1
|
Silva MB, Martinho Fernandes LFR, Caetano E Souza RH, Rosa de Sá AA, Naves ELM. Analysis of ankle muscle activity: A study on static balance with eyes closed and high-heeled shoes. Foot (Edinb) 2024; 60:102100. [PMID: 38810470 DOI: 10.1016/j.foot.2024.102100] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/07/2022] [Revised: 01/31/2023] [Accepted: 05/11/2024] [Indexed: 05/31/2024]
Abstract
BACKGROUND Changes in sensory afferent interfere with the control of postural stability by the central nervous system. Wearing high-heeled shoes is an example of an external disturbance that changes sensory inputs and results in several postural adjustments to control stability. Thus, our purpose is to investigate the influence of high-heeled shoes and visual absence on maintenance of static balance and on ankle muscle activity among young women. Our hypothesis is that the combination of high-heeled shoes with visual absence lead to an increase of postural sway and of levels of activation of the stabilizing ankle muscles. METHODS Nine volunteers remained in an unrestrained erect posture on a force platform for collecting of stabilometric and electromyographic parameters in four bipodal conditions: barefoot with open eyes, barefoot with closed eyes, with high heels and open eyes and with high heels and closed eyes. RESULTS When comparing the experimental condition open and closed eyes with high heels, there were significant differences for all stabilometric variables, except for the confidence ellipse area. Statistical differences were found for the medial gastrocnemius muscle in all comparison pairs with high heels. CONCLUSION The wearing high-heeled shoes showed to be the most influencing disturbance on static balance. Our findings suggest ankle muscle activity is adapted according to changes of the center of pressure sway and the wearing of high heels changes the muscle activation and postural sway.
Collapse
Affiliation(s)
| | | | - Rhaíra Helena Caetano E Souza
- Assistive Technology Laboratory, Faculty of Electrical Engineering, Federal University of Uberlandia, Uberlandia, Brazil
| | - Angela Abreu Rosa de Sá
- Assistive Technology Laboratory, Faculty of Electrical Engineering, Federal University of Uberlandia, Uberlandia, Brazil.
| | - Eduardo Lázaro Martins Naves
- Assistive Technology Laboratory, Faculty of Electrical Engineering, Federal University of Uberlandia, Uberlandia, Brazil
| |
Collapse
|
2
|
Harquel S, Cian C, Torlay L, Cousin E, Barraud PA, Bougerol T, Guerraz M. Modulation of Visually Induced Self-motion Illusions by α Transcranial Electric Stimulation over the Superior Parietal Cortex. J Cogn Neurosci 2024; 36:143-154. [PMID: 37870524 DOI: 10.1162/jocn_a_02074] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2023]
Abstract
The growing popularity of virtual reality systems has led to a renewed interest in understanding the neurophysiological correlates of the illusion of self-motion (vection), a phenomenon that can be both intentionally induced or avoided in such systems, depending on the application. Recent research has highlighted the modulation of α power oscillations over the superior parietal cortex during vection, suggesting the occurrence of inhibitory mechanisms in the sensorimotor and vestibular functional networks to resolve the inherent visuo-vestibular conflict. The present study aims to further explore this relationship and investigate whether neuromodulating these waves could causally affect the quality of vection. In a crossover design, 22 healthy volunteers received high amplitude and focused α-tACS (transcranial alternating current stimulation) over the superior parietal cortex while experiencing visually induced vection triggered by optokinetic stimulation. The tACS was tuned to each participant's individual α peak frequency, with θ-tACS and sham stimulation serving as controls. Overall, participants experienced better quality vection during α-tACS compared with control θ-tACS and sham stimulations, as quantified by the intensity of vection. The observed neuromodulation supports a causal relationship between parietal α oscillations and visually induced self-motion illusions, with their entrainment triggering overinhibition of the conflict within the sensorimotor and vestibular functional networks. These results confirm the potential of noninvasive brain stimulation for modulating visuo-vestibular conflicts, which could help to enhance the sense of presence in virtual reality environments.
Collapse
Affiliation(s)
- Sylvain Harquel
- Université Grenoble-Alpes, Université Savoie Mont Blanc, CNRS, UMR5105, LPNC, Grenoble, France
- Defitech Chair of Clinical Neuroengineering, Center for Neuroprosthetics (CNP) and Brain Mind Institute (BMI), Swiss Federal Institute of Technology Lausanne (EPFL), Campus Biotech, Geneva, Switzerland
| | - Corinne Cian
- Université Grenoble-Alpes, Université Savoie Mont Blanc, CNRS, UMR5105, LPNC, Grenoble, France
- Institut de Recherche Biomédicale des Armées, Brétigny sur Orge, France
| | - Laurent Torlay
- Université Grenoble-Alpes, Université Savoie Mont Blanc, CNRS, UMR5105, LPNC, Grenoble, France
| | - Emilie Cousin
- Université Grenoble-Alpes, Université Savoie Mont Blanc, CNRS, UMR5105, LPNC, Grenoble, France
| | - Pierre-Alain Barraud
- Université Grenoble-Alpes, CNRS, CHU Grenoble-Alpes, Grenoble INP, TIMC-IMAG, Grenoble, France
| | - Thierry Bougerol
- Centre Hospitalier Université Grenoble-Alpes, Pôle Psychiatrie, Grenoble, France
- Université Grenoble-Alpes, Inserm, U1216, Grenoble Institut des Neurosciences, Grenoble, France
| | - Michel Guerraz
- Université Grenoble-Alpes, Université Savoie Mont Blanc, CNRS, UMR5105, LPNC, Grenoble, France
| |
Collapse
|
3
|
Schlienger R, De Giovanni C, Guerraz M, Kavounoudias A. When proprioceptive feedback enhances visual perception of self-body movement: rehabilitation perspectives. Front Hum Neurosci 2023; 17:1144033. [PMID: 37250699 PMCID: PMC10213410 DOI: 10.3389/fnhum.2023.1144033] [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: 01/13/2023] [Accepted: 04/17/2023] [Indexed: 05/31/2023] Open
Abstract
Introduction Rehabilitation approaches take advantage of vision's important role in kinesthesia, using the mirror paradigm as a means to reduce phantom limb pain or to promote recovery from hemiparesis. Notably, it is currently applied to provide a visual reafferentation of the missing limb to relieve amputees' pain. However, the efficiency of this method is still debated, possibly due to the absence of concomitant coherent proprioceptive feedback. We know that combining congruent visuo-proprioceptive signals at the hand level enhances movement perception in healthy people. However, much less is known about lower limbs, for which actions are far less visually controlled in everyday life than upper limbs. Therefore, the present study aimed to explore, with the mirror paradigm, the benefit of combined visuo-proprioceptive feedback from the lower limbs of healthy participants. Methods We compared the movement illusions driven by visual or proprioceptive afferents and tested the extent to which adding proprioceptive input to the visual reflection of the leg improved the resulting movement illusion. To this end, 23 healthy adults were exposed to mirror or proprioceptive stimulation and concomitant visuo-proprioceptive stimulation. In the visual conditions, participants were asked to voluntarily move their left leg in extension and look at its reflection in the mirror. In the proprioceptive conditions, a mechanical vibration was applied to the hamstring muscle of the leg hidden behind the mirror to simulate an extension of the leg, either exclusively or concomitantly, to the visual reflection of the leg in the mirror. Results (i) Visual stimulation evoked leg movement illusions but with a lower velocity than the actual movement reflection on the mirror; (ii) proprioceptive stimulation alone provided more salient illusions than the mirror illusion; and (iii) adding a congruent proprioceptive stimulation improved the saliency, amplitude, and velocity of the illusion. Conclusion The present findings confirm that visuo-proprioceptive integration occurs efficiently when the mirror paradigm is coupled with mechanical vibration at the lower limbs, thus providing promising new perspectives for rehabilitation.
Collapse
Affiliation(s)
- Raphaëlle Schlienger
- Aix-Marseille Université, CNRS, Laboratoire de Neurosciences Cognitives (LNC – UMR 7291), Marseille, France
| | - Claire De Giovanni
- Aix-Marseille Université, CNRS, Laboratoire de Neurosciences Cognitives (LNC – UMR 7291), Marseille, France
| | - Michel Guerraz
- Université Grenoble Alpes, Université Savoie Mont Blanc, CNRS, Laboratoire de Psychologie et NeuroCognition (LPNC – UMR 5105), Grenoble, France
| | - Anne Kavounoudias
- Aix-Marseille Université, CNRS, Laboratoire de Neurosciences Cognitives (LNC – UMR 7291), Marseille, France
| |
Collapse
|
4
|
Fujimoto K, Ashida H. Postural adjustment as a function of scene orientation. J Vis 2022; 22:1. [PMID: 35234839 PMCID: PMC8899856 DOI: 10.1167/jov.22.4.1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Visual orientation plays an important role in postural control, but the specific characteristics of postural response to orientation remain unknown. In this study, we investigated the relationship between postural response and the subjective visual vertical (SVV) as a function of scene orientation. We presented a virtual room including everyday objects through a head-mounted display and measured head tilt around the naso-occipital axis. The room orientation varied from 165° counterclockwise to 180° clockwise around the center of display in 15° increments. In a separate session, we also conducted a rod adjustment task to record the participant's SVV in the tilted room. We applied a weighted vector sum model to head tilt and SVV error and obtained the weight of three visual cues to orientation: frame, horizon, and polarity. We found significant contributions for all visual cues to head tilt and SVV error. For SVV error, frame cues made the largest contribution, whereas polarity contribution made the smallest. For head tilt, there was no clear difference across visual cue types, although the order of contribution was similar to the SVV. These findings suggest that multiple visual cues to orientation are involved in postural control and imply different representations of vertical orientation across postural control and perception.
Collapse
Affiliation(s)
- Kanon Fujimoto
- Department of Psychology, Graduate School of Letters, Kyoto University, Kyoto, Japan.,Japan Society for the Promotion of Science, Tokyo, Japan.,
| | - Hiroshi Ashida
- Department of Psychology, Graduate School of Letters, Kyoto University, Kyoto, Japan.,
| |
Collapse
|
5
|
MicroRNAs in the pathophysiology of Alzheimer's disease and Parkinson's disease: an overview. Mol Neurobiol 2022; 59:1589-1603. [PMID: 35001356 DOI: 10.1007/s12035-022-02727-4] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2021] [Accepted: 12/30/2021] [Indexed: 12/12/2022]
Abstract
Neurodegenerative diseases are characterized by a progressive loss of neurons of the central nervous system (CNS) and serve as a major cause of morbidity, mortality and functional dependence especially among the elderly. Despite extensive research and development efforts, the success rate of clinical pipelines has been very limited. However, microRNAs (miRs) have been proved to be of crucial importance in regulating intracellular pathways for various pathologic conditions including those of a neurodegenerative nature. There is ample evidence of altered levels of various miRs in clinical samples of Alzheimer's disease and Parkinson's disease patients with potentially major clinical implications. In the current review, we aim to summarize the relevant literature on the role of miRs in the pathophysiology of Alzheimer's disease (AD) and Parkinson's disease (PD) as the two globally predominant neurodegenerative conditions.
