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INTRODUCTION: It has been reported that vibrating electromechanical tactile stimulation on the torso overrides the vestibular sensation of rotation. The purpose of this study is to further examine the influence of tactile cues on real and apparent sensations of self-rotation and corresponding vestibular nystagmus during passive yaw rotation. METHOD: There were 15 healthy subjects (12 men and 3 women, 31 to 49 yr) who were subjected to clockwise yaw rotation at a constant velocity of 120 degrees. s(-1). A tactile vest using electromechanical tactors (8 columns x 3 rows) was activated either in the clockwise or counterclockwise direction in a randomized design. The sequential activation of the tactors around the body matched the velocity of chair rotation. Eye movements were monitored using infrared eye tracking. Since it is difficult to control for mental set (alertness and imagined target distance) during eye tracking, in addition to paying attention to the apparent sensation of self-motion, the sensation of rotation and the induced vestibular nystagmus were investigated separately. RESULTS: ANOVA failed to reveal any significant effect. Our results suggested that tactile cueing did not enhance or suppress the subjective sensation of rotation during actual rotation, nor did it enhance or suppress the false sensation of rotation experienced. Also, tactile cueing had no effect on the gain and time constant of the induced per-rotation and post-rotation nystagmus with repeated exposures. CONCLUSION: It appears that tactile cueing delivered by a tactile garment provides a sense of direction, but it does not affect any concomitant vestibular responses. 相似文献
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The effects of vestibular stimulation on head and trunk movements were investigated during human walking (4.0 km/h). Vestibular stimulation was produced by irrigating an external auditory meatus with 4 °C ice water for 10 s. Using a 3-D motion analysis system, the linear (medial/lateral and vertical) translations and angular (yaw, pitch and roll) rotations were determined at the head, thorax, pelvis, knee, and foot. After caloric stimulation, waking trajectory deviated toward the stimulated side during dizziness. In addition, the amplitude of medial/lateral (M/L) linear translation and yaw rotation were significantly increased by caloric stimulation, especially at the head and thorax, whereas changes in vertical translation and pitch and roll rotations were not significant. The compensatory coordination (i.e., the yaw rotation to oppose the M/L linear translation) of the head was precisely maintained both before and after caloric stimulations, but it was decreased at the thorax and pelvis after stimulation. Our results suggested that vestibular sensory information, probably via the horizontal semicircular canals, contributes predominantly to the regulation of dynamic head and trunk movements in the M/L direction. 相似文献
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适当体位旋转训练对人体前庭功能的影响 总被引:2,自引:0,他引:2
目的 探讨通过适当体位旋转训练的方法 ,提高人体前庭系统耐受科里奥利加速度能力。 方法 将第一次转椅检查前庭自主神经反应Ⅰ度和Ⅱ度者 ,随机分为训练 1个月组、训练 3个月组和对照组 ,训练组人体前屈 1 2 0° ,右手从左臂下方绕过拉住左耳廓 ,头向左侧偏曲呈 6 0°,两腿并拢伸直 ,左手指向脚尖 ,原地向左转 5圈后迅速直立 ,每天 1次。 结果 转椅复查 ,对照组效果较其它两组差 ,训练 1个月组与训练 3个月组效果差别不大。 结论 适当体位旋转训练可提高人体前庭系统耐受科里奥利加速度能力 ,但提高是有限度的 相似文献
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Human control performance in nulling perceived tilt angles was investigated for combinations of pseduo-random vestibular disturbances and different waveforms of low frequency wide visual field motions. For both roll and pitch axes, subjects tilted the trainer in which they were seated in the direction of field rotation. This visual bias was much stronger for pitch backwards with upward field rotation. Frequency response analysis showed the dominance of visual cues at low frequencies (below 0.06 Hz) and the reliance on vestibular information in the high frequency range for both axes. Models suggest that operator balancing responses at high frequencies are mainly processed by the semicircular canals rather than the otolith organs. The results also suggest that the subject tends to rely less on the otolith organs for pitch perception than for roll. 相似文献
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目的:观察一些抗运动病药物对前庭受刺激时兔脑电功率谱的影响。方法:前庭刺激为持续45分钟的正弦旋转,峰角速度60°/s,正弦周期4秒。结果与结论:旋转刺激引起生理盐水对照组动物大脑皮质抑制。哌醋甲酯可逆转这种作用,支持Kohl提出的该药抗运动病的作用假说。东莨菪碱加深了前庭刺激对大脑皮质的抑制。而山莨菪碱可阻断前庭刺激对大脑皮质的抑制,且文献报道其外周副作用亦小。因此山莨菪碱用于抗运动病比东莨菪碱对机体有利。 相似文献
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G I Gorgiladze G I Samarin S N Rusanov 《Kosmicheskaia biologiia i aviakosmicheskaia meditsina》1983,17(2):48-52
