Impacts of Rotation Axis and Frequency on Vestibular Perceptual Thresholds

2022 ◽  
pp. 1-29
Author(s):  
Andrew R. Wagner ◽  
Megan J. Kobel ◽  
Daniel M. Merfeld
Keyword(s):  
Multisensory Integration ◽  
Rotation Axis ◽  
Semicircular Canals ◽  
Rotation Velocity ◽  
Pass Filter ◽  
Motion Cues ◽  
Left Posterior ◽  
Rotation Plane ◽  
Self Motion ◽  
Lower Frequencies

Abstract In an effort to characterize the factors influencing the perception of self-motion rotational cues, vestibular self-motion perceptual thresholds were measured in 14 subjects for rotations in the roll and pitch planes, as well as in the planes aligned with the anatomic orientation of the vertical semicircular canals (i.e., left anterior, right posterior; LARP, and right anterior, left posterior; RALP). To determine the multisensory influence of concurrent otolith cues, within each plane of motion, thresholds were measured at four discrete frequencies for rotations about earth-horizontal (i.e., tilts; EH) and earth-vertical axes (i.e., head positioned in the plane of the rotation; EV). We found that the perception of rotations, stimulating primarily the vertical canals, was consistent with the behavior of a high-pass filter for all planes of motion, with velocity thresholds increasing at lower frequencies of rotation. In contrast, tilt (i.e, EH rotation) velocity thresholds, stimulating both the canals and otoliths (i.e., multisensory integration), decreased at lower frequencies and were significantly lower than earth-vertical rotation thresholds at each frequency below 2 Hz. These data suggest that multisensory integration of otolithic gravity cues with semicircular canal rotation cues enhances perceptual precision for tilt motions at frequencies below 2 Hz. We also showed that rotation thresholds, at least partially, were dependent on the orientation of the rotation plane relative to the anatomical alignment of the vertical canals. Collectively these data provide the first comprehensive report of how frequency and axis of rotation influence perception of rotational self-motion cues stimulating the vertical canals.

Reflections of Efferent Activity in Rotational Responses of Chinchilla Vestibular Afferents

2002 ◽  
Vol 88 (3) ◽  
pp. 1234-1244 ◽  
Author(s):  
Meir Plotnik ◽  
Vladimir Marlinski ◽  
Jay M. Goldberg
Keyword(s):  
Rotation Axis ◽  
Semicircular Canals ◽  
Horizontal Canal ◽  
Efferent System ◽  
Type Iii ◽  
Complete Section ◽  
Viiith Nerve ◽  
Rotation Plane ◽  
Excitatory Responses ◽  
Stimulation Of

To study presumed efferent-mediated responses, we determined if afferents responded to head rotations that stimulated semicircular canals other than the organ being innervated. To minimize stimulation of an afferent's own canal, its plane was placed nearly orthogonal to the rotation plane. Otolith units were tested in a horizontal head position with the ear placed near the rotation axis to minimize linear forces. Under these circumstances, angular-velocity trapezoids (2-s ramps, 2-s plateau) evoked excitatory responses for both rotation directions. These type III responses were considerably larger in decerebrate than in anesthetized preparations. In addition to their being exclusively excitatory, the responses resembled those obtained with electrical stimulation of efferent pathways in including per-stimulus and more prolonged post-stimulus components and in being larger in irregularly discharging than in regularly discharging units. Responses, which were not seen for rotations <80°/s, grew as velocity increased between 80 and 500°/s but were seldom larger than 20 spikes/s. Complete section of the VIIIth nerve abolished type III responses, leaving conventional afferent responses intact. To study the separate contributions of canals on the two sides, responses were compared when the labyrinths were intact and when the ipsilateral or contralateral horizontal canal was mechanically inactivated. Both sides contributed to the efferent-mediated responses. That afferents could be influenced from the contralateral labyrinth was confirmed with the use of unilateral galvanic currents. Following inactivation, excitatory responses were produced by rotations exciting or inhibiting the intact horizontal canal with the responses resulting from excitatory rotations being much larger. Such a response asymmetry is consistent with a semicircular-canal origin for the type III responses. A similar asymmetry was seen in the post-stimulus responses to contralateral cathodal (excitatory) and anodal (inhibitory) galvanic currents. We conclude that the efferent system receives a sufficiently powerful vestibular input from both the ipsilateral and contralateral labyrinths to affect afferent discharge.

scholarly journals Rotational Self-motion Cues Improve Spatial Learning when Teleporting in Virtual Environments