Collapse
|
6
|
Tixier M, Rousset S, Barraud PA, Cian C. Postural responses to specific types of long-term memory during visually induced roll self-motion. PLoS One 2021; 16:e0261266. [PMID: 34919588 PMCID: PMC8682872 DOI: 10.1371/journal.pone.0261266] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2021] [Accepted: 11/25/2021] [Indexed: 11/29/2022] Open
Abstract
A large body of research has shown that visually induced self-motion (vection) and cognitive processing may interfere with each other. The aim of this study was to assess the interactive effects of a visual motion inducing vection (uniform motion in roll) versus a visual motion without vection (non-uniform motion) and long-term memory processing using the characteristics of standing posture (quiet stance). As the level of interference may be related to the nature of the cognitive tasks used, we examined the effect of visual motion on a memory task which requires a spatial process (episodic recollection) versus a memory task which does not require this process (semantic comparisons). Results confirm data of the literature showing that compensatory postural response in the same direction as background motion. Repeatedly watching visual uniform motion or increasing the cognitive load with a memory task did not decrease postural deviations. Finally, participants were differentially controlling their balance according to the memory task but this difference was significant only in the vection condition and in the plane of background motion. Increased sway regularity (decreased entropy) combined with decreased postural stability (increase variance) during vection for the episodic task would indicate an ineffective postural control. The different interference of episodic and semantic memory on posture during visual motion is consistent with the involvement of spatial processes during episodic memory recollection. It can be suggested that spatial disorientation due to visual roll motion preferentially interferes with spatial cognitive tasks, as spatial tasks can draw on resources expended to control posture.
Collapse
Affiliation(s)
- Maëlle Tixier
- Université Grenoble Alpes, Université Savoie Mont Blanc, CNRS LPNC UMR 5105, Grenoble, France
| | - Stéphane Rousset
- Université Grenoble Alpes, Université Savoie Mont Blanc, CNRS LPNC UMR 5105, Grenoble, France
- * E-mail:
| | - Pierre-Alain Barraud
- Université Grenoble Alpes, CNRS, CHU Grenoble-Alpes, Grenoble INP, TIMC-IMAG, Grenoble, France
| | - Corinne Cian
- Université Grenoble Alpes, Université Savoie Mont Blanc, CNRS LPNC UMR 5105, Grenoble, France
- Institut de Recherche Biomédicale des Armées, Brétigny sur Orge, France
| |
Collapse
|
7
|
Saccadic eye movement performance reduces visual manipulation influence and center of pressure displacements in older fallers. Exp Brain Res 2021; 240:395-406. [PMID: 34741190 DOI: 10.1007/s00221-021-06256-9] [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: 03/25/2021] [Accepted: 10/24/2021] [Indexed: 10/19/2022]
Abstract
This study examined changes in postural control and gaze performance of faller and non-faller older adults under conditions of visual tasks and optical flow manipulations. Fifteen older non-fallers (69.8 years, ± 3.2) and fifteen older fallers (71.1 years, ± 6.4) stood on a force platform inside a moving room wearing an eye tracker. Four tasks were performed: gaze fixation; predictable saccades; unpredictable saccades; and free-viewing. The stimuli appeared at a frequency of 1.1 Hz during conditions of predictable and unpredictable saccades. Sixteen trials were divided into two blocks. In the first block, the room remained stationary. In the second block, the room oscillated, without the participant's awareness, with a 0.6 cm amplitude and 0.2 Hz frequency. Results showed postural sway attenuation in older fallers during the saccadic tasks compared to gaze fixation and free-viewing tasks, in both stationary and moving room conditions. Both groups showed increased center of pressure (CoP) magnitude during the moving room condition and CoP displacements strongly coupled to the room's movement. The influence of the moving room on the postural sway was reduced during the saccadic tasks for both older groups. Older fallers exhibited higher variability compared to older non-fallers. Gaze behavior differences between groups were dependent on the goals of the visual tasks. Therefore, CoP displacements of older adults are reduced during saccadic tasks regardless of their falling history. However, postural and gaze performance of older fallers suggests increased deterioration of postural and oculomotor control which may be used as a predictor of fall risk.
Collapse
|
8
|
Variability of visually-induced center of pressure displacements is reduced while young adults perform unpredictable saccadic eye movements inside a moving room. Neurosci Lett 2021; 764:136276. [PMID: 34597705 DOI: 10.1016/j.neulet.2021.136276] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2020] [Revised: 09/22/2021] [Accepted: 09/26/2021] [Indexed: 11/20/2022]
Abstract
This study investigated the modulation of center of pressure (CoP) displacements of young adults as they performed predictable and unpredictable saccadic eye movements in stationary and moving visual scenarios. We also examined whether the relationship between CoP displacements and visual stimulus, provided by the moving scenario, and gaze control itself, are affected by the demands of the saccadic tasks. Fifteen young adults (20.53 ± 2.1 years old) stood upright on a force plate, inside a moving room, wearing an eye tracker while performing three tasks: gaze fixation (fixating on a target in the center of the screen), predictable task (saccades while following a target which continuously appeared and disappeared on the right and left sides), and unpredictable task (similar to the previous task, but the participants did not know which side the target would appear on). For saccadic tasks, the target appeared at a frequency of 1.1 Hz and with eccentricity of 11.5 degrees of visual angle. Two blocks of six trials were performed: in the first block, the room remained stationary and in the second, it oscillated (0.6 cm amplitude; 0.2 Hz frequency). Mean amplitude of CoP displacements was lower in the saccadic tasks compared to the gaze fixation, in both conditions; and higher in the moving scenario than in the stationary condition. Variability of CoP displacements was lower in the unpredictable saccades than gaze fixation task. Saccade reaction time was longer in the unpredictable than predictable task. We conclude that CoP displacements are reduced to facilitate performance of the saccadic tasks regardless of conditions and task complexity. Furthermore, lower variability suggests modulation of CoP displacements to deal with the increased attentional demands associated with the performance of the unpredictable saccades, indicating the important role of visual task constraints in postural control.
Collapse
|
9
|
Vestibulo-perceptual influences upon the vestibulo-spinal reflex. Exp Brain Res 2021; 239:2141-2149. [PMID: 33969437 PMCID: PMC8282553 DOI: 10.1007/s00221-021-06123-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2020] [Accepted: 04/24/2021] [Indexed: 11/16/2022]
Abstract
The vestibular system facilitates gaze and postural stability via the vestibulo-ocular (VOR) and vestibulo-spinal reflexes, respectively. Cortical and perceptual mechanisms can modulate long-duration VOR responses, but little is known about whether high-order neural phenomena can modulate short-latency vestibulo-spinal responses. Here, we investigate this by assessing click-evoked cervical vestibular myogenic-evoked potentials (VEMPS) during visual roll motion that elicited an illusionary sensation of self-motion (i.e. vection). We observed that during vection, the amplitude of the VEMPs was enhanced when compared to baseline measures. This modulation in VEMP amplitude was positively correlated with the subjective reports of vection strength. That is, those subjects reporting greater subjective vection scores exhibited a greater increase in VEMP amplitude. Control experiments showed that simple arousal (cold-induced discomfort) also increased VEMP amplitude but that, unlike vection, it did not modulate VEMP amplitude linearly. In agreement, small-field visual roll motion that did not induce vection failed to increase VEMP amplitude. Taken together, our results demonstrate that vection can modify the response of vestibulo-collic reflexes. Even short-latency brainstem vestibulo-spinal reflexes are influenced by high-order mechanisms, illustrating the functional importance of perceptual mechanisms in human postural control. As VEMPs are inhibitory responses, we argue that the findings may represent a mechanism whereby high-order CNS mechanisms reduce activity levels in vestibulo-collic reflexes, necessary for instance when voluntary head movements need to be performed.
Collapse
|
10
|
Chowdhury NS, Luu W, Palmisano S, Ujike H, Kim J. Spatial presence depends on 'coupling' between body sway and visual motion presented on head-mounted displays (HMDs). APPLIED ERGONOMICS 2021; 92:103355. [PMID: 33444884 DOI: 10.1016/j.apergo.2021.103355] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/02/2020] [Revised: 12/15/2020] [Accepted: 12/31/2020] [Indexed: 06/12/2023]
Abstract
This study investigated the effects of simulating self-motion via a head-mounted display (HMD) on standing postural sway and spatial presence. Standing HMD users viewed simulated oscillatory self-motion in depth. On a particular trial, this naso-occipital visual oscillation had one of four different amplitudes (either 4, 8, 12 or 16 m peak-to-peak) and one of four different frequencies (either 0.125, 0.25, 0.5 or 1 Hz). We found that simulated high amplitude self-oscillation (approximately 16 m peak-to-peak) at either 0.25 Hz or 0.5 Hz: 1) generated the strongest effects on postural sway; and 2) made participants feel more spatially present in the virtual environment. Our findings provide insight into the parameters of simulated self-motion that generate the strongest postural responses within virtual environments. These postural constraints have valuable implications for improving our understanding of sensory processes underlying the ergonomic experience of virtual environments simulated using HMDs.
Collapse
Affiliation(s)
- Nahian S Chowdhury
- School of Optometry and Vision Science, University of New South Wales, Kensington, New South Wales, Australia.
| | - Wilson Luu
- School of Optometry and Vision Science, University of New South Wales, Kensington, New South Wales, Australia
| | - Stephen Palmisano
- School of Psychology, University of Wollongong, NSW, 2522, Australia
| | - Hiroyasu Ujike
- Human Informatics and Interaction Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba, 305-8566, Japan
| | - Juno Kim
- School of Optometry and Vision Science, University of New South Wales, Kensington, New South Wales, Australia.
| |
Collapse
|
11
|
Matsugi A, Oku K, Mori N. The Effects of Stochastic Galvanic Vestibular Stimulation on Body Sway and Muscle Activity. Front Hum Neurosci 2020; 14:591671. [PMID: 33381017 PMCID: PMC7767904 DOI: 10.3389/fnhum.2020.591671] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2020] [Accepted: 11/18/2020] [Indexed: 12/23/2022] Open
Abstract
Objective: This study aimed to investigate whether galvanic vestibular stimulation with stochastic noise (nGVS) modulates the body sway and muscle activity of the lower limbs, depending on visual and somatosensory information from the foot using rubber-foam. Methods: Seventeen healthy young adults participated in the study. Each subject maintained an upright standing position on a force plate with/without rubber-foam, with their eyes open/closed, to measure the position of their foot center of pressure. Thirty minutes after baseline measurements under four possible conditions (eyes open/closed with/without rubber-foam) performed without nGVS (intensity: 1 mA, duration: 40 s), the stimulation trials (sham-nGVS/real-nGVS) were conducted under the same conditions in random order, which were then repeated a week or more later. The total center of pressure (COP) path length movement (COP-TL) and COP movement velocity in the mediolateral (Vel-ML) and anteroposterior (Vel-AP) directions were recorded for 30 s during nGVS. Furthermore, electromyography activity of the right tibial anterior muscle and soleus muscle was recorded for the same time and analyzed. Results: Three-way analysis of variance and post-hoc multiple comparison revealed a significant increment in COP-related parameters by nGVS, and a significant increment in soleus muscle activity on rubber. There was no significant effect of eye condition on any parameter. Conclusions: During nGVS (1 mA), body sway and muscle activity in the lower limb may be increased depending not on the visual condition, but on the foot somatosensory condition.
