEW & NOTEWORTHY We showed that age-dependent changes in the vestibuloocular reflex are explained by a Bayesian optimal adaptation in the brain that occurs in response to age-dependent sensory anatomical changes. This demonstrates that the brain can longitudinally respond to age-related sensory loss in an ideal and statistically optimal way. This has implications for understanding and treating vestibular disorders caused by aging and provides insight into the structure-function relationship during aging.
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Affiliation(s)
- Faisal Karmali
- Jenks Vestibular Physiology Laboratory, Massachusetts Eye and Ear Infirmary, Boston, Massachusetts.,Department of Otolaryngology, Harvard Medical School , Boston, Massachusetts
| | - Gregory T Whitman
- Department of Otolaryngology, Harvard Medical School , Boston, Massachusetts.,Massachusetts Eye and Ear Infirmary, Boston, Massachusetts
| | - Richard F Lewis
- Jenks Vestibular Physiology Laboratory, Massachusetts Eye and Ear Infirmary, Boston, Massachusetts.,Department of Otolaryngology, Harvard Medical School , Boston, Massachusetts.,Department of Neurology, Harvard Medical School, Boston, Massachusetts
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