2020 ◽  
Author(s):  
Alex F. Lim ◽  
Jonathan W. Kelly ◽  
Nathan C. Sepich ◽  
Lucia A. Cherep ◽  
Grace C. Freed ◽  
...  
Keyword(s):  
Virtual Environments ◽  
Spatial Learning ◽  
Motion Cues ◽  
Self Motion

scholarly journals Sensorimotor impairment from a new analog of spaceflight-altered neurovestibular cues

2020 ◽  
Vol 123 (1) ◽  
pp. 209-223
Author(s):  
Jordan B. Dixon ◽  
Torin K. Clark
Keyword(s):  
Head Tilt ◽  
Semicircular Canals ◽  
Control Groups ◽  
Head Restraint ◽  
The Subject ◽  
Sensorimotor Impairment ◽  
Self Motion ◽  
Future Work ◽  
Extended Exposure ◽  
Sensorimotor Performance

Exposure to microgravity during spaceflight causes central reinterpretations of orientation sensory cues in astronauts, leading to sensorimotor impairment upon return to Earth. Currently there is no ground-based analog for the neurovestibular system relevant to spaceflight. We propose such an analog, which we term the “wheelchair head-immobilization paradigm” (WHIP). Subjects lie on their side on a bed fixed to a modified electric wheelchair, with their head restrained by a custom facemask. WHIP prevents any head tilt relative to gravity, which normally produces coupled stimulation to the otoliths and semicircular canals, but does not occur in microgravity. Decoupled stimulation is produced through translation and rotation on the wheelchair by the subject using a joystick. Following 12 h of WHIP exposure, subjects systematically felt illusory sensations of self-motion when making head tilts and had significant decrements in balance and locomotion function using tasks similar to those assessed in astronauts postspaceflight. These effects were not observed in our control groups without head restraint, suggesting the altered neurovestibular stimulation patterns experienced in WHIP lead to relevant central reinterpretations. We conclude by discussing the findings in light of postspaceflight sensorimotor impairment, WHIP’s uses beyond a spaceflight analog, limitations, and future work. NEW & NOTEWORTHY We propose, implement, and demonstrate the feasibility of a new analog for spaceflight-altered neurovestibular stimulation. Following extended exposure to the analog, we found subjects reported illusory self-motion perception. Furthermore, they demonstrated decrements in balance and locomotion, using tasks similar to those used to assess astronaut sensorimotor performance postspaceflight.

scholarly journals Active Locomotion Increases Peak Firing Rates of Anterodorsal Thalamic Head Direction Cells

2001 ◽  
Vol 86 (2) ◽  
pp. 692-702 ◽  
Author(s):  
Michaël B. Zugaro ◽  
Eiichi Tabuchi ◽  
Céline Fouquier ◽  
Alain Berthoz ◽  
Sidney I. Wiener
Keyword(s):  
Visual Cues ◽  
Head Direction ◽  
Small Reservoir ◽  
Motion Cues ◽  
Preferred Direction ◽  
State Dependent ◽  
Command Signals ◽  
Rats And Mice ◽  
Foraging Task ◽  
Self Motion

Head direction (HD) cells discharge selectively in macaques, rats, and mice when they orient their head in a specific (“preferred”) direction. Preferred directions are influenced by visual cues as well as idiothetic self-motion cues derived from vestibular, proprioceptive, motor efferent copy, and command signals. To distinguish the relative importance of active locomotor signals, we compared HD cell response properties in 49 anterodorsal thalamic HD cells of six male Long-Evans rats during active displacements in a foraging task as well as during passive rotations. Since thalamic HD cells typically stop firing if the animals are tightly restrained, the rats were trained to remain immobile while drinking water distributed at intervals from a small reservoir at the center of a rotatable platform. The platform was rotated in a clockwise/counterclockwise oscillation to record directional responses in the stationary animals while the surrounding environmental cues remained stable. The peak rate of directional firing decreased by 27% on average during passive rotations ( r 2 = 0.73, P< 0.001). Individual cells recorded in sequential sessions ( n = 8) reliably showed comparable reductions in peak firing, but simultaneously recorded cells did not necessarily produce identical responses. All of the HD cells maintained the same preferred directions during passive rotations. These results are consistent with the hypothesis that the level of locomotor activity provides a state-dependent modulation of the response magnitude of AD HD cells. This could result from diffusely projecting neuromodulatory systems associated with motor state.