Collapse
Affiliation(s)
- Akiyoshi Matsugi
- Faculty of Rehabilitation, Shijonawate Gakuen University, Daitou, Japan
| | - Kosuke Oku
- Department of Rehabilitation, Kawasaki University of Medical Welfare, Kurashiki, Japan
| | - Nobuhiko Mori
- Department of Neuromodulation and Neurosurgery, Graduate School of Medicine, Osaka University, Osaka, Japan.,Department of Neurosurgery, Osaka University Graduate School of Medicine, Osaka, Japan
| |
Collapse
|
12
|
Kucharik M, Kosutzka Z, Pucik J, Hajduk M, Saling M. Processing moving visual scenes during upright stance in elderly patients with mild cognitive impairment. PeerJ 2020; 8:e10363. [PMID: 33240666 PMCID: PMC7680028 DOI: 10.7717/peerj.10363] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2020] [Accepted: 10/24/2020] [Indexed: 11/20/2022] Open
Abstract
Background The ability to maintain balance in an upright stance gradually worsens with age and is even more difficult for patients with cognitive disorders. Cognitive impairment plays a probable role in the worsening of stability. The purpose of this study was to expose subjects with mild cognitive impairment (MCI) and healthy, age-matched controls to moving visual scenes in order to examine their postural adaptation abilities. Methods We observed postural responses to moving visual stimulation while subjects stood on a force platform. The visual disturbance was created by interposing a moving picture in four directions (forward, backward, right, and left). The pre-stimulus (a static scene for 10 s), stimulus (a dynamic visual scene for 20 seconds) and post-stimulus (a static scene for 20 seconds) periods were evaluated. We separately analyzed the total path (TP) of the center of pressure (COP) and the root mean square (RMS) of the COP displacement in all four directions. Results We found differences in the TP of the COP during the post-stimulus period for all stimulus directions except in motion towards the subject (left p = 0.006, right p = 0.004, and away from the subject p = 0.009). Significant RMS differences between groups were also observed during the post-stimulus period in all directions except when directed towards the subject (left p = 0.002, right p = 0.007, and away from the subject p = 0.014). Conclusion Exposing subjects to a moving visual scene induced greater destabilization in MCI subjects compared to healthy elderly controls. Surprisingly, the moving visual scene also induced significant aftereffects in the MCI group. Our findings indicate that the MCI group had diminished adaptation to the dynamic visual scene and recovery. These results suggest that even mild cognitive deficits can impair sensory information integration and alter the sensory re-weighing process.
Collapse
Affiliation(s)
- Martin Kucharik
- Centre of Experimental Medicine, Slovak Academy of Sciences, Bratislava, Slovakia
| | - Zuzana Kosutzka
- Second Department of Neurology, Faculty of Medicine, Comenius University, Bratislava, Slovakia
| | - Jozef Pucik
- Institute of Electronics and Photonics, Faculty of Electrical Engineering and Information Technology, Slovak University of Technology in Bratislava, Bratislava, Slovak Republic
| | - Michal Hajduk
- Department of Psychology, Faculty of Arts, Comenius University, Bratislava, Slovakia.,Department of Psychiatry, Faculty of Medicine, Comenius University, Bratislava, Slovakia.,Center for Psychiatric Disorders Research-Science Park, Comenius University, Bratislava, Slovakia
| | - Marian Saling
- Centre of Experimental Medicine, Slovak Academy of Sciences, Bratislava, Slovakia.,Second Department of Neurology, Faculty of Medicine, Comenius University, Bratislava, Slovakia
| |
Collapse
|
13
|
Fujimoto K, Ashida H. Different Head-Sway Responses to Optic Flow in Sitting and Standing With a Head-Mounted Display. Front Psychol 2020; 11:577305. [PMID: 33123058 PMCID: PMC7573131 DOI: 10.3389/fpsyg.2020.577305] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2020] [Accepted: 09/14/2020] [Indexed: 11/23/2022] Open
Abstract
We investigated postural responses (head displacements) and self-motion perception (vection) to radial and lateral optic flows while sitting and standing by using a head-mounted display. We found that head displacement directions varied across postures. In the standing posture, radial optic flow generally produced the opposed head displacement against the perceived vection direction, consistent with the literature; however, in the sitting posture, the optic flow generally produced the following head displacement in the vection direction. In the standing posture, responses were evident soon after the onset of the optic flow presentation but became less clear in the latter half of a trial. The results, while less clear for lateral flows, were similar for both flow types. Our findings suggest partially distinct processes underlying vection and postural control.
Collapse
Affiliation(s)
- Kanon Fujimoto
- Department of Psychology, Graduate School of Letters, Kyoto University, Kyoto, Japan.,Japan Society for the Promotion of Science, Tokyo, Japan
| | - Hiroshi Ashida
- Department of Psychology, Graduate School of Letters, Kyoto University, Kyoto, Japan
| |
Collapse
|
14
|
Lin SI, Tsai YJ, Lee PY. Balance performance when responding to visual stimuli in patients with Benign Paroxysmal Positional Vertigo (BPPV). J Vestib Res 2020; 30:267-274. [PMID: 32925126 DOI: 10.3233/ves-200709] [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 Patients with Benign Paroxysmal Positional Vertigo (BPPV) often report a sensation of disequilibrium before treatment with the canalith repositioning maneuvers. Apart from vestibular information, visual input also contributes to balance control. How visual stimuli influence balance control in BPPV patients is unclear. OBJECTIVE To investigate the influence of visual stimuli on balance performance in BPPV patients. METHODS Three groups of participants, patients with BPPV, and healthy young and older adults, were instructed to stand under three conditions: 1) eyes open (EO); 2) while watching a static picture via a video display; and 3) while watching a rotating visual scene. Antero-posterior (AP), lateral (ML), and total sway path during standing were analyzed. RESULTS In all conditions, patients with BPPV showed significantly larger AP, ML and total sway path than young, whereas older adults only showed significantly larger AP and total sway path than young adults. During the visual stimuli, all participants exhibited significantly increased AP and total sway while watching a static image and a moving scene as compared with the EO condition. CONCLUSIONS Patients with BPPV have similar balance control to older adults, but poorer balance control than young adults. The reduced lack of standing balance control in the coronal plane of patients with BPPV, might affect balance strategy after external perturbations.
Collapse
Affiliation(s)
- Sang-I Lin
- Department of Physical Therapy, College of Medicine, National Cheng Kung University, Tainan, Taiwan
| | - Yi-Ju Tsai
- Department of Physical Therapy, College of Medicine, National Cheng Kung University, Tainan, Taiwan
| | - Pei-Yun Lee
- Department of Physical Therapy, College of Medicine, National Cheng Kung University, Tainan, Taiwan
| |
Collapse
|
15
|
Mantilla J, Wang D, Bargiotas I, Wang J, Cao J, Oudre L, Vidal PP. Motor style at rest and during locomotion in human. J Neurophysiol 2020; 123:2269-2284. [PMID: 32319842 DOI: 10.1152/jn.00019.2019] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Humans exhibit various motor styles that reflect their intra- and interindividual variability when implementing sensorimotor transformations. This opens important questions, such as, At what point should they be readjusted to maintain optimal motor control? Do changes in motor style reveal the onset of a pathological process and can these changes help rehabilitation and recovery? To further investigate the concept of motor style, tests were carried out to quantify posture at rest and motor control in 18 healthy subjects under four conditions: walking at three velocities (comfortable walking, walking at 4 km/h, and race walking) and running at maximum velocity. The results suggest that motor control can be conveniently decomposed into a static component (a stable configuration of the head and column with respect to the gravitational vertical) and dynamic components (head, trunk, and limb movements) in humans, as in quadrupeds, and both at rest and during locomotion. These skeletal configurations provide static markers to quantify the motor style of individuals because they exhibit large variability among subjects. Also, using four measurements (jerk, root mean square, sample entropy, and the two-thirds power law), it was shown that the dynamics were variable at both intra- and interindividual levels during locomotion. Variability increased following a head-to -toe gradient. These findings led us to select dynamic markers that could define, together with static markers, the motor style of a subject. Finally, our results support the view that postural and motor control are subserved by different neuronal networks in frontal, sagittal, and transversal planes.NEW & NOTEWORTHY During human locomotion, motor control can be conveniently decomposed into a static and dynamic components. Variable dynamics were observed at both the intra- and interindividual levels during locomotion. Variability increased following a head-to-toe gradient. Finally, our results support the view that postural and motor control are subserved by different neuronal networks in the frontal, sagittal, and transversal planes.
Collapse
Affiliation(s)
- Juan Mantilla
- Université de Paris, CNRS, SSA, École Normale Supérieure Paris-Saclay, Centre Borelli, Paris, France
| | - Danping Wang
- Institute of Information and Control, Hangzhou Dianzi University, Hangzhou, China.,Plateforme Sensorimotricité, CNRS, INSERM, Paris, France
| | - Ioannis Bargiotas
- Université de Paris, CNRS, SSA, École Normale Supérieure Paris-Saclay, Centre Borelli, Paris, France
| | - Junhong Wang
- Institute of Information and Control, Hangzhou Dianzi University, Hangzhou, China
| | - Jiuwen Cao
- Institute of Information and Control, Hangzhou Dianzi University, Hangzhou, China
| | - Laurent Oudre
- L2TI, Sorbonne Paris Nord University, Villetaneuse, France
| | - Pierre-Paul Vidal
- Université de Paris, CNRS, SSA, École Normale Supérieure Paris-Saclay, Centre Borelli, Paris, France.,Institute of Information and Control, Hangzhou Dianzi University, Hangzhou, China
| |
Collapse
|
16
|
Wibble T, Södergård U, Träisk F, Pansell T. Intensified visual clutter induces increased sympathetic signalling, poorer postural control, and faster torsional eye movements during visual rotation. PLoS One 2020; 15:e0227370. [PMID: 31900468 PMCID: PMC6941927 DOI: 10.1371/journal.pone.0227370] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2019] [Accepted: 12/17/2019] [Indexed: 11/18/2022] Open
Abstract
Many dizzy patients express a hypersensitivity to visual motion and clutter. This study aims to investigate how exposure to rotating visual clutter affects ocular torsion, vertical skewing, body-sway, the autonomic pupillary response, and the subjective feeling of discomfort to the stimulation. Sixteen healthy subjects were exposed to 20 seconds rotational visual stimulation (72 deg/s; 50 deg visual field). Visual stimuli were comprised of black lines on a white background, presented at low and high intensity levels of visual clutter, holding 19 lines and 38 lines respectively. Ocular torsion and vertical skewing were recorded using the Chronos Eye Tracker, which also measured pupil size as a reflection of the autonomic response. Postural control was evaluated by measuring body-sway area on the Wii Balance Board. Values were compared to data retrieved 20 seconds before and after the optokinetic stimulation, as subjects viewed the stationary visual scene. The high intensity stimulus resulted in significantly higher torsional velocities. Subjects who were exposed to low intensity first exhibited higher velocities for both intensities. Both pupil size and body sway increased for the higher intensity to both the moving and stationary visual scene, and were positively correlated to torsional velocity. In conclusion, exposure to visual clutter was reflected in the eye movement response, changes in postural control, and the autonomic response. This response may hold clinical utility when assessing patients suffering from visual motion hypersensitivity, while also providing some context as to why some healthy people feel discomfort in visually cluttered surroundings.
Collapse
Affiliation(s)
- Tobias Wibble
- Division of Ophthalmology and Vision, Department of Clinical Neuroscience, Marianne Bernadotte Centre, Karolinska Institutet, Stockholm, Sweden
- St Erik Eye Hospital, Stockholm, Sweden
- * E-mail:
| | - Ulrika Södergård
- Division of Ophthalmology and Vision, Department of Clinical Neuroscience, Marianne Bernadotte Centre, Karolinska Institutet, Stockholm, Sweden
| | - Frank Träisk
- Division of Ophthalmology and Vision, Department of Clinical Neuroscience, Marianne Bernadotte Centre, Karolinska Institutet, Stockholm, Sweden
- St Erik Eye Hospital, Stockholm, Sweden
| | - Tony Pansell
- Division of Ophthalmology and Vision, Department of Clinical Neuroscience, Marianne Bernadotte Centre, Karolinska Institutet, Stockholm, Sweden
- St Erik Eye Hospital, Stockholm, Sweden
| |
Collapse
|
17
|
Harquel S, Guerraz M, Barraud PA, Cian C. Modulation of alpha waves in sensorimotor cortical networks during self-motion perception evoked by different visual-vestibular conflicts. J Neurophysiol 2020; 123:346-355. [PMID: 31774351 DOI: 10.1152/jn.00237.2019] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Visually induced illusion of self-motion (vection) has been used as a tool to address neural correlates of visual-vestibular interaction. The extent to which vestibular cortical areas are deactivated during vection varies from one study to another. The main question in this study is whether such deactivation depends on the visual-vestibular conflict induced by visual motion. A visual motion about the line of sight (roll motion) induces a visual-canal conflict in upright and supine observers. An additional visual-otolith conflict arises in the upright position only, with the graviceptive inputs indicating that the head is stationary. A 96-channel electroencephalogram (EEG) was recorded in 21 participants exposed to roll motion in seated and supine positions. Meanwhile, perceptual state of self-motion was recorded. Results showed a transient decrease in the cortical sensorimotor networks' alpha activity at the onset of vection whatever the participant's position, and therefore the visual-vestibular conflict. During vection, an increase in alpha activity over parieto-occipital areas was observed in the upright condition, that is, in a condition of visual-otolith conflict. The modulation of alpha activity may be predictive of the illusion of self-motion but also may reflect the level of inhibition in the sensorimotor networks needed to reduce potential interference from vestibular conflicting inputs.NEW & NOTEWORTHY For the first time, we explored the neural correlates of different visuo-vestibular conflicts induced by visual motion using EEG. Our study highlighted a neuronal signature for illusory self-motion (vection) in the sensorimotor networks. Strong alpha activity may predict successful vection but also reflects the level of inhibition of sensorimotor networks needed to reduce potential interfering vestibular inputs. These findings would be of prime importance for simulator and virtual reality systems that induce vection.
