Impact of low visual contrast on posture, motion sickness, and performance in VR

2021 ◽  
Author(s):  
Jordan J. Garner ◽  
Michael D'Zmura
Keyword(s):  
Motion Sickness ◽  
Visual Contrast ◽  
And Performance

Repeated Assessment of Stress, Mood and Performance Changes Resulting from Exposure to Vessel Motions at Sea

1979 ◽  
Vol 23 (1) ◽  
pp. 549-553 ◽  
Author(s):  
Ross L. Pepper ◽  
Steven F. Wiker
Keyword(s):  
Visual Search ◽  
Motion Sickness ◽  
Affective State ◽  
Coast Guard ◽  
Potential Contribution ◽  
Physiological Measures ◽  
Repeated Testing ◽  
Performance Tasks ◽  
And Performance ◽  
Auditory Monitoring

A preliminary study was conducted with six experienced male Coast Guardsmen and a small monohull vessel (95' Coast Guard Patrol Boat) to evaluate the feasibility of a proposed experimental paradigm as well as the sensitivity of an array of performance, physiological and affective state measures to vessel motions and motion sickness. Performance measures (e.g. Navigation Plotting, Critical Tracking, Visual Search, Complex Auditory Monitoring, Grammatical Reasoning, etc.), physiological measures (e.g., motion sickness severity, stress hormone excretion, urine output and specific gravity), and affective state measures (e.g., mood dimensions) were sampled continuously for eight hours each day for three consecutive days. All variables were compared between control (dockside, engines running) and steaming conditions (four-hour octagonal steaming patterns were repeated twice each eight hour day). Results show all physiological measures examined to be sensitive to the Influence of vessel motions or motion sickness. Motion sickness severity was found to rise and fall depending upon the encounter direction of the vessel to the movement of the primary swell; steaming courses with head or bow seas produced significantly greater degrees of illness than did courses possessing stern or quartering seas. Vessel motions led to significant increases in crew fatigue and changes in concentration. Some performance tasks (e.g. Navigation Plotting and Visual Search) were degraded at sea despite the potential contribution of practice effects, habituation to stress and motivation to perform. The Implications of such factors are discussed In terms of past, current and future performance assessment paradigms utilizing repeated testing.

The role of vection, eye movements and postural instability in the etiology of motion sickness

2004 ◽  
Vol 14 (4) ◽  
pp. 335-346 ◽  
Author(s):  
Moira B. Flanagan ◽  
James G. May ◽  
Thomas G. Dobie
Keyword(s):  
Eye Movements ◽  
Motion Sickness ◽  
Well Being ◽  
Postural Instability ◽  
Theoretical Approaches ◽  
Precise Understanding ◽  
Point Analysis ◽  
And Performance ◽  
Self Motion

Motion sickness is a term that is commonly used to describe the ill effects of many provocative motion (e.g. seagoing or air travel) and apparent motion (e.g. IMAX movies and virtual reality) environments on human well-being and performance. It can be extremely debilitating and yet we do not have a precise understanding of its cause. This study evaluates the importance of three factors that are purported to be involved in the etiology of motion sickness (MS). Most provocative motion environments cause three distinct, but possibly related, responses: reflexive eye movements (EM), sensory conflict (SC), and postural instability (PS). Three current theories, concerning the etiology of motion sickness, emphasize one of these responses, but deny the importance of the others. Such theoretical approaches preclude the possibility of a synergistic interaction of these factors. This experiment employed a three-factor experimental design wherein each factor was manipulated alone or in combination with the others. The independent variables involved two levels of: PS (induced by having the subject stand on a stationary platform or on a posturally challenging platform mounted atop a partially inflated rubber inner tube); SC (with or without illusory self movement elicited visually by whole field stimulation); and EM (unrestricted or controlled by a stable fixation point). Analysis of measures of PS, SC and EM confirmed the effectiveness of these manipulations. Analysis of MS measures (questionnaires, magnitude ratings, tolerance times) revealed a main effect of SC (p < 0.01), increased MS found with illusory self motion conditions. In addition, measures of MS symptomatology revealed a significant three-way interaction between SC, PS and EM (p < 0.05), greater amounts of MS found with conditions of illusory self motion, postural challenge, and unrestricted EM. This suggests support for a multi-factorial approach to the study of MS etiology. These findings suggest a major role of SC in the elicitation of MS, but also suggest important contributions from the EM and PS mechanisms.

