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The Future of the Cloud
Published in Marcus K. Weldon, The Future X Network, 2018
Finally, the low-latency and high-bandwidth service delivery capabilities of the global-local cloud will usher in a new wave of innovative augmented reality (AR) applications. To meet human perception requirements today, augmented reality is dependent on on-board processing and local content. The ability to move this processing and content to the cloud makes AR more portable by allowing appropriate content to be presented to users no matter where they are. However, as the AR content becomes more immersive (for example, a video overlay of reality for instructional purposes), the lag between the user’s movements and changes in the AR overlay display become critical in avoiding a poor user experience (including disorientation and nausea). Physiologically, the vestibulo-ocular reflex (VOR) in humans coordinates eye and head movements to stabilize images on the retina. Studies have shown the VOR to be approximately 7 ms. Therefore, to avoid user disorientation, similar latencies must be achieved by AR applications. Localizing resources in the global-local cloud will allow extremely low-latency coordination between the user and AR processing and content, which will in turn enable a nearly imperceptible lag between real and virtual elements. While significant issues exist in this field (not the least of which is a viable unobtrusive display device), enabling AR services to be delivered from the cloud will remove a major obstacle to future innovation.
Tools for Sensor-Based Performance Assessment and Hands-Free Control
Published in Jack M. Winters, Molly Follette Story, Medical Instrumentation, 2006
Compensatory eye movements are also smooth movements, but they compensate for active or passive motion of the head or trunk. The purpose of these movements, also called the vestibulo-ocular reflex (VOR), is to stabilize the retinal image of fixed objects during head motion. Compensatory movements are attributable to stimulation of the semicircular canals due to head turning and stimulation of proprioceptors located in the neck, with a documented “3-neuron arc” for some of the signal, thus enabling a latency for this eye movement system that is very small relative to other types of eye movements (e.g., 20 msec).
Eye Tracking from a Human Factors Perspective
Published in Guy A. Boy, The Handbook of Human-Machine Interaction, 2017
Vestibulo-ocular reflex (VOR) is the process by which eye position is maintained in space during head rotations. The eyes counter-rotate with respect to the head so that fixations can be maintained on a stationary visual scene item. Head movements are sensed by the vestibular apparatus in the inner ear.
Head control and head-trunk coordination as a function of anticipation in sidestepping
Published in Journal of Sports Sciences, 2022
Samuel Zeff, Gillian Weir, Joseph Hamill, Richard van Emmerik
The head is a perceptual platform, providing a foundation for the visual and vestibular systems to function (Hamill et al., 2020). During forward locomotion the head is stabilized in space through angular rotations, in response to both angular and translational perturbations in each plane (Pozzo et al., 1995; 1990; Imai et al., 2001; Hirasaki et al., 1999; Moore et al., 1999; 2001). In part this stabilization is accomplished on the basis of reflexive mechanisms, such as the vestibulocollic (VCR) and cervicocollic (CCR) reflexes through vestibular and muscle spindle stimulation, respectively (Peterson et al., 1985). During locomotion, we do not see complete stabilization of the head in space, but instead an intermittent position around discrete angular positions, accomplished by large head relative to trunk motion (Hirasaki et al., 1999; Imai et al., 2001; Moore et al., 1999, 2001; Pozzo et al., 1990, 1995). In addition, vestibulo-ocular reflex (VOR) adjustments allow for compensatory eye movements in response to head movement to align gaze with desired visual information (Hirasaki et al., 1999; Imai et al., 2001; Moore et al., 1999, 2001; Pozzo et al., 1990, 1995). Visual perception during locomotor tasks often involves head orientation towards environmental features of interest to facilitate gaze alignment, highlighting the visual system’s requirements for a consistent head position in space (Moore et al., 2001).
Vestibulo-ocular reflex characteristics during unidirectional translational whole-body vibration without head restriction
Published in Ergonomics, 2020
Tomoko Sugawara, Hiroyuki Sakai, Yutaka Hirata
The vestibulo-ocular reflex (VOR) is a reflex in which the eyes move in response to head movements, thus playing a crucial role in clarity of vision. Ocular stability, the ability to keep visual targets at the same spot on the retina, is severely compromised by head movements without VOR because visual targets seem to move in the opposite direction, which results in motion blur. Indeed, an early case study reported impaired reading ability in a patient who lost bilateral vestibular sensitivity (Crawford 1964), suggesting the importance of compensatory VOR for maintaining stability in response to tiny head movements during silent reading. Even if the head remains completely still, the VOR is essential for ocular stability in people exposed to whole-body vibration, such as occurs in moving vehicles.
Optical and gravito-inertial contributions to the perception and control of height in a simulated Low-Altitude Flight context
Published in Ergonomics, 2021
Francois Denquin, Jamilah Foucher, Simon Pla, Jean-Christophe Sarrazin, Benoit G. Bardy
Non-flight visuo-vestibular self-motion has been widely investigated regarding perception-action (Fetsch, DeAngelis, and Angelaki 2010; Cullen 2019) and studies have shown the importance of spatiotemporally coherent visuo-vestibular cues for successful control of self-motion (De Winkel et al. 2013; Wright DiZio, and Lackner 2005). Flight-related visuo-vestibular interactions during self-motion have also been studied from a functional point of view. Visuo-vestibular signals are physiologically connected via the vestibulo–ocular Reflex (VOR), where eye movements compensate head motion to maintain stable images. Investigations of the impact of visuo-vestibular cues on VOR showed the necessity of concordant visuo-vestibular stimuli to have efficient visual suppression movements and visual performance (Guedry, Lentz, and Jell 1979; Guedry et al. 1981; Young and Merfeld 1993). Studies on non-flight visuo-vestibular interaction without self-motion were shown to influence orientation and distance judgement. Visual distance judgments were exaggerated when vestibular galvanic stimulation was presented with head-tilt, forward and backward tilts resulting in under- and over-estimated distances. Objects presented above and below the horizon when tilted backward resulted respectively in over- and under-estimates of distance (Török et al. 2017). Extrapolating these findings to visuo-vestibular interaction with self-motion in flight could explain commonly occurring pitch-related SD illusions (Previc and Ercoline 2004; Gillingham and Wolfe 1986). Lastly, it is known that discrepancies (non-coherence, noise) in the flight environment can lead to misinterpretations of self-motion leading to loss-of-control (Pennings et al. 2020; Lewkowicz and Biernacki 2020). Vibrational noise flight-simulation investigations have reported that the presence of vibration can both improve and degrade performance, where differences were attributed to fatigue (Stave 1979).