The development of illusionary movements and oscillations of the total body mass center in response to labyrinthine stimulation by ascending and descending current was investigated in 37 healthy test subjects. The stimulation of each labyrinth separately or both labyrinths by the current of opposite direction caused illusionary sensations of tilts, turns and tumbles in various planes. When the test subjects were on the stabilographic platform, their total body mass center shifted toward the anode. Simultaneous stimulation of both labyrinths by the current of one direction produced qualitatively new reactions, such as illusionary movement and displacement of the mass center toward the sagittal plane. 相似文献
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van Schooten KS Sloot LH Bruijn SM Kingma H Meijer OG Pijnappels M van Dieën JH 《Gait & posture》2011,33(4):656-660
For targeted prevention of falls, it is necessary to identify individuals with balance impairments. To test the sensitivity of measures of variability, local stability and orbital stability of trunk kinematics to balance impairments during gait, we used galvanic vestibular stimulation (GVS) to impair balance in 12 young adults while walking on a treadmill at different speeds. Inertial sensors were used to measure trunk accelerations, from which variability in the medio-lateral direction and local and orbital stability were calculated. The short-term Lyapunov exponent and variability reflected the destabilizing effect of GVS, while the long-term Lyapunov exponent and Floquet multipliers suggested increased stability. Therefore, we concluded that only short-term Lyapunov exponents and variability can be used to asses stability of gait. In addition, to investigate the feasibility of using these measures in screening for fall risk, the presence or absence of GVS was predicted with variability and the short-term Lyapunov exponent. Predictions were good at all walking speeds, but best at preferred walking speed, with a correct classification in 83.3% of the cases. 相似文献
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目的通过比较不同的声刺激模式对前庭诱发肌性电位的影响,确定前庭诱发肌性电位检测的最佳声刺激模式。方法9名健康志愿者被随机分成三组,按3×3拉丁方析因设计,对3个不同频率(250、500、750Hz)、3个不同刺激重复率(5、7、10Hz)、3个不同平台时间(2、5、10ms)的短纯音诱发的前庭诱发肌性电位(VEMP)进行测试,每人以随机次序进行9次测试。比较前庭诱发肌性电位的诱发率、潜伏期、波间幅度及双侧幅度不对称比。结果不同短纯音频率对双侧VEMP的潜伏期及幅度及双侧幅度不对称比均有影响,按500、250、750Hz顺序,双侧P13/N23潜伏期依次增加}双侧P13/N23幅度依次减少;双侧幅度不对称比依次增加。500Hz短纯音刺激时双侧幅度最大且双侧幅度不对称比最小;5、7、10Hz3种不同刺激重复率对双侧VEMP的潜伏期、波间幅度及双侧幅度不对称比均无影响,2、5、10ms 3种短纯音不同平台持续时间对双侧VEMP的幅度有影响,按10、5、2ms顺序,双侧VEMP的幅度逐渐增加。而3种短纯音不同平台持续时间对双侧VEMP的潜伏期、双侧幅度不对称比未有明显影响。结论VEMP的最佳声刺激参数为平台时间2ms、频率500Hz、刺激重复率5Hz。 相似文献
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Marcelli V Esposito F Aragri A Furia T Riccardi P Tosetti M Biagi L Marciano E Di Salle F 《European journal of radiology》2009,70(2):312-316
Processing of vestibular information at the cortical and subcortical level is essential for head and body orientation in space and self-motion perception, but little is known about the neural dynamics of the brain regions of the vestibular system involved in this task. Neuroimaging studies using both galvanic and caloric stimulation have shown that several distinct cortical and subcortical structures can be activated during vestibular information processing. The insular cortex has been often targeted and presented as the central hub of the vestibular cortical system. Since very short pulses of cold water ear irrigation can generate a strong and prolonged vestibular response and a nystagmus, we explored the effects of this type of caloric stimulation for assessing the blood-oxygen-level-dependent (BOLD) dynamics of neural vestibular processing in a whole-brain event-related functional magnetic resonance imaging (fMRI) experiment. We evaluated the spatial layout and the temporal dynamics of the activated cortical and subcortical regions in time-locking with the instant of injection and were able to extract a robust pattern of neural activity involving the contra-lateral insular cortex, the thalamus, the brainstem and the cerebellum. No significant correlation with the temporal envelope of the nystagmus was found. The temporal analysis of the activation profiles highlighted a significantly longer duration of the evoked BOLD activity in the brainstem compared to the insular cortex suggesting a functional de-coupling between cortical and subcortical activity during the vestibular response. 相似文献