Collapse
Affiliation(s)
- Sylvain Harquel
- Laboratoire de Psychologie et NeuroCognition (LPNC), Centre National de Recherche Scientifique (CNRS), Université Grenoble-Alpes, Grenoble, France.,IRMaGe, CNRS, Centre Hospitalier Universitaire (CHU) de Grenoble-Alpes, INSERM, Université Grenoble-Alpes, Grenoble, France
| | | | - Pierre-Alain Barraud
- Techniques de l'Ingénierie Médicale et de la Complexité - Informatique, Mathématiques et Applications, CNRS, CHU Grenoble-Alpes, Grenoble Institut d'ingénierie, Université Grenoble-Alpes, Grenoble, France
| | - Corinne Cian
- Laboratoire de Psychologie et NeuroCognition (LPNC), Centre National de Recherche Scientifique (CNRS), Université Grenoble-Alpes, Grenoble, France.,Institut de Recherche Biomédicale des Armées, Brétigny sur Orge, France
| |
Collapse
|
18
|
Fujimoto K, Ashida H. Larger Head Displacement to Optic Flow Presented in the Lower Visual Field. Iperception 2019; 10:2041669519886903. [PMID: 31803463 PMCID: PMC6876183 DOI: 10.1177/2041669519886903] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2019] [Accepted: 10/14/2019] [Indexed: 11/15/2022] Open
Abstract
Optic flow that simulates self-motion often produces postural adjustment. Although literature has suggested that human postural control depends largely on visual inputs from the lower field in the environment, effects of the vertical location of optic flow on postural responses are not well investigated. Here, we examined whether optic flow presented in the lower visual field produces stronger responses than optic flow in the upper visual field. Either expanding or contracting optic flow was presented in upper, lower, or full visual fields through an Oculus Rift head-mounted display. Head displacement and vection strength were measured. Results showed larger head displacement under the optic flow presentation in the full visual field and the lower visual field than the upper visual field, during early period of presentation of the contracting optic flow. Vection was strongest in the full visual field and weakest in the upper visual field. Our findings of lower field superiority in head displacement and vection support the notion that ecologically relevant information has a particularly important role in human postural control and self-motion perception.
Collapse
Affiliation(s)
- Kanon Fujimoto
- Department of Psychology, Graduate School of Letters, Kyoto University, Japan
| | - Hiroshi Ashida
- Department of Psychology, Graduate School of Letters, Kyoto University, Japan
| |
Collapse
|
19
|
Bronstein AM. A conceptual model of the visual control of posture. PROGRESS IN BRAIN RESEARCH 2019; 248:285-302. [PMID: 31239139 DOI: 10.1016/bs.pbr.2019.04.023] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
In order to isolate the visual contribution to the control of postural balance, experiments in which subjects are exposed to large-field visual motion (optokinetic) stimuli are reviewed. In these situations, at motion onset, the visual stimulus signals subject self-motion but inertial (vestibulo-proprioceptive) cues do not. Visually evoked postural responses (VEPR) thus induced can be quickly suppressed by cognitive status or simple repetition of the stimulus, if the inertial self-motion cues available to the subject are reliable. In the conceptual model presented here, the process of assessing the reliability, and degree of matching, of visual and inertial signals is carried out by a General comparator; in turn able to access the Gain control mechanism of the visuo-postural system. Complexity and congruency in the visual stimulus itself are assessed by a Visual comparator, e.g., the presence of motion parallax in the visual stimulus can reverse the sway response direction. VEPR can also be re-oriented according to the position of the eyes in the head and the head on the trunk. This indicates that ocular and cervical proprioceptors must also access the gain control mechanism so that visual stimuli can recruit and silence different postural muscles appropriately. The overall gain of the visuo-postural system is also influenced by less easily defined idiosyncratic factors, such as visual dependence and psychological traits; interestingly both these factors have been found to be associated with poor long term outcome in vestibular disorders. The experimental results and model presented illustrate that the visuo-postural system is a wonderful example of interaction between physics (e.g., stimuli geometry, body dynamics), neuroscience and the border zone between neurology and psycho-somatic medicine.
Collapse
Affiliation(s)
- Adolfo M Bronstein
- Neuro-Otology Unit, Division of Brain Sciences, Imperial College London, Charing Cross Hospital, London, United Kingdom.
| |
Collapse
|
20
|
Yu Y, Tucker CA, Lauer RT, Keshner EA. Influence of Visual Dependence on Inter-Segmental Coordination during Upright Stance in Cerebral Palsy. J Mot Behav 2019; 52:249-261. [PMID: 31063037 DOI: 10.1080/00222895.2019.1610860] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
The presence of visual dependence as an influential factor on the development of functional stability in ambulatory individuals with cerebral palsy (CP) was studied in 22 adults with spastic bilateral CP, 11 of whom were considered visually dependent, and 18 healthy adults. Participants stood upright during pitch plane disturbances of the visual field and support surface. Intersegmental coordination behaviors were assessed by fitting trajectories of adjacent body segments to an ellipse. Mixed-model repeated measures ANOVAs were performed on ellipse orientation angle and area. Dissimilar stabilizing strategies adopted by the two groups with CP imply that visual dependence impacts postural control. Postural reorganization in response to visual flow in all groups indicates that we cannot ignore perceptual aspects of postural control when designing therapeutic interventions.
Collapse
Affiliation(s)
- Yawen Yu
- Department of Physical Therapy, Temple University, Philadelphia, Pennsylvania, USA.,Shriners Hospitals for Children, Philadelphia, Pennsylvania, USA.,Department of Occupational Therapy, Colorado State University, Fort Collins, Colorado, USA
| | - Carole A Tucker
- Department of Physical Therapy, Temple University, Philadelphia, Pennsylvania, USA.,Shriners Hospitals for Children, Philadelphia, Pennsylvania, USA.,Department of Electrical and Computer Engineering, Temple University, Philadelphia, Pennsylvania, USA
| | - Richard T Lauer
- Department of Physical Therapy, Temple University, Philadelphia, Pennsylvania, USA
| | - Emily A Keshner
- Department of Physical Therapy, Temple University, Philadelphia, Pennsylvania, USA
| |
Collapse
|
21
|
Britton Z, Arshad Q. Vestibular and Multi-Sensory Influences Upon Self-Motion Perception and the Consequences for Human Behavior. Front Neurol 2019; 10:63. [PMID: 30899238 PMCID: PMC6416181 DOI: 10.3389/fneur.2019.00063] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2018] [Accepted: 01/17/2019] [Indexed: 11/16/2022] Open
Abstract
In this manuscript, we comprehensively review both the human and animal literature regarding vestibular and multi-sensory contributions to self-motion perception. This covers the anatomical basis and how and where the signals are processed at all levels from the peripheral vestibular system to the brainstem and cerebellum and finally to the cortex. Further, we consider how and where these vestibular signals are integrated with other sensory cues to facilitate self-motion perception. We conclude by demonstrating the wide-ranging influences of the vestibular system and self-motion perception upon behavior, namely eye movement, postural control, and spatial awareness as well as new discoveries that such perception can impact upon numerical cognition, human affect, and bodily self-consciousness.
Collapse
Affiliation(s)
- Zelie Britton
- Department of Neuro-Otology, Charing Cross Hospital, Imperial College London, London, United Kingdom
| | - Qadeer Arshad
- Department of Neuro-Otology, Charing Cross Hospital, Imperial College London, London, United Kingdom
| |
Collapse
|
22
|
Cooper N, Cant I, White MD, Meyer GF. Perceptual assessment of environmental stability modulates postural sway. PLoS One 2018; 13:e0206218. [PMID: 30412590 PMCID: PMC6226165 DOI: 10.1371/journal.pone.0206218] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2018] [Accepted: 10/09/2018] [Indexed: 11/19/2022] Open
Abstract
We actively maintain postural equilibrium in everyday life, and, although we are unaware of the underlying processing, there is increasing evidence for cortical involvement in this postural control. Converging evidence shows that we make appropriate use of 'postural anchors', for example static objects in the environment, to stabilise our posture. Visually evoked postural responses (VEPR) that are caused when we counteract the illusory perception of self-motion in space (vection) are modulated in the presence of postural anchors and therefore provide a convenient behavioural measure. The aim of this study is to evaluate the factors influencing visual appraisal of the suitability of postural anchors. We are specifically interested in the effect of perceived 'reality' in VR the expected 'stability' of visual anchors. To explore the effect of 'reality' we introduced an accommodation-vergence conflict. We show that VEPR are appropriately modulated only when virtual visual 'anchors' are rendered such that vergence and accommodation cues are consistent. In a second experiment we directly test whether cognitive assessment of the likely stability of real perceptual anchors (we contrast a 'teapot on a stand' and a 'helium balloon') affects VEPR. We show that the perceived positional stability of environmental anchors modulate postural responses. Our results confirm previous findings showing that postural sway is modulated by the configuration of the environment and further show that an assessment of the stability and reality of the environment plays an important role in this process. On this basis we propose design guidelines for VR systems, in particular we argue that accommodation-vergence conflicts should be minimised and that high quality motion tracking and rendering are essential for high fidelity VR.
Collapse
Affiliation(s)
- Natalia Cooper
- Construction Research Centre, National Research Council Canada, Ottawa, ON, Canada
| | - Iain Cant
- Virtual Engineering Centre, Hartree Centre Sci-Tech Daresbury, Keckwick Lane, Daresbury, Warrington, United Kingdom
| | - Mark D. White
- School of Engineering, Brownlow Hill, University of Liverpool, Liverpool, United Kingdom
| | - Georg F. Meyer
- Psychological Sciences, University of Liverpool, United Kingdom
| |
Collapse
|
23
|
Yu Y, Lauer RT, Tucker CA, Thompson ED, Keshner EA. Visual dependence affects postural sway responses to continuous visual field motion in individuals with cerebral palsy. Dev Neurorehabil 2018; 21:531-541. [PMID: 29341797 PMCID: PMC6237184 DOI: 10.1080/17518423.2018.1424265] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
UNLABELLED The current study aimed to explore the impact of visual dependence on sensorimotor coupling of postural sway and visual motion in adults and teens with spastic cerebral palsy (CP). We hypothesized that individuals with CP would exhibit greater magnitudes of sway than healthy individuals, and the presence of visual dependence (VD) would produce instability in the direction of visual motion. Participants stood in a virtual environment in which the visual scene remained static or continuously rotated 30 degree/second in pitch-up or pitch-down. Increased center of pressure and center of mass responses were observed in the direction of visual scene motion in those with CP. Those with VD exhibited reduced frequency responses in anterior-posterior direction than those who were visually independent. VD suggests deficient sensorimotor integration that could contribute to postural instability and reduced motor function. Individuals with CP who are visually dependent may benefit from more sensory focused rehabilitation strategies. ABBREVIATIONS AP, anterior-posterior; CP, cerebral palsy; COM, center of mass; COP, center of pressure; MDF, median frequency; ML, mediolateral; PD, pitch down (nose down) rotation; PU, pitch up (nose up) rotation; RFT, rod and frame test; RMS, root mean square; SLP, slope of the fitted line; TD, typical development; VD, visual dependence; VI, visual independence; VOR, vestibulo-ocular reflex; VPI, visual perceptual impairment.