scholarly journals Population Coding of Self-Motion: Applying Bayesian Analysis to a Population of Visual Interneurons in the Fly

2005 ◽  
Vol 94 (3) ◽  
pp. 2182-2194 ◽  
Author(s):  
Katja Karmeier ◽  
Holger G. Krapp ◽  
Martin Egelhaaf
Keyword(s):  
Bayesian Analysis ◽  
Rotation Axis ◽  
Sensory Information ◽  
Population Coding ◽  
Calliphora Vicina ◽  
Integration Time ◽  
Noise Correlation ◽  
Neuronal Populations ◽  
Response Onset ◽  
Self Motion

Coding of sensory information often involves the activity of neuronal populations. We demonstrate how the accuracy of a population code depends on integration time, the size of the population, and noise correlation between the participating neurons. The population we study consists of 10 identified visual interneurons in the blowfly Calliphora vicina involved in optic flow processing. These neurons are assumed to encode the animal's head or body rotations around horizontal axes by means of graded potential changes. From electrophysiological experiments we obtain parameters for modeling the neurons' responses. From applying a Bayesian analysis on the modeled population response we draw three major conclusions. First, integration of neuronal activities over a time period of only 5 ms after response onset is sufficient to decode accurately the rotation axis. Second, noise correlation between neurons has only little impact on the population's performance. And third, although a population of only two neurons would be sufficient to encode any horizontal rotation axis, the population of 10 vertical system neurons is advantageous if the available integration time is short. For the fly, short integration times to decode neuronal responses are important when controlling rapid flight maneuvers.

scholarly journals Convergence of linear acceleration and yaw rotation signals on non-eye movement neurons in the vestibular nucleus of macaques

2018 ◽  
Vol 119 (1) ◽  
pp. 73-83 ◽  
Author(s):  
Shawn D. Newlands ◽  
Ben Abbatematteo ◽  
Min Wei ◽  
Laurel H. Carney ◽  
Hongge Luan
Keyword(s):  
Eye Movement ◽  
Multisensory Integration ◽  
Vestibular Nucleus ◽  
Semicircular Canals ◽  
Linear Acceleration ◽  
Vestibular Nuclei ◽  
Otolith Organs ◽  
Angular Rotation ◽  
Sensory Signals ◽  
Nonlinear Integration

Roughly half of all vestibular nucleus neurons without eye movement sensitivity respond to both angular rotation and linear acceleration. Linear acceleration signals arise from otolith organs, and rotation signals arise from semicircular canals. In the vestibular nerve, these signals are carried by different afferents. Vestibular nucleus neurons represent the first point of convergence for these distinct sensory signals. This study systematically evaluated how rotational and translational signals interact in single neurons in the vestibular nuclei: multisensory integration at the first opportunity for convergence between these two independent vestibular sensory signals. Single-unit recordings were made from the vestibular nuclei of awake macaques during yaw rotation, translation in the horizontal plane, and combinations of rotation and translation at different frequencies. The overall response magnitude of the combined translation and rotation was generally less than the sum of the magnitudes in responses to the stimuli applied independently. However, we found that under conditions in which the peaks of the rotational and translational responses were coincident these signals were approximately additive. With presentation of rotation and translation at different frequencies, rotation was attenuated more than translation, regardless of which was at a higher frequency. These data suggest a nonlinear interaction between these two sensory modalities in the vestibular nuclei, in which coincident peak responses are proportionally stronger than other, off-peak interactions. These results are similar to those reported for other forms of multisensory integration, such as audio-visual integration in the superior colliculus. NEW & NOTEWORTHY This is the first study to systematically explore the interaction of rotational and translational signals in the vestibular nuclei through independent manipulation. The results of this study demonstrate nonlinear integration leading to maximum response amplitude when the timing and direction of peak rotational and translational responses are coincident.