Chlorpheniramine and ephedrine in combination for motion sickness

2008 ◽  
Vol 17 (5-6) ◽  
pp. 301-311
Author(s):  
Jay C. Buckey ◽  
Donna L. Alvarenga ◽  
Todd A. MacKenzie
Keyword(s):  
Motion Sickness ◽  
Vertical Axis ◽  
Normal Subjects ◽  
Cognitive Testing ◽  
Double Blind ◽  
Performance Effects ◽  
Objective Tests ◽  
Axis Rotation ◽  
And Performance ◽  
C 50

Background: Chlorpheniramine is effective against motion sickness, but produces sedation. To reduce chlorpheniramine's sedating effect and increase its effectiveness, ephedrine was combined with chlorpheniramine to prevent motion sickness. Methods: Chlorpheniramine (C) and chlorpheniramine plus ephedrine (Chlorphedra) were studied in a randomized, double blind, crossover trial. Eighteen normal subjects were randomized to six different orderings of placebo, C (12 mg) or Chlorphedra (12 mg C + 50 mg ephedrine). They ingested the medication 3.25 hours before off vertical axis rotation in a rotating chair. Cognitive testing with both objective and subjective tests was performed before drug ingestion, at peak drug effect and following rotation. Results: Both C and Chlorphedra significantly increased chair time compared to placebo [6.6 to 10.3 minutes (C), 10.2 minutes (Chlorphedra), p < 0.01]. Subjects reported significantly more sleepiness on the Karolinska sleepiness scale after taking C (3.3 placebo, 4.9 C (p < 0.005)) but not with Chlorphedra (3.3 placebo, 3.1 Chlorphedra). Chlorphedra resulted in significantly higher reported alertness, clearheadedness and attentiveness compared to C. Deficits seen on objective tests with C were corrected with Chlorphedra. Subjects noted more side effects with Chlorphedra. Conclusion: Ephedrine does not increase the effectiveness of chlorpheniramine against motion sickness, but counteracts sedative and performance effects successfully.

DETRIMENTAL EFFECTS OF WIND-INDUCED BUILDING MOTION ON OCCUPANT WORK AND TASK PERFORMANCE

2015 ◽  
Vol 2 (1) ◽  
Author(s):  
K. C. S. Kwok ◽  
S. Lamb ◽  
K. S. Wong
Keyword(s):  
Task Performance ◽  
Motion Sickness ◽  
Work Performance ◽  
Biomechanical Properties ◽  
Body Sway ◽  
Physiological Factors ◽  
Manual Task ◽  
Building Motion ◽  
And Performance ◽  
New Generation

We present recent multidisciplinary research conducted by psychologists, engineers and physiologists investigating the effects of wind-induced building motion on wellbeing, manual task performance and cognitive performance. In a sample of actual office workers, we show that sopite syndrome is the main consequence of exposure to wind-induced building motion. Sopite syndrome, a form of mild motion sickness characterized by drowsiness and low motivation, is the main cause of reductions in work performance. Experimental research shows that biomechanical properties of the human body are influenced by the frequency of motion, which amplifies body sway and interferes with task performance at 0.5 Hz, and to a greater extent with increases in acceleration. Exposure to motion induced sopite syndrome in some participants, who performed significantly worse than unaffected individuals. A new generation of serviceability criteria should aim to minimize sopite syndrome, motion sickness, motion induced body sway, and other psychological and physiological factors, rather than only address perception thresholds, which will likely allow engineers and designers to create a new generation of buildings that will ensure an improved level of comfort and performance for building occupants.

Artificial Horizon Effects on Motion Sickness and Performance

2012 ◽  
Vol 33 (5) ◽  
pp. 878-885 ◽  
Author(s):  
Dror Tal ◽  
Adi Gonen ◽  
Guy Wiener ◽  
Ronen Bar ◽  
Amnon Gil ◽  
...  
Keyword(s):  
Motion Sickness ◽  
And Performance

Comparative Motion Sickness Symptomatology and Performance Decrements Occassioned by Hurricane Penetrations in C-121, C-130, and F-3 Navy Aircraft,

1971 ◽  
Author(s):  
Robert S. Kennedy ◽  
William F. Moroney ◽  
Ronald M. Bale ◽  
Harvey G. Gregoire ◽  
David G. Smith
Keyword(s):  
Motion Sickness ◽  
And Performance

Transmission Scanning Electron Microscopy and Energy Analysis with the Siemens ELMISKOP 101

1972 ◽  
Vol 30 ◽  
pp. 450-451
Author(s):  
H. M. Thieringer
Keyword(s):  
Objective Lens ◽  
Transmission Microscopy ◽  
Image Recording ◽  
Mode Of Operation ◽  
Scanning Transmission ◽  
Electron Microscopes ◽  
And Performance ◽  
Convergent Beam ◽  
Ray Path ◽  
Beam Diffraction

It has repeatedly been show that with conventional electron microscopes very fine electron probes can be produced, therefore allowing various micro-techniques such as micro recording, X-ray microanalysis and convergent beam diffraction. In this paper the function and performance of an SIEMENS ELMISKOP 101 used as a scanning transmission microscope (STEM) is described. This mode of operation has some advantages over the conventional transmission microscopy (CTEM) especially for the observation of thick specimen, in spite of somewhat longer image recording times.Fig.1 shows schematically the ray path and the additional electronics of an ELMISKOP 101 working as a STEM. With a point-cathode, and using condensor I and the objective lens as a demagnifying system, an electron probe with a half-width ob about 25 Å and a typical current of 5.10-11 amp at 100 kV can be obtained in the back focal plane of the objective lens.

