WorldCat Identities

U.S. Army Aeromedical Research Laboratory

Overview
Works: 287 works in 345 publications in 1 language and 841 library holdings
Roles: Originator
Classifications: TL589.35.H44, 629.1
Publication Timeline
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Most widely held works about U.S. Army Aeromedical Research Laboratory
 
Most widely held works by U.S. Army Aeromedical Research Laboratory
Helmet-mounted displays : sensation, perception, and cognition issues( Book )

1 edition published in 2009 in English and held by 83 WorldCat member libraries worldwide

Addresses the field of human factors engineering, military night flight operations, and the visual and auditory science behind the improvements in advanced aviation and other Warfighter sensor systems
Evaluation of the gust-alleviation characteristics and handling qualities of a free-wing aircraft by Richard F Porter( Book )

1 edition published in 1970 in English and held by 20 WorldCat member libraries worldwide

Directional differences in visual acuity during vertical nystagmus by W. Carroll Hixson( )

2 editions published in 1969 in English and held by 18 WorldCat member libraries worldwide

Twenty naval aviator candidates were exposed to four ramp velocity test profiles generated by the Human Disorientation Device. The head orientation was such that the y (left-right) axis was on the Earth-vertical rotational center of the device, with the resulting alpha y pitch stimulation eliciting vertical nystagmus which was recorded on all four profiles. During two of the profiles, the subjects were required to observe a visual target consisting of a vertically aligned series of dots and to report the duration of the period where dot fusion or target blur occurred as a result of the vertical nystagmus. It was found that during pitch forward angular acceleration resulting in nystagmus with a slow component upward, the loss of visual acuity was of a significantly longer duration than that present during stimulation in the opposite direction. Directional differences in the vertical nystagmus response were also observed. (Author)
Ganglion cell response characteristics from the area centralis in the intact eye of the cat by Roy H Steinberg( )

2 editions published in 1968 in English and held by 18 WorldCat member libraries worldwide

Ganglion cell responses were recorded with microelectrodes from the intact eye to focused spots and annuli of light delivered by a dual-beam ophthalmoscope. Only concentrically organized circular receptive fields were analysed. Thresholds for optimal center and surround stimuli were approximately equal, as were the latencies of on-responses from the center and surround. With whole-field stimulation center-dominance was a function of light intensity. Off-responses and center-surround interaction were observed with brief flashes (5 msec, 10 msec). With increases of flash duration the duration of the on-response did not increase by the full increment of the flash until the flashes were 50 to 80 msec. At high-flash intensities the on-response extended into the off-period and the off-response weakened and disappeared; it occurred with both on-excitation and on-inhibition and for the responses of both center and surround. These intensity effects were also studied in an intracellular recording; at high intensities, the rate of repolarization of the postsynaptic potential decreased, and the latency of repolarization was delayed. (Author)
An analysis of the d.c. component of the local electroretinogram in the intact eye of the cat by Roy H Steinberg( )

2 editions published in 1967 in English and held by 18 WorldCat member libraries worldwide

The local electroretinogram (LERG) was recorded with microelectrodes from the intact eye in response to focused spots and annuli delivered by a dual-beam ophthalmoscope. The d.c. component was readily isolated from the b-wave on the basis of a lower threshold, smaller summation area, and greater resistance to light adaptation, thereby supporting a hypothesis that separates these components. At high flash intensities the d.c. component increased in duration as its decay was delayed; a slowing in decay rate also occurred and an earlier off-response was revealed. These effects were influenced by flash duration and the level of light adaptation. The late receptor potential was also recorded from the area centralis after clamping the retinal circulation at the optic disk. At moderate levels of light adaptation it was isolated from the c-wave and exhibited a rapid decay-phase. The behavior of the late RP in response to increases in flash intensity and duration paralled the behavior of the d.c. component. (Author)
The effect of prior exposure to a harmful event upon subsequent performance under threat by Xenia Coulter( )

2 editions published in 1969 in English and held by 18 WorldCat member libraries worldwide

The present study investigated effects of (1) the stated probability at .25 versus .85 with no pretest shock demonstration and (2) pretest shock demonstration versus no demonstration with the stated probability held constant at .65. Subjects were 70 entering aviation trainees. The task was a subject-paced, four-choice discrimination task. Ten subjects were used as controls, with the remainder divided among the experimental conditions. A 5-minute practice period without threat preceded a 5-minute experimental period for all conditions. It was concluded that (1) shock demonstration is not necessary, and its elimination would provide a more useful range for individual difference measurement; (2) .65 probability is better for producing measurable performance decrement than either the lower or higher extremes of .25 and .85; (3) threat perception as measured by mean performance level across time may be as useful a parameter as performance decrement immediately preceding the anticipated harmful stimulus. (Author)
Environmental factors affecting the performance of infrared CO₂ analyzer and the estimation of alveolar CO₂ tension by Pei Chin Tang( )