Apparent Depth with Retinal Image Motion of Expansion and Contraction Yoked to Head Movement

Perception ◽  
1998 ◽  
Vol 27 (8) ◽  
pp. 937-949 ◽  
Author(s):  
Takanao Yajima ◽  
Hiroyasu Ujike ◽  
Keiji Uchikawa
Keyword(s):  
Motion Parallax ◽  
Ccd Camera ◽  
Head Movements ◽  
Image Motion ◽  
Apparent Depth ◽  
Motion Cues ◽  
Relative Expansion ◽  
Retinal Image Motion ◽  
Self Motion

The two main questions addressed in this study were (a) what effect does yoking the relative expansion and contraction (EC) of retinal images to forward and backward head movements have on the resultant magnitude and stability of perceived depth, and (b) how does this relative EC image motion interact with the depth cues of motion parallax? Relative EC image motion was produced by moving a small CCD camera toward and away from the stimulus, two random-dot surfaces separated in depth, in synchrony with the observers' forward and backward head movements. Observers viewed the stimuli monocularly, on a helmet-mounted display, while moving their heads at various velocities, including zero velocity. The results showed that (a) the magnitude of perceived depth was smaller with smaller head velocities (<10 cm s−1), including the zero-head-velocity condition, than with a larger velocity (10 cm s−1), and (b) perceived depth, when motion parallax and the EC image motion cues were simultaneously presented, is equal to the greater of the two possible perceived depths produced from either of these two cues alone. The results suggested the role of nonvisual information of self-motion on perceiving depth.

Sensorimotor aspects of high-speed artificial gravity: II. The effect of head position on illusory self motion

2003 ◽  
Vol 12 (5-6) ◽  
pp. 283-289
Author(s):  
Fred W. Mast ◽  
Nathaniel J. Newby ◽  
Laurence R. Young
Keyword(s):  
Healthy Subjects ◽  
Horizontal Plane ◽  
High Speed ◽  
Semicircular Canals ◽  
Vertical Axis ◽  
Head Position ◽  
Artificial Gravity ◽  
Axis Of Rotation ◽  
Self Motion

The effects of cross-coupled stimuli on the semicircular canals are shown to be influenced by the position of the subject's head with respect to gravity and the axis of rotation, but not by the subject's head position relative to the trunk. Seventeen healthy subjects made head yaw movements out of the horizontal plane while lying on a horizontal platform (MIT short radius centrifuge) rotating at 23 rpm about an earth-vertical axis. The subjects reported the magnitude and duration of the illusory pitch or roll sensations elicited by the cross-coupled rotational stimuli acting on the semicircular canals. The results suggest an influence of head position relative to gravity. The magnitude estimation is higher and the sensation decays more slowly when the head's final position is toward nose-up (gravity in the subject's head x-z-plane) compared to when the head is turned toward the side (gravity in the subject's head y-z-plane). The results are discussed with respect to artificial gravity in space and the possible role of pre-adaptation to cross-coupled angular accelerations on earth.

scholarly journals Egocentric and Allocentric Spatial Memory in Mild Cognitive Impairment with Real-World and Virtual Navigation Tasks: A Systematic Review

2021 ◽  
Vol 79 (1) ◽  
pp. 95-116
Author(s):  
Cosimo Tuena ◽  
Valentina Mancuso ◽  
Chiara Stramba-Badiale ◽  
Elisa Pedroli ◽  
Marco Stramba-Badiale ◽  
...  
Keyword(s):  
Systematic Review ◽  
Cognitive Impairment ◽  
Mild Cognitive Impairment ◽  
Spatial Memory ◽  
Real World ◽  
Reference Frames ◽  
Spatial Navigation ◽  
Experimental Studies ◽  
Motion Cues ◽  
Self Motion

Background: Spatial navigation is the ability to estimate one’s position on the basis of environmental and self-motion cues. Spatial memory is the cognitive substrate underlying navigation and relies on two different reference frames: egocentric and allocentric. These spatial frames are prone to decline with aging and impairment is even more pronounced in Alzheimer’s disease (AD) or in mild cognitive impairment (MCI). Objective: To conduct a systematic review of experimental studies investigating which MCI population and tasks are used to evaluate spatial memory and how allocentric and egocentric deficits are impaired in MCI after navigation. Methods: PRISMA and PICO guidelines were applied to carry out the systematic search. Down and Black checklist was used to assess methodological quality. Results: Our results showed that amnestic MCI and AD pathology are the most investigated typologies; both egocentric and allocentric memory are impaired in MCI individuals, and MCI due to AD biomarkers has specific encoding and retrieval impairments; secondly, spatial navigation is principally investigated with the hidden goal task (virtual and real-world version), and among studies involving virtual reality, the privileged setting consists of non-immersive technology; thirdly, despite subtle differences, real-world and virtual versions showed good overlap for the assessment of MCI spatial memory. Conclusion: Considering that MCI is a subclinical entity with potential risk for conversion to dementia, investigating spatial memory deficits with navigation tasks might be crucial to make accurate diagnosis and rehabilitation.

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