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BACKGROUND: It has been known since 1953 that pre-exposure to less than +1 Gz will reduce subsequent +Gz-tolerance. With few exceptions, during operational flying, the transition from hypogravity to hypergravity involves roll as well as pitch rotation. We examined the effect of roll vs. pitch rotation while undergoing transition from hypogravity to +1 Gz on a tilt table. METHODS: Twelve subjects (28-47 yr old) were rotated at 45 degrees x s(-1) from head-up (HU) at 15 degrees relative to gravitational vertical to 135 degrees head-down (HD) and back to the HU position after different HD dwell times. HD dwell times were set at 7, 15, and 30 s. The subject was rotated about the interaural axis (pitch) and about the naso-occipital axis (roll). Both the HD dwell times and axes of rotation were randomized within and across subjects. BP and heart rate were recorded during the HU-HD-HU maneuver. RESULTS: Analysis of variance, repeated measure design revealed that the rate and magnitude of BP decrease induced by the HD to HU maneuver is significantly higher (p < 0.01) in roll than in pitch during all HD dwell times. The decrease of BP at 7s is significantly (p < 0.01) higher than at 15s and 30s. Heart rate increases significantly higher (p < 0.01) in pitch than in roll at 7s-dwell time. CONCLUSION: Our results suggest that the compensatory mechanism to orthostatic stress is more efficient in response to pitch than roll rotation. This is reflected from the findings that the mean magnitude of OH (orthostatic hypotension) and the rate of BP decrease induced by the HD-HU maneuver is significantly greater in roll rotation than pitch rotation. The mean HR increase post HD-HU rotation is significantly higher in the pitch than the roll rotation. The significant rate of BP decrease during HD-HU roll rotation could have important implications for maintaining G-tolerance and spatial orientation during subsequent exposure to hypergravity. 相似文献
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Galvanic vestibular stimulation (GVS) applied between the mastoids during quiet standing elicits postural sway. The aim of this study was to characterize the postural sway response to continuous sinusoidal GVS across various stimulus frequencies and amplitudes. Binaural bipolar sinusoidal GVS was applied to the skin overlying the mastoid processes of 10 subjects while they stood on a force plate with eyes closed. The position of the center of pressure (COP) at the feet was recorded from a forceplate, while the head displacement was measured with a magnetic position tracking system. The stimulus conditions included four frequencies (0.1, 0.25, 0.45, and 1.1 Hz) and five peak amplitudes (0.05, 0.1, 0.25, 0.5, and 1.0 mA). Each subject experienced one trial at each amplitude-frequency pair. Additionally, each subject underwent three trials in which a dual-frequency stimulus (0.1 plus 0.45 Hz at a peak of 0.5 mA each) was presented. The stimuli elicited sway in the frontal plane in all subjects, as evidenced by changes in the displacement of the COP and head. Sway magnitude decreased with increasing stimulus frequency and increased with increasing stimulus amplitude. However, the response magnitude saturated at higher stimulus amplitudes. Phase lag increased with increasing stimulus frequency. The response to the dual-frequency stimulus was reduced at 0.1 Hz and nearly equal at 0.45 Hz in comparison with the single-frequency responses. This study suggests that the postural sway response is nonlinear due to saturation and violation of the principle of superposition. 相似文献
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Kenefick RW Hazzard MP Mahood NV Castellani JW 《Medicine and science in sports and exercise》2004,36(9):1528-1534
PURPOSE: The purpose of this study was to 1) determine the effect of hypohydration (HYPO) on thirst sensations during moderate exercise in the cold and 2) determine a possible mechanism for a cold-induced decline in thirst. METHODS: In the first phase of the study, eight males walked on four occasions, in T-shirts, shorts, and shoes, at 50% VO2max, for 60 min in either a 4 degrees C (cold) or 27 degrees C (temperate) environment in a state of HYPO or euhydration (EU). In the second phase, nine males in states of EU or HYPO randomly performed four trials consisting of 30 min standing at 27 degrees C, followed by 30 min of standing and 30 min of treadmill exercise at 50% of VO2max, in either 4 degrees C or 27 degrees C air. RESULTS: In phase 1, thirst sensations were lower throughout 60 min of exercise (P < 0.05) in both HYPO and EU conditions during the cold trials. In phase 2, despite elevated plasma osmolality (P < 0.05), perception of thirst and plasma arginine vasopressin [AVP] similarly decreased (P < 0.05) after 30-min standing rest and 30-min exercise in the HYPO-cold trial, compared with the HYPO-temperate, EU-cold, and EU-temperate trials. CONCLUSIONS: When either euhydrated or hypohydrated, cold exposure attenuated thirst by up to 40% at rest and during moderate-intensity exercise. The attenuated thirst when hypohydrated during cold exposure was associated with lower plasma [AVP] despite an elevated plasma osmolality. This decline in thirst and AVP in the cold may be the result of peripheral vasoconstriction, mediating an increase in central blood volume and stimulation of central volume receptors. 相似文献
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