Collapse
Affiliation(s)
- Yawen Yu
- Department of Physical Therapy, Temple University, Philadelphia, PA,Shriners Hospitals for Children – Philadelphia, Philadelphia, PA
| | - Richard T. Lauer
- Department of Physical Therapy, Temple University, Philadelphia, PA
| | - Carole A. Tucker
- Department of Physical Therapy, Temple University, Philadelphia, PA,Shriners Hospitals for Children – Philadelphia, Philadelphia, PA,Department of Electrical and Computer Engineering, Temple University, Philadelphia, PA
| | - Elizabeth D. Thompson
- Department of Physical Therapy, Temple University, Philadelphia, PA,Department of Kinesiology, Temple University, Philadelphia, PA
| | - Emily A. Keshner
- Department of Physical Therapy, Temple University, Philadelphia, PA
| |
Collapse
|
24
|
Hand movement illusions show changes in sensory reliance and preservation of multisensory integration with age for kinaesthesia. Neuropsychologia 2018; 119:45-58. [DOI: 10.1016/j.neuropsychologia.2018.07.027] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2017] [Revised: 07/18/2018] [Accepted: 07/25/2018] [Indexed: 11/20/2022]
|
25
|
Tinga AM, Jansen C, van der Smagt MJ, Nijboer TCW, van Erp JBF. Inducing circular vection with tactile stimulation encircling the waist. Acta Psychol (Amst) 2018; 182:32-38. [PMID: 29128511 DOI: 10.1016/j.actpsy.2017.11.007] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2017] [Revised: 08/22/2017] [Accepted: 11/05/2017] [Indexed: 11/15/2022] Open
Abstract
In general, moving sensory stimuli (visual and auditory) can induce illusory sensations of self-motion (i.e. vection) in the direction opposite of the sensory stimulation. The aim of the current study was to examine whether tactile stimulation encircling the waist could induce circular vection (around the body's yaw axis) and to examine whether this type of stimulation would influence participants' walking trajectory and balance. We assessed the strength and direction of perceived self-motion while vision was blocked and while either receiving tactile stimulation encircling the waist clockwise or counterclockwise or no tactile stimulation. Additionally, we assessed participants' walking trajectory and balance while receiving these different stimulations. Tactile stimulation encircling the waist was found to lead to self-reported circular vection in a subset of participants. In this subset of participants, circular vection was on average experienced in the same direction as the tactile stimulation. Additionally, perceived rotatory self-motion in participants that reported circular vection correlated with balance (i.e., sway velocity and the standard error of the mean in the medio-lateral dimension). The fact that, in this subset of participants, subjective reports of vection correlated with objective outcome measures indicates that tactile stimulation encircling the waist might indeed be able to induced circular vection.
Collapse
Affiliation(s)
- Angelica M Tinga
- TNO, Department of Perceptual and Cognitive Systems, Soesterberg, The Netherlands; Utrecht University, Department of Experimental Psychology, Helmholtz Institute, Utrecht, The Netherlands; Tilburg University, Department of Communication and Information Sciences, Tilburg, The Netherlands.
| | - Chris Jansen
- TNO, Department of Perceptual and Cognitive Systems, Soesterberg, The Netherlands
| | - Maarten J van der Smagt
- Utrecht University, Department of Experimental Psychology, Helmholtz Institute, Utrecht, The Netherlands
| | - Tanja C W Nijboer
- Utrecht University, Department of Experimental Psychology, Helmholtz Institute, Utrecht, The Netherlands; Brain Center Rudolf Magnus, and Center of Excellence for Rehabilitation Medicine, University Medical Center Utrecht, and De Hoogstraat Rehabilitation, The Netherlands
| | - Jan B F van Erp
- TNO, Department of Perceptual and Cognitive Systems, Soesterberg, The Netherlands; Twente University, Department of Human Media Interaction, Enschede, The Netherlands
| |
Collapse
|
26
|
Kheradmand A, Winnick A. Perception of Upright: Multisensory Convergence and the Role of Temporo-Parietal Cortex. Front Neurol 2017; 8:552. [PMID: 29118736 PMCID: PMC5660972 DOI: 10.3389/fneur.2017.00552] [Citation(s) in RCA: 54] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2017] [Accepted: 09/28/2017] [Indexed: 12/18/2022] Open
Abstract
We inherently maintain a stable perception of the world despite frequent changes in the head, eye, and body positions. Such "orientation constancy" is a prerequisite for coherent spatial perception and sensorimotor planning. As a multimodal sensory reference, perception of upright represents neural processes that subserve orientation constancy through integration of sensory information encoding the eye, head, and body positions. Although perception of upright is distinct from perception of body orientation, they share similar neural substrates within the cerebral cortical networks involved in perception of spatial orientation. These cortical networks, mainly within the temporo-parietal junction, are crucial for multisensory processing and integration that generate sensory reference frames for coherent perception of self-position and extrapersonal space transformations. In this review, we focus on these neural mechanisms and discuss (i) neurobehavioral aspects of orientation constancy, (ii) sensory models that address the neurophysiology underlying perception of upright, and (iii) the current evidence for the role of cerebral cortex in perception of upright and orientation constancy, including findings from the neurological disorders that affect cortical function.
Collapse
Affiliation(s)
- Amir Kheradmand
- Department of Neurology, The Johns Hopkins University School of Medicine, Baltimore, MD, United States
- Department of Otolaryngology – Head and Neck Surgery, The Johns Hopkins University School of Medicine, Baltimore, MD, United States
| | - Ariel Winnick
- Department of Neurology, The Johns Hopkins University School of Medicine, Baltimore, MD, United States
| |
Collapse
|
27
|
Abstract
Effects of visual roll-motion on postural sway and the subjective visual vertical (SVV) often is studied using mechanical devices, whereas electronic displays offer cheaper and more flexible alternatives. These devices typically emit and reflect light scattered by the edges of the screen, providing Earth-fixed cues of verticality. These cues may decrease the effects of rotating stimuli, a possibility that has not been studied explicitly before in one experimental design. We exposed 16 participants to a visual dot pattern, either stationary, or rotating in roll, that was or was not surrounded by a visible Earth-fixed reference frame. To eliminate unintended visual cues, the experiment was performed in complete darkness and participants wore neutral density goggles passing only 1% of light. Postural sway was measured using a force platform. SVV measurements were obtained from a visible rod. To monitor the participants, motion sickness severity was obtained with an 11-point rating scale. Results showed that the presence of an Earth-fixed frame significantly decreased the effect of the rotating pattern on postural sway and SVV deviations. Therefore, when studying subjective verticality related effects of visual stimuli, it is imperative that all visual Earth-fixed cues are not just minimized but completely eliminated. The observation that an Earth-fixed frame significantly decreased the effect of the rotating pattern on both postural sway and the SVV points towards a common neural origin, possibly involving a neural representation of verticality. Finally, we showed that an electronic screen can yield similar effect sizes as those taken from the literature using mechanical devices.
Collapse
|
28
|
Balestrucci P, Daprati E, Lacquaniti F, Maffei V. Effects of visual motion consistent or inconsistent with gravity on postural sway. Exp Brain Res 2017; 235:1999-2010. [PMID: 28326440 DOI: 10.1007/s00221-017-4942-3] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2017] [Accepted: 03/11/2017] [Indexed: 11/25/2022]
Abstract
Vision plays an important role in postural control, and visual perception of the gravity-defined vertical helps maintaining upright stance. In addition, the influence of the gravity field on objects' motion is known to provide a reference for motor and non-motor behavior. However, the role of dynamic visual cues related to gravity in the control of postural balance has been little investigated. In order to understand whether visual cues about gravitational acceleration are relevant for postural control, we assessed the relation between postural sway and visual motion congruent or incongruent with gravity acceleration. Postural sway of 44 healthy volunteers was recorded by means of force platforms while they watched virtual targets moving in different directions and with different accelerations. Small but significant differences emerged in sway parameters with respect to the characteristics of target motion. Namely, for vertically accelerated targets, gravitational motion (GM) was associated with smaller oscillations of the center of pressure than anti-GM. The present findings support the hypothesis that not only static, but also dynamic visual cues about direction and magnitude of the gravitational field are relevant for balance control during upright stance.
Collapse
Affiliation(s)
- Priscilla Balestrucci
- Laboratory of Neuromotor Physiology, IRCCS Santa Lucia Foundation, Via Ardeatina 306, 00179, Rome, Italy. .,Centre of Space BioMedicine, University of Rome Tor Vergata, Via Montpellier 1, 00133, Rome, Italy.
| | - Elena Daprati
- Centre of Space BioMedicine, University of Rome Tor Vergata, Via Montpellier 1, 00133, Rome, Italy.,Department of Systems Medicine, University of Rome Tor Vergata, Via Montpellier 1, 00133, Rome, Italy
| | - Francesco Lacquaniti
- Laboratory of Neuromotor Physiology, IRCCS Santa Lucia Foundation, Via Ardeatina 306, 00179, Rome, Italy.,Centre of Space BioMedicine, University of Rome Tor Vergata, Via Montpellier 1, 00133, Rome, Italy.,Department of Systems Medicine, University of Rome Tor Vergata, Via Montpellier 1, 00133, Rome, Italy
| | - Vincenzo Maffei
- Laboratory of Neuromotor Physiology, IRCCS Santa Lucia Foundation, Via Ardeatina 306, 00179, Rome, Italy
| |
Collapse
|
29
|
Mittermaier C, Schindler M, Loader B, Waldhoer T, Ambrozy C, Crevenna R, Pieber K. Unique approach to sensorimotor training with a new device combining air cushion with stochastic translations-A prospective randomized controlled clinical trial. Gait Posture 2017; 52:153-158. [PMID: 27914309 DOI: 10.1016/j.gaitpost.2016.11.038] [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: 11/24/2015] [Revised: 11/16/2016] [Accepted: 11/24/2016] [Indexed: 02/02/2023]
Abstract
Sensorimotor training with a wide variety of available devices represents an important component in rehabilitation and prevention of different sports injuries and chronic diseases. The purpose of this study was to evaluate the effects of a sensorimotor training with a newly developed device, which consists of an instable platform moving on an air cushion, providing dynamic balance training by tilting and unanticipated stochastic translations on postural control. Seventy-two healthy young subjects were included in this prospective, randomized, controlled, and observer-blinded study. Balance was objectively assessed by posturography and Functional Reach Test (FRT). Additionally we evaluated the subjective rating of balance. After randomization the sensorimotor training group performed a training program on the new device over a 5-6 week study period. After this time improvement in objective and subjective measurements as a result of training became evident. A significant difference in challenging posturographic parameters (Sensory Organization Test 5: training group 5.32±5.25 vs. control group 1.78±5.05, p=0.006 and Head Shake Sensory Organization Test 5: training group 11.94±8.97 vs. control group 5.41±10.17, p=0.01) as well as a significant difference in the FRT (training group 3.34±3.35cm vs. control group 0.01±2.97cm, p=0.0001) was found. Subjective assessment revealed a significant improvement in the participants' rating of balance and alteration of balance. Subjects showed a high satisfaction with the new training device. Our findings suggest that the newly developed device could be a promising option for sensorimotor training to improve postural control.