2 editions published in 1968 in English and held by 18 WorldCat member libraries worldwide

Theoretical equations were derived from known physico-chemical laws to determine the effects of room temperature and barometric pressure on the performance of the infrared type of CO2 analyzer. They were first tested experimentally and then against empirical equations derived from the Godart nomogram. These equations were found to be valid and useful in the estimation of the fractional concentration of CO2 of gas mixtures under various environmental conditions. Minimal gas temperature recorded with a thermistor probe at the inlet of the analyzer was used to estimate the water vapor pressure of gas samples in the analyzer chamber. This method was experimentally tested to be valid in estimating CO2 fractional concentrations of heated wet gas mixtures. It was used to estimate the alveolar CO2 tension of human subjects with various end-tidal sampling methods. Methods used by others with this type of analyzer were discussed. (Author)
Influence of vestibular stimulation and display luminance on the performance of a compensatory tracking task by Richard D Gilson( )

2 editions published in 1970 in English and held by 18 WorldCat member libraries worldwide

Loss of acuity for visual details in aircraft during unusual maneuvers has been documented. Recent investigations of this problem have served to define the magnitude of semicircular canal stimulation necessary to produce nystagmus of sufficient strength to degrade visual acuity. Present work extends former observations by investigating the effects of levels of illumination during semicircular canal stimulation on the performance of a task requiring vision. The illumination levels were selected to encompass the range used in aircraft cockpits. A compensatory tracking task with an aircraft instrument as the display provided an indirect measure of this loss of visual acuity and a direct practical measure of performance. (Author)
Rod-cone interaction in s-potentials from cat retina by Roy H Steinberg( )

2 editions published in 1969 in English and held by 16 WorldCat member libraries worldwide

Rod-cone interaction in cat S-potentials was studied by analyzing the effect of wavelength and intensity upon the form of dark-adapted responses. Flashes of white light and relatively monochromatic flashes produced responses that seemed to originate from the excitation of both receptor types. The rod response changed as a function of intensity, peaking at approx. 2.5 log above threshold and increasing in duration at approx. 3.0 log above threshold. The cone response seemed in some way to add to the changing rod response. V-Log I curves showed that the rod responses reached a ceiling (initial peak voltage) at approx. 3.5 log above threshold while the maintained voltage leveled off at a lower intensity. Both ceilings were obscured by the apparent addition of the cone contribution. Cone and rod responses to brief orange and blue lights of moderate intensity, separated in time, added together across a complete range of intervals. (Author)
The rod after-effect in s-potentials from cat retina by Roy H Steinberg( )

2 editions published in 1969 in English and held by 16 WorldCat member libraries worldwide

The relation of the rod after-effect to percentage rhodopsin bleached was studied in S-potentials from cat retina. At threshold, flashes which produced the rod after-effect bleached only very small quantities of rhodopsin; and at a fixed flash duration, the duration of the after-effect increased as a function of log intensity. The after-effect's threshold occurred at about the intensity which saturated the maintained voltage. With flash intensity fixed (6.5 log td. scotopic) and flash duration increased (0.5 to 64.0 sec) the duration of the after-effect was a linear function of exposure time. The duration continued to increase after an exposure of 16 sec, even though at least 99 per cent of the rhodopsin had been bleached. It is concluded that the after-effect originates from something which accumulates after the maintained voltage in rod pathways reaches a ceiling. The accumulation can continue at a fixed rate irrespective of the bleaching rate. (Author)
A triaxial accelerometer module for vestibular application by W. Carroll Hixson( )

2 editions published in 1968 in English and held by 16 WorldCat member libraries worldwide

A brief description is given of a 6-channel instrumentation module developed for collection of preliminary acceleration data for the a priori determination of optimal characteristics for transducers to be installed permanently on various aircraft and man-rated research devices for the measurement of vestibular-significant acceleration stimuli. The module utilizes three linear and three angular accelerometers, all of the standard, commercially available, servo type, to measure the triaxial linear and triaxial angular accelerations, along and about, respectively, the roll, pitch, and yaw axes of the test device or vehicle. Signal-conditioning amplifiers equipped with feedback circuitry to facilitate in-flight adjustment of gain and high-frequency rolloff characteristics are provided for optimal utilization of the dynamic range capabilities of magnetic tape data storage recorders. Though the instrument is used primarily to collect acceleration data in the 0-5 cps spectrum, the linear channels can also be used in determining vibration levels in the 0-100 cps range. (Author)
Two procedures for applied and experimental studies of stress by Robert S Kennedy( )