Angular Resolved Electron Spectroscopy with Parallel Recording

1990 ◽  
Vol 48 (2) ◽  
pp. 370-371
Author(s):  
Huang Min ◽  
P.S. Flora ◽  
C.J. Harland ◽  
J.A. Venables
Keyword(s):  
Electron Spectroscopy ◽  
Low Voltage ◽  
Solid Angle ◽  
Detection System ◽  
Voltage Electron ◽  
Cylindrical Mirror ◽  
Inner Radius ◽  
Channel Plate ◽  
And Performance ◽  
Type Detector

A cylindrical mirror analyser (CMA) has been built with a parallel recording detection system. It is being used for angular resolved electron spectroscopy (ARES) within a SEM. The CMA has been optimised for imaging applications; the inner cylinder contains a magnetically focused and scanned, 30kV, SEM electron-optical column. The CMA has a large inner radius (50.8mm) and a large collection solid angle (Ω > 1sterad). An energy resolution (ΔE/E) of 1-2% has been achieved. The design and performance of the combination SEM/CMA instrument has been described previously and the CMA and detector system has been used for low voltage electron spectroscopy. Here we discuss the use of the CMA for ARES and present some preliminary results.The CMA has been designed for an axis-to-ring focus and uses an annular type detector. This detector consists of a channel-plate/YAG/mirror assembly which is optically coupled to either a photomultiplier for spectroscopy or a TV camera for parallel detection.

Novel epoxy/anhydride alternatives for biological electron microscopy: Physical and performance characteristis of embed 812 and LX 112 in combination with NSA/NMA/DMAE

1989 ◽  
Vol 47 ◽  
pp. 1000-1001
Author(s):  
Joe A. Mascorro ◽  
Gerald S. Kirby
Keyword(s):  
Electron Microscopy ◽  
Flow Rate ◽  
Succinic Anhydride ◽  
Volume Flow Rate ◽  
Mass Density ◽  
Uranyl Acetate ◽  
Volume Flow ◽  
Base Resin ◽  
And Performance ◽  
Acid Anhydrides

Embedding media based upon an epoxy resin of choice and the acid anhydrides dodecenyl succinic anhydride (DDSA), nadic methyl anhydride (NMA), and catalyzed by the tertiary amine 2,4,6-Tri(dimethylaminomethyl) phenol (DMP-30) are widely used in biological electron microscopy. These media possess a viscosity character that can impair tissue infiltration, particularly if original Epon 812 is utilized as the base resin. Other resins that are considerably less viscous than Epon 812 now are available as replacements. Likewise, nonenyl succinic anhydride (NSA) and dimethylaminoethanol (DMAE) are more fluid than their counterparts DDSA and DMP- 30 commonly used in earlier formulations. This work utilizes novel epoxy and anhydride combinations in order to produce embedding media with desirable flow rate and viscosity parameters that, in turn, would allow the medium to optimally infiltrate tissues. Specifically, embeding media based on EmBed 812 or LX 112 with NSA (in place of DDSA) and DMAE (replacing DMP-30), with NMA remaining constant, are formulated and offered as alternatives for routine biological work.Individual epoxy resins (Table I) or complete embedding media (Tables II-III) were tested for flow rate and viscosity. The novel media were further examined for their ability to infilftrate tissues, polymerize, sectioning and staining character, as well as strength and stability to the electron beam and column vacuum. For physical comparisons, a volume (9 ml) of either resin or media was aspirated into a capillary viscocimeter oriented vertically. The material was then allowed to flow out freely under the influence of gravity and the flow time necessary for the volume to exit was recored (Col B,C; Tables). In addition, the volume flow rate (ml flowing/second; Col D, Tables) was measured. Viscosity (n) could then be determined by using the Hagen-Poiseville relation for laminar flow, n = c.p/Q, where c = a geometric constant from an instrument calibration with water, p = mass density, and Q = volume flow rate. Mass weight and density of the materials were determined as well (Col F,G; Tables). Infiltration schedules utilized were short (1/2 hr 1:1, 3 hrs full resin), intermediate (1/2 hr 1:1, 6 hrs full resin) , or long (1/2 hr 1:1, 6 hrs full resin) in total time. Polymerization schedules ranging from 15 hrs (overnight) through 24, 36, or 48 hrs were tested. Sections demonstrating gold interference colors were collected on unsupported 200- 300 mesh grids and stained sequentially with uranyl acetate and lead citrate.

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