Collapse
Affiliation(s)
- Christian Mittermaier
- Department of Physical Medicine and Rehabilitation, Medical University of Vienna, Austria; Institute of Physical Medicine and Rehabilitation, Kepler University Hospital, Linz, Austria
| | - Maximilian Schindler
- Department of Physical Medicine and Rehabilitation, Medical University of Vienna, Austria
| | - Benjamin Loader
- Department of Otorhinolaryngology, Medical University of Vienna, Austria
| | - Thomas Waldhoer
- Department of Epidemiology, Center of Public Health, Medical University of Vienna, Austria
| | - Clemens Ambrozy
- Department of Physical Medicine and Rehabilitation, Medical University of Vienna, Austria
| | - Richard Crevenna
- Department of Physical Medicine and Rehabilitation, Medical University of Vienna, Austria
| | - Karin Pieber
- Department of Physical Medicine and Rehabilitation, Medical University of Vienna, Austria.
| |
Collapse
|
30
|
Dennison MS, D'Zmura M. Cybersickness without the wobble: Experimental results speak against postural instability theory. APPLIED ERGONOMICS 2017; 58:215-223. [PMID: 27633216 DOI: 10.1016/j.apergo.2016.06.014] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/11/2015] [Revised: 06/10/2016] [Accepted: 06/24/2016] [Indexed: 06/06/2023]
Abstract
It has been suggested that postural instability is necessary for cybersickness to occur. Seated and standing subjects used a head-mounted display to view a virtual tunnel that rotated about their line of sight. We found that the offset direction of perceived vertical settings matched the direction of the tunnel's rotation, so replicating earlier findings. Increasing rotation speed caused cybersickness to increase, but had no significant impact on perceived vertical settings. Postural sway during rotation was similar to postural sway during rest. While a minority of subjects exhibited postural sway in response to the onset of tunnel rotation, the majority did not. Furthermore, cybersickness increased with rotation speed similarly for the seated and standing conditions. Finally, subjects with greater levels of cybersickness exhibited less variation in postural sway. These results lead us to conclude that the link between postural instability and cybersickness is a weak one in the present experiment.
Collapse
Affiliation(s)
- Mark Stephen Dennison
- Cognitive NeuroSystems Laboratory, University of California, Irvine, Department of Cognitive Sciences, Irvine, CA, USA.
| | - Michael D'Zmura
- Cognitive NeuroSystems Laboratory, University of California, Irvine, Department of Cognitive Sciences, Irvine, CA, USA
| |
Collapse
|
31
|
Chancel M, Blanchard C, Guerraz M, Montagnini A, Kavounoudias A. Optimal visuotactile integration for velocity discrimination of self-hand movements. J Neurophysiol 2016; 116:1522-1535. [PMID: 27385802 DOI: 10.1152/jn.00883.2015] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2015] [Accepted: 07/06/2016] [Indexed: 11/22/2022] Open
Abstract
Illusory hand movements can be elicited by a textured disk or a visual pattern rotating under one's hand, while proprioceptive inputs convey immobility information (Blanchard C, Roll R, Roll JP, Kavounoudias A. PLoS One 8: e62475, 2013). Here, we investigated whether visuotactile integration can optimize velocity discrimination of illusory hand movements in line with Bayesian predictions. We induced illusory movements in 15 volunteers by visual and/or tactile stimulation delivered at six angular velocities. Participants had to compare hand illusion velocities with a 5°/s hand reference movement in an alternative forced choice paradigm. Results showed that the discrimination threshold decreased in the visuotactile condition compared with unimodal (visual or tactile) conditions, reflecting better bimodal discrimination. The perceptual strength (gain) of the illusions also increased: the stimulation required to give rise to a 5°/s illusory movement was slower in the visuotactile condition compared with each of the two unimodal conditions. The maximum likelihood estimation model satisfactorily predicted the improved discrimination threshold but not the increase in gain. When we added a zero-centered prior, reflecting immobility information, the Bayesian model did actually predict the gain increase but systematically overestimated it. Interestingly, the predicted gains better fit the visuotactile performances when a proprioceptive noise was generated by covibrating antagonist wrist muscles. These findings show that kinesthetic information of visual and tactile origins is optimally integrated to improve velocity discrimination of self-hand movements. However, a Bayesian model alone could not fully describe the illusory phenomenon pointing to the crucial importance of the omnipresent muscle proprioceptive cues with respect to other sensory cues for kinesthesia.
Collapse
Affiliation(s)
- M Chancel
- LNIA UMR 7260, Aix Marseille Université-Centre National de la Recherche Scientifique (CNRS), Marseille, France; LPNC UMR 5105, Université Savoie Mont Blanc-CNRS, Chambéry, France
| | - C Blanchard
- School of Psychology, University of Nottingham, Nottingham, United Kingdom; and
| | - M Guerraz
- LPNC UMR 5105, Université Savoie Mont Blanc-CNRS, Chambéry, France
| | - A Montagnini
- INT UMR 7289, Aix Marseille Université-CNRS, Marseille, France
| | - A Kavounoudias
- LNIA UMR 7260, Aix Marseille Université-Centre National de la Recherche Scientifique (CNRS), Marseille, France;
| |
Collapse
|
32
|
Agostini V, Sbrollini A, Cavallini C, Busso A, Pignata G, Knaflitz M. The role of central vision in posture: Postural sway adaptations in Stargardt patients. Gait Posture 2016; 43:233-8. [PMID: 26514831 DOI: 10.1016/j.gaitpost.2015.10.003] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/20/2015] [Revised: 09/29/2015] [Accepted: 10/09/2015] [Indexed: 02/02/2023]
Abstract
The role of central and peripheral vision in the maintenance of upright stance is debated in literature. Stargardt disease causes visual deficits affecting the central field, but leaving unaltered a patient's peripheral vision. Hence, the study of this rare pathology gives the opportunity to selectively investigate the role of central vision in posture. Postural sway in quiet stance was analyzed in 10 Stargardt patients and 10 control subjects, in three different conditions: (1) eyes closed, (2) eyes open, gazing at a fixed target, and (3) eyes open, tracking a moving target. Stargardt patients outperformed controls in the condition with eyes closed, showing a reduced root mean square (RMS) of the medio-lateral COP displacement, while their performance was not significantly different from controls in the antero-posterior direction. There were no significant differences between patients and controls in open eyes conditions. These results suggest that Stargardt patients adapted to a different visual-somatosensory integration, relying less on vision, especially in the medio-lateral direction. Hence, the central vision seems to affect mostly the medio-lateral direction of postural sway. This finding supports the plausibility of the "functional sensitivity hypothesis", that assigns complementary roles to central and peripheral vision in the control of posture.
Collapse
Affiliation(s)
- Valentina Agostini
- Dipartimento di Elettronica e Telecomunicazioni, Politecnico di Torino, Corso Duca degli Abruzzi 24, 10129 Torino, Italy.
| | - Agnese Sbrollini
- Dipartimento di Elettronica e Telecomunicazioni, Politecnico di Torino, Corso Duca degli Abruzzi 24, 10129 Torino, Italy
| | - Chanda Cavallini
- Clinica C. Sperino, Ospedale Oftalmico di Torino, Via Juvarra 19, 10122 Torino, Italy
| | - Alessandra Busso
- Clinica C. Sperino, Ospedale Oftalmico di Torino, Via Juvarra 19, 10122 Torino, Italy
| | - Giulia Pignata
- Clinica C. Sperino, Ospedale Oftalmico di Torino, Via Juvarra 19, 10122 Torino, Italy
| | - Marco Knaflitz
- Dipartimento di Elettronica e Telecomunicazioni, Politecnico di Torino, Corso Duca degli Abruzzi 24, 10129 Torino, Italy
| |
Collapse
|
33
|
Lubeck AJA, Bos JE, Stins JF. Interaction between Depth Order and Density Affects Vection and Postural Sway. PLoS One 2015; 10:e0144034. [PMID: 26630658 PMCID: PMC4668089 DOI: 10.1371/journal.pone.0144034] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2015] [Accepted: 11/12/2015] [Indexed: 12/02/2022] Open
Abstract
Objective Vection, a feeling of self-motion while being physically stationary, and postural sway can be modulated by various visual factors. Moreover, vection and postural sway are often found to be closely related when modulated by such visual factors, suggesting a common neural mechanism. One well-known visual factor is the depth order of the stimulus. The density, i.e. number of objects per unit area, is proposed to interact with the depth order in the modulation of vection and postural sway, which has only been studied to a limited degree. Methods We therefore exposed 17 participants to 18 different stimuli containing a stationary pattern and a pattern rotating around the naso-occipital axis. The density of both patterns was varied between 10 and 90%; the densities combined always added up to 100%. The rotating pattern occluded or was occluded by the stationary pattern, suggesting foreground or background motion, respectively. During pattern rotation participants reported vection by pressing a button, and postural sway was recorded using a force plate. Results Participants always reported more vection and swayed significantly more when rotation was perceived in the background and when the rotating pattern increased in density. As hypothesized, we found that the perceived depth order interacted with pattern density. A pattern rotating in the background with a density between 60 and 80% caused significantly more vection and postural sway than when it was perceived to rotate in the foreground. Conclusions The findings suggest that the ratio between fore- and background pattern densities is an important factor in the interaction with the depth order, and it is not the density of rotating pattern per se. Moreover, the observation that vection and postural sway were modulated in a similar way points towards a common neural origin regulating both variables.
Collapse
Affiliation(s)
- Astrid J. A. Lubeck
- Department of Human Movement Sciences, Faculty of Behavioural and Movement Sciences, Vrije Universiteit Amsterdam, MOVE Research Institute Amsterdam, Amsterdam, The Netherlands
- * E-mail:
| | - Jelte E. Bos
- Department of Human Movement Sciences, Faculty of Behavioural and Movement Sciences, Vrije Universiteit Amsterdam, MOVE Research Institute Amsterdam, Amsterdam, The Netherlands
- TNO Perceptual and Cognitive Systems, Soesterberg, The Netherlands
| | - John F. Stins
- Department of Human Movement Sciences, Faculty of Behavioural and Movement Sciences, Vrije Universiteit Amsterdam, MOVE Research Institute Amsterdam, Amsterdam, The Netherlands
| |
Collapse
|
34
|
Cian C, Gianocca V, Barraud PA, Guerraz M, Bresciani JP. Bioceramic fabrics improve quiet standing posture and handstand stability in expert gymnasts. Gait Posture 2015; 42:419-23. [PMID: 26234473 DOI: 10.1016/j.gaitpost.2015.07.008] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/25/2014] [Revised: 04/09/2015] [Accepted: 07/13/2015] [Indexed: 02/02/2023]
Abstract
Bioceramic fabrics have been claimed to improve blood circulation, thermoregulation and muscle relaxation, thereby also improving muscular activity. Here we tested whether bioceramic fabrics have an effect on postural control and contribute to improve postural stability. In Experiment 1, we tested whether bioceramic fabrics contribute to reduce body-sway when maintaining standard standing posture. In Experiment 2, we measured the effect of bioceramic fabrics on body-sway when maintaining a more instable posture, namely a handstand hold. For both experiments, postural oscillations were measured using a force platform with four strain gauges that recorded the displacements of the center of pressure (CoP) in the horizontal plane. In half of the trials, the participants wore a full-body second skin suit containing a bioceramic layer. In the other half of the trials, they wore a 'placebo' second skin suit that had the same cut, appearance and elasticity as the bioceramic suit but did not contain the bioceramic layer. In both experiments, the surface of displacement of the CoP was significantly smaller when participants were wearing the bioceramic suit than when they were wearing the placebo suit. The results suggest that bioceramic fabrics do have an effect on postural control and improve postural stability.