3 editions published in 1970 in English and held by 16 WorldCat member libraries worldwide

To compensate for the low reliability of physiological manifestations of sympathetic nervous system activity two methods are offered. The first method requires a major research program by which a valid criterion of stress would be determined by experimentation, and then predictors of this criterion would be obtained empirically by correlational techniques. These predictors could then be crossvalidated. By using the predictors, the influences of psychological stress and physiological stress could be separated. Whether a functional relationship exists between the magnitude of the response to stress and the probability of its occurrence could then be determined. The second method is similar but less exact. It has been used successfully in motion sickness studies and avoids the necessity of a long exploratory program with numerous pilot studies. A procedure for the control and the regulation of the perception of the magnitude of the stress to the organism (human and infrahuman) is offered for use with the two methods. The lack of suitable control of this factor is discussed in connection with previous research. (Author)
Assessment of semicircular canal function by Gale G Owens( )

2 editions published in 1969 in English and held by 16 WorldCat member libraries worldwide

Two methods were compared for measuring subjective angular displacement produced by triangular waveforms of angular velocity while subjects (N = 11) were enclosed in a vertical-axis rotation device that excluded visual and auditory cues of angular motion. Accuracy of subjective estimates was influenced by the methods and by the magnitudes of the acceleration comprising the stimulus waveforms. Results suggest that one of the methods, with slight modification, will provide reliable indication of the subjective effects of controlled semicircular canal stimulation. (Author)
The semiautomated test system : a tool for standardized performance testing by H. Rudy Ramsey( )

2 editions published in 1969 in English and held by 16 WorldCat member libraries worldwide

Performance tests which are truly standardized must be administered in a way that will minimize variation due to operator intervention and errors. Through such technological developments as low-cost digital computers and digital logic modules, automatic test administration without restriction of test content has become possible. A semiautomated test system (SATS) which incorporates programmable digital logic modules for control has been developed to allow an experimental psychologist, unassisted and with a minimum of special training, to set up and modify tests or experiments; thus, it is especially useful for exploratory studies. The structure of the SATS is described and an example is presented to clarify the operations involved in its use. (Author)
Assessment of semicircular canal function by Fred E Guedry( )

2 editions published in 1969 in English and held by 16 WorldCat member libraries worldwide

Two methods were compared for measuring subjective angular displacement produced by triangular waveforms of angular velocity while subjects (N = 11) were enclosed in a vertical-axis rotation device that excluded visual and auditory cues of angular motion. Accuracy of subjective estimates was influenced by the methods and by the magnitudes of the acceleration comprising the stimulus waveforms. Results suggest that one of the methods, with slight modification, will provide reliable indication of the subjective effects of controlled semicircular canal stimulation. (Author)
Orientation-error accidents in regular army uh-1 aircraft during fiscal year 1967 : relative incidence and cost by W. Carroll Hixson( )

2 editions published in 1970 in English and held by 16 WorldCat member libraries worldwide

The report dealing with the magnitude of the pilot disorientation/ vertigo accident problem in Regular Army UH-1 helicopter operations. Incidence and cost data presented for fiscal year 1967 include a total of 50 major and minor orientation-error accidents (15 of which were fatal), resulting in 38 fatalities, 88 nonfatal injuries, and a total UH-1 aircraft damage cost of $7, 542,177. (Author)
Cross-validation of a brief vestibular disorientation test administered by a variety of personnel by Rosalie K Ambler( )

2 editions published in 1967 in English and held by 16 WorldCat member libraries worldwide

A Brief Vestibular Disorientation Test (BVDT) was developed that involves observer assessment of subjects' reactions produced by head movements in a rotating chair. Promising validity coefficients have been reported for a criterion of pass versus separation from pilot training. This study cross-validated the BVDT under observer conditions approximating field use. The test was administered to 239 aviation trainees during pre-flight training. The number of observers per subject varied from two to four. Thirteen observers with a variety of backgrounds participated. BVDT scores were correlated with four criteria: (1) students separated from training for all causes versus completions, (2) tension separations versus all others, (3) airsick separations versus all others, (4) tension and/or airsick separations versus all others. Significant relationships existed between high sensitivity scores on the BVDT and membership in all four separation groups. The addition of the BVDT significantly augmented the magnitude of the multiple correlations of the existing aviation selection variables with