Collapse
Affiliation(s)
- C Cian
- Institut de Recherche Biomédicale des Armées, 91223 Brétigny sur Orge, France; Univ Grenoble Alpes, LPNC, F-38000 Grenoble, France; CNRS, LPNC, F-38000 Grenoble, France
| | - V Gianocca
- University of Fribourg, Department of Medicine, Fribourg, Switzerland
| | - P A Barraud
- Institut de Recherche Biomédicale des Armées, 91223 Brétigny sur Orge, France; CNRS, TIMC-IMAG, F-38000 Grenoble, France
| | - M Guerraz
- CNRS, LPNC, F-38000 Grenoble, France; Univ Savoie Mont Blanc, LPNC, F-73000 Chambéry, France.
| | - J P Bresciani
- CNRS, LPNC, F-38000 Grenoble, France; University of Fribourg, Department of Medicine, Fribourg, Switzerland
| |
Collapse
|
35
|
Imaizumi S, Honma M, Hibino H, Koyama S. Illusory visual motion stimulus elicits postural sway in migraine patients. Front Psychol 2015; 6:542. [PMID: 25972832 PMCID: PMC4411888 DOI: 10.3389/fpsyg.2015.00542] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2015] [Accepted: 04/15/2015] [Indexed: 11/13/2022] Open
Abstract
Although the perception of visual motion modulates postural control, it is unknown whether illusory visual motion elicits postural sway. The present study examined the effect of illusory motion on postural sway in patients with migraine, who tend to be sensitive to it. We measured postural sway for both migraine patients and controls while they viewed static visual stimuli with and without illusory motion. The participants' postural sway was measured when they closed their eyes either immediately after (Experiment 1), or 30 s after (Experiment 2), viewing the stimuli. The patients swayed more than the controls when they closed their eyes immediately after viewing the illusory motion (Experiment 1), and they swayed less than the controls when they closed their eyes 30 s after viewing it (Experiment 2). These results suggest that static visual stimuli with illusory motion can induce postural sway that may last for at least 30 s in patients with migraine.
Collapse
Affiliation(s)
- Shu Imaizumi
- Graduate School of Engineering, Chiba University Chiba, Japan ; Japan Society for the Promotion of Science Tokyo, Japan
| | | | - Haruo Hibino
- Graduate School of Engineering, Chiba University Chiba, Japan
| | - Shinichi Koyama
- Graduate School of Engineering, Chiba University Chiba, Japan ; School of Medicine, Showa University Tokyo, Japan ; School of Mechanical and Aerospace Engineering, Nanyang Technological University, Singapore Singapore
| |
Collapse
|
36
|
Keshavarz B, Riecke BE, Hettinger LJ, Campos JL. Vection and visually induced motion sickness: how are they related? Front Psychol 2015; 6:472. [PMID: 25941509 PMCID: PMC4403286 DOI: 10.3389/fpsyg.2015.00472] [Citation(s) in RCA: 142] [Impact Index Per Article: 15.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2014] [Accepted: 04/01/2015] [Indexed: 11/13/2022] Open
Abstract
The occurrence of visually induced motion sickness has been frequently linked to the sensation of illusory self-motion (vection), however, the precise nature of this relationship is still not fully understood. To date, it is still a matter of debate as to whether vection is a necessary prerequisite for visually induced motion sickness (VIMS). That is, can there be VIMS without any sensation of self-motion? In this paper, we will describe the possible nature of this relationship, review the literature that addresses this relationship (including theoretical accounts of vection and VIMS), and offer suggestions with respect to operationally defining and reporting these phenomena in future.
Collapse
Affiliation(s)
- Behrang Keshavarz
- Intelligent Design for Adaptation, Participation and Technology (iDAPT), Research Department, Toronto Rehabilitation Institute, University Health Network , Toronto, ON, Canada
| | - Bernhard E Riecke
- School of Interactive Arts and Technology, Simon Fraser University , Surrey, BC, Canada
| | - Lawrence J Hettinger
- Center for Behavioral Sciences, Liberty Mutual Research Institute for Safety , Hopkinton, MA, USA
| | - Jennifer L Campos
- Intelligent Design for Adaptation, Participation and Technology (iDAPT), Research Department, Toronto Rehabilitation Institute, University Health Network , Toronto, ON, Canada ; Department of Psychology, University of Toronto , Toronto, ON, Canada
| |
Collapse
|
37
|
Palmisano S, Allison RS, Schira MM, Barry RJ. Future challenges for vection research: definitions, functional significance, measures, and neural bases. Front Psychol 2015; 6:193. [PMID: 25774143 PMCID: PMC4342884 DOI: 10.3389/fpsyg.2015.00193] [Citation(s) in RCA: 75] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2014] [Accepted: 02/07/2015] [Indexed: 11/25/2022] Open
Abstract
This paper discusses four major challenges facing modern vection research. Challenge 1 (Defining Vection) outlines the different ways that vection has been defined in the literature and discusses their theoretical and experimental ramifications. The term vection is most often used to refer to visual illusions of self-motion induced in stationary observers (by moving, or simulating the motion of, the surrounding environment). However, vection is increasingly being used to also refer to non-visual illusions of self-motion, visually mediated self-motion perceptions, and even general subjective experiences (i.e., “feelings”) of self-motion. The common thread in all of these definitions is the conscious subjective experience of self-motion. Thus, Challenge 2 (Significance of Vection) tackles the crucial issue of whether such conscious experiences actually serve functional roles during self-motion (e.g., in terms of controlling or guiding the self-motion). After more than 100 years of vection research there has been surprisingly little investigation into its functional significance. Challenge 3 (Vection Measures) discusses the difficulties with existing subjective self-report measures of vection (particularly in the context of contemporary research), and proposes several more objective measures of vection based on recent empirical findings. Finally, Challenge 4 (Neural Basis) reviews the recent neuroimaging literature examining the neural basis of vection and discusses the hurdles still facing these investigations.
Collapse
Affiliation(s)
- Stephen Palmisano
- School of Psychology, University of Wollongong Wollongong, NSW, Australia
| | - Robert S Allison
- Department of Electrical Engineering and Computer Science, York University Toronto, ON, Canada
| | - Mark M Schira
- School of Psychology, University of Wollongong Wollongong, NSW, Australia
| | - Robert J Barry
- School of Psychology, University of Wollongong Wollongong, NSW, Australia
| |
Collapse
|
38
|
Apthorp D, Nagle F, Palmisano S. Chaos in balance: non-linear measures of postural control predict individual variations in visual illusions of motion. PLoS One 2014; 9:e113897. [PMID: 25462216 PMCID: PMC4252150 DOI: 10.1371/journal.pone.0113897] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2014] [Accepted: 10/31/2014] [Indexed: 11/18/2022] Open
Abstract
Visually-induced illusions of self-motion (vection) can be compelling for some people, but they are subject to large individual variations in strength. Do these variations depend, at least in part, on the extent to which people rely on vision to maintain their postural stability? We investigated by comparing physical posture measures to subjective vection ratings. Using a Bertec balance plate in a brightly-lit room, we measured 13 participants' excursions of the centre of foot pressure (CoP) over a 60-second period with eyes open and with eyes closed during quiet stance. Subsequently, we collected vection strength ratings for large optic flow displays while seated, using both verbal ratings and online throttle measures. We also collected measures of postural sway (changes in anterior-posterior CoP) in response to the same visual motion stimuli while standing on the plate. The magnitude of standing sway in response to expanding optic flow (in comparison to blank fixation periods) was predictive of both verbal and throttle measures for seated vection. In addition, the ratio between eyes-open and eyes-closed CoP excursions during quiet stance (using the area of postural sway) significantly predicted seated vection for both measures. Interestingly, these relationships were weaker for contracting optic flow displays, though these produced both stronger vection and more sway. Next we used a non-linear analysis (recurrence quantification analysis, RQA) of the fluctuations in anterior-posterior position during quiet stance (both with eyes closed and eyes open); this was a much stronger predictor of seated vection for both expanding and contracting stimuli. Given the complex multisensory integration involved in postural control, our study adds to the growing evidence that non-linear measures drawn from complexity theory may provide a more informative measure of postural sway than the conventional linear measures.
Collapse
Affiliation(s)
- Deborah Apthorp
- Research School of Psychology, College of Medicine, Biology & Environment, Australian National University, Canberra, Australian Capital Territory, Australia
- School of Psychology, Faculty of Social Sciences, University of Wollongong, Wollongong, New South Wales, Australia
| | - Fintan Nagle
- Centre for Mathematics, Physics and Engineering in the Life Sciences and Experimental Biology, University College London, London, United Kingdom
| | - Stephen Palmisano
- School of Psychology, Faculty of Social Sciences, University of Wollongong, Wollongong, New South Wales, Australia
| |
Collapse
|
39
|
Holten V, van der Smagt MJ, Donker SF, Verstraten FAJ. Illusory motion of the motion aftereffect induces postural sway. Psychol Sci 2014; 25:1831-4. [PMID: 25037962 DOI: 10.1177/0956797614540177] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
|
40
|
Horslen BC, Dakin CJ, Inglis JT, Blouin JS, Carpenter MG. Modulation of human vestibular reflexes with increased postural threat. J Physiol 2014; 592:3671-85. [PMID: 24973412 DOI: 10.1113/jphysiol.2014.270744] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
Anxiety and arousal have been shown to facilitate human vestibulo-ocular reflexes, presumably through direct neural connections between the vestibular nuclei and emotional processing areas of the brain. However, the effects of anxiety, fear and arousal on balance-relevant vestibular reflexes are currently unknown. The purpose of this study was to manipulate standing height to determine whether anxiety and fear can modulate the direct relationship between vestibular signals and balance reflexes during stance. Stochastic vestibular stimulation (SVS; 2-25 Hz) was used to evoke ground reaction forces (GRF) while subjects stood in both LOW and HIGH surface height conditions. Two separate experiments were conducted to investigate the SVS-GRF relationship, in terms of coupling (coherence and cumulant density) and gain, in the medio-lateral (ML) and antero-posterior (AP) directions. The short- and medium-latency cumulant density peaks were both significantly increased in the ML and AP directions when standing in HIGH, compared to LOW, conditions. Likewise, coherence was statistically greater between 4.3 Hz and 6.7 Hz in the ML, and between 5.5 and 17.7 Hz in the AP direction. When standing in the HIGH condition, the gain of the SVS-GRF relationship was increased 81% in the ML direction, and 231% in the AP direction. The significant increases in coupling and gain observed in both experiments demonstrate that vestibular-evoked balance responses are augmented in states of height-induced postural threat. These data support the possibility that fear or anxiety-mediated changes to balance control are affected by altered central processing of vestibular information.
Collapse
Affiliation(s)
- Brian C Horslen
- School of Kinesiology, University of British Columbia, Vancouver, Canada
| | | | - J Timothy Inglis
- School of Kinesiology, University of British Columbia, Vancouver, Canada International Collaboration for Repair Discoveries, University of British Columbia, Vancouver, Canada Brain Research Centre, University of British Columbia, Vancouver, Canada
| | - Jean-Sébastien Blouin
- School of Kinesiology, University of British Columbia, Vancouver, Canada Brain Research Centre, University of British Columbia, Vancouver, Canada The Institute for Computing, Information and Cognitive Systems, University of British Columbia, Vancouver, Canada
| | - Mark G Carpenter
- School of Kinesiology, University of British Columbia, Vancouver, Canada International Collaboration for Repair Discoveries, University of British Columbia, Vancouver, Canada Brain Research Centre, University of British Columbia, Vancouver, Canada
| |
Collapse
|
41
|
Seya Y, Tsuji T, Shinoda H. Effect of depth order on linear vection with optical flows. Iperception 2014; 5:630-40. [PMID: 25926971 PMCID: PMC4411986 DOI: 10.1068/i0671] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2014] [Revised: 11/07/2014] [Indexed: 11/16/2022] Open
Abstract
In the present study, the effects of depth order on forward and backward vection were examined using optical flows simulating motion in depth (i.e., approaching or receding). In an experiment, space extending 10 or 20 m in depth was simulated, and the space was divided into foreground and background spaces. In each space, a random-dot pattern was presented and the binocular disparity, size, and velocity of each dot were continuously manipulated in a way consistent with the depth being simulated. Participants reported whether they perceived vection. Latency, total duration (i.e., the amount of time that participants reported perceiving vection during a 60-s presentation), and strong-vection duration (i.e., the amount of time that participants reported perceiving strong vection) were measured. The results indicated that, even though the dots making up the optical flow were much smaller and slower moving in the background space than in the foreground space, vection was strongly dependent on flow motion in the background space. This supports the idea that the perceptual system uses background stimulus motion as a reliable cue for self-motion perception.
Collapse
Affiliation(s)
- Yasuhiro Seya
- Department of Human and Computer Intelligence, Ritsumeikan University, Kusatsu, Shiga, Japan; e-mail:
| | - Takayuki Tsuji
- Graduate School of Information Science and Engineering, Ritsumeikan University, Kusatsu, Shiga, Japan; e-mail:
| | - Hiroyuki Shinoda
- Department of Human and Computer Intelligence, Ritsumeikan University, Kusatsu, Shiga, Japan; e-mail:
| |
Collapse
|
42
|
Ihaya K, Seno T, Yamada Y. Più mosso: Fast self-motion makes cyclic action faster in virtual reality. REVISTA LATINOAMERICANA DE PSICOLOGIA 2014. [DOI: 10.1016/s0120-0534(14)70006-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
|
43
|
Modulation of visually evoked postural responses by contextual visual, haptic and auditory information: a 'virtual reality check'. PLoS One 2013; 8:e67651. [PMID: 23840760 PMCID: PMC3695920 DOI: 10.1371/journal.pone.0067651] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2013] [Accepted: 05/22/2013] [Indexed: 11/19/2022] Open
Abstract
Externally generated visual motion signals can cause the illusion of self-motion in space (vection) and corresponding visually evoked postural responses (VEPR). These VEPRs are not simple responses to optokinetic stimulation, but are modulated by the configuration of the environment. The aim of this paper is to explore what factors modulate VEPRs in a high quality virtual reality (VR) environment where real and virtual foreground objects served as static visual, auditory and haptic reference points. Data from four experiments on visually evoked postural responses show that: 1) visually evoked postural sway in the lateral direction is modulated by the presence of static anchor points that can be haptic, visual and auditory reference signals; 2) real objects and their matching virtual reality representations as visual anchors have different effects on postural sway; 3) visual motion in the anterior-posterior plane induces robust postural responses that are not modulated by the presence of reference signals or the reality of objects that can serve as visual anchors in the scene. We conclude that automatic postural responses for laterally moving visual stimuli are strongly influenced by the configuration and interpretation of the environment and draw on multisensory representations. Different postural responses were observed for real and virtual visual reference objects. On the basis that automatic visually evoked postural responses in high fidelity virtual environments should mimic those seen in real situations we propose to use the observed effect as a robust objective test for presence and fidelity in VR.
Collapse
|
44
|
Slaboda JC, Keshner EA. Reorientation to vertical modulated by combined support surface tilt and virtual visual flow in healthy elders and adults with stroke. J Neurol 2012; 259:2664-72. [PMID: 22743790 DOI: 10.1007/s00415-012-6566-7] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2012] [Revised: 05/10/2012] [Accepted: 05/18/2012] [Indexed: 01/16/2023]
Abstract
We explored how changes in visual attention impacted postural motor performance in healthy elders and adults post-stroke within a virtual reality environment, including when vestibular information was not perceptible. Visual dependence in 13 healthy (50-80 years) and 13 adults post-stroke (49-70 years) was assessed with a rod-and-frame task. Three degree support surface dorsiflexion tilts at 30°/s were combined with 30° and 45°/s continuous pitch rotations of the visual environment. The support surface remained tilted for 30 s followed by a 0.1°/s return to neutral during continued visual field rotation. Body displacement and ankle muscle responses were recorded, and wavelet transforms calculated. Muscle frequencies and kinematic measures were examined with functional principal component analysis, and weights compared through mixed model repeated measures ANOVA. Both populations exhibited increased backward sway with pitch upward visual field motion; adults post-stroke produced significantly larger muscle responses. Lateral sway was most regulated when visual flow velocity matched platform velocity. Visual flow summed with direction of support surface instability and visually dependent individuals produced more controlled lateral sway when viewing a dynamic visual field. Provoking postural instability within a dynamic visual flow field could serve as a training tool for postural stabilizing actions, particularly when visual dependence is exhibited.
Collapse
Affiliation(s)
- Jill C Slaboda
- Department of Physical Therapy, College of Allied Health Sciences, University of Nevada Las Vegas, 4505 S. Maryland Parkway, Las Vegas, NV 89154-3029, USA.
| | | |
Collapse
|
45
|
Bringoux L, Lepecq JC, Danion F. Does visually induced self-motion affect grip force when holding an object? J Neurophysiol 2012; 108:1685-94. [PMID: 22723677 DOI: 10.1152/jn.00407.2012] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Accurate control of grip force during object manipulation is necessary to prevent the object from slipping, especially to compensate for the action of gravitational and inertial forces resulting from hand/object motion. The goal of the current study was to assess whether the control of grip force was influenced by visually induced self-motion (i.e., vection), which would normally be accompanied by changes in object load. The main task involved holding a 400-g object between the thumb and the index finger while being seated within a virtual immersive environment that simulated the vertical motion of an elevator across floors. Different visual motions were tested, including oscillatory (0.21 Hz) and constant-speed displacements of the virtual scene. Different arm-loading conditions were also tested: with or without the hand-held object and with or without oscillatory arm motion (0.9 Hz). At the perceptual level, ratings from participants showed that both oscillatory and constant-speed motion of the elevator rapidly induced a long-lasting sensation of self-motion. At the sensorimotor level, vection compellingness altered arm movement control. Spectral analyses revealed that arm motion was entrained by the oscillatory motion of the elevator. However, we found no evidence that grip force used to hold the object was visually affected. Specifically, spectral analyses revealed no component in grip force that would mirror the virtual change in object load associated with the oscillatory motion of the elevator, thereby allowing the grip-to-load force coupling to remain unaffected. Altogether, our findings show that the neural mechanisms underlying vection interfere with arm movement control but do not interfere with the delicate modulation of grip force. More generally, those results provide evidence that the strength of the coupling between the sensorimotor system and the perceptual level can be modulated depending on the effector.
Collapse
Affiliation(s)
- Lionel Bringoux
- Institute of Movement Sciences, Aix-Marseille University and Centre National de la Recherche Scientifique, Marseille, France
| | | | | |
Collapse
|
46
|
Visual dependence and BPPV. J Neurol 2011; 259:1117-24. [PMID: 22113702 DOI: 10.1007/s00415-011-6311-7] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2011] [Revised: 10/29/2011] [Accepted: 10/30/2011] [Indexed: 10/15/2022]
Abstract
The increased visual dependence noted in some vestibular patients may be secondary to their vertigo. We examine whether a single, brief vertigo attack, such as in benign paroxysmal positional vertigo (BPPV), modifies visual dependency. Visual dependency was measured before and after the Hallpike manoeuvre with (a) the Rod and Frame and the Rod and Disc techniques whilst seated and (b) the postural sway induced by visual roll-motion stimulation. Three subject groups were studied: 20 patients with BPPV (history and positive Hallpike manoeuvre; PosH group), 20 control patients (history of BPPV but negative Hallpike manoeuvre; NegH group) and 20 normal controls. Our findings show that while both patient groups showed enhanced visual dependency, the PosH and the normal control group decreased visual dependency on repetition of the visual tasks after the Hallpike manoeuvre. NegH patients differed from PosH patients in that their high visual dependency did not diminish on repetition of the visual stimuli; they scored higher on the situational characteristic questionnaire ('visual vertigo' symptoms) and showed higher incidence of migraine. We conclude that long term vestibular symptoms increase visual dependence but a single BPPV attack does not increase it further. Repetitive visual motion stimulation induces adaptation in visual dependence in peripheral vestibular disorders such as BPPV. A positional form of vestibular migraine may underlie the symptoms of some patients with a history of BPPV but negative Hallpike manoeuvre. The finding that they have non adaptable increased visual dependency may explain visuo-vestibular symptoms in this group and, perhaps more widely, in patients with migraine.
Collapse
|
47
|
Slaboda JC, Lauer RT, Keshner EA. Continuous visual field motion impacts the postural responses of older and younger women during and after support surface tilt. Exp Brain Res 2011; 211:87-96. [PMID: 21479659 DOI: 10.1007/s00221-011-2655-6] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2010] [Accepted: 03/23/2011] [Indexed: 10/18/2022]
Abstract
The effect of continuous visual flow on the ability to regain and maintain postural orientation was examined. Fourteen young (20-39 years old) and 14 older women (60-79 years old) stood quietly during 3° (30°/s) dorsiflexion tilt of the support surface combined with 30° and 45°/s upward or downward pitch rotations of the visual field. The support surface was held tilted for 30 s and then returned to neutral over a 30-s period while the visual field continued to rotate. Segmental displacement and bilateral tibialis anterior and gastrocnemius muscle EMG responses were recorded. Continuous wavelet transforms were calculated for each muscle EMG response. An instantaneous mean frequency curve (IMNF) of muscle activity, center of mass (COM), center of pressure (COP), and angular excursion at the hip and ankle were used in a functional principal component analysis (fPCA). Functional component weights were calculated and compared with mixed model repeated measures ANOVAs. The fPCA revealed greatest mathematical differences in COM and COP responses between groups or conditions during the period that the platform transitioned from the sustained tilt to a return to neutral position. Muscle EMG responses differed most in the period following support surface tilt indicating that muscle activity increased to support stabilization against the visual flow. Older women exhibited significantly larger COM and COP responses in the direction of visual field motion and less muscle modulation when the platform returned to neutral than younger women. Results on a Rod and Frame test indicated that older women were significantly more visually dependent than the younger women. We concluded that a stiffer body combined with heightened visual sensitivity in older women critically interferes with their ability to counteract posturally destabilizing environments.
Collapse
Affiliation(s)
- Jill C Slaboda
- Department of Physical Therapy, College of Health Professions and Social Work, Temple University, Philadelphia, PA 19140, USA.
| | | | | |
Collapse
|
48
|
Chagdes JR, Rietdyk S, Haddad JM, Zelaznik HN, Raman A, Rhea CK, Silver TA. Multiple timescales in postural dynamics associated with vision and a secondary task are revealed by wavelet analysis. Exp Brain Res 2009; 197:297-310. [PMID: 19578840 DOI: 10.1007/s00221-009-1915-1] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2008] [Accepted: 06/17/2009] [Indexed: 10/20/2022]
Abstract
Discrete wavelet analysis is used to resolve the center of pressure time series data into several timescale components, providing new insights into postural control. Healthy young and elderly participants stood quietly with their eyes open or closed and either performed a secondary task or stood quietly. Without vision, both younger and older participants had reduced energy in the long timescales, supporting the concept that vision is used to control low frequency postural sway. Furthermore, energy was increased at timescales corresponding to closed-loop (somatosensory and vestibular) and open-loop mechanisms, consistent with the idea of a shift from visual control to other control mechanisms. However, a relatively greater increase was observed for older adults. With a secondary task a similar pattern was observed-increased energy at the short and moderate timescales, decreased energy at long timescales. The possibility of a common strategy-at the timescale level-in response to postural perturbations is considered.
Collapse
Affiliation(s)
- James R Chagdes
- School of Mechanical Engineering, Purdue University, West Lafayette, IN, 47907-2038, USA.
| | | | | | | | | | | | | |
Collapse
|
49
|
Ocular versus extraocular control of posture and equilibrium. Neurophysiol Clin 2008; 38:391-8. [DOI: 10.1016/j.neucli.2008.09.007] [Citation(s) in RCA: 74] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2008] [Accepted: 09/17/2008] [Indexed: 11/19/2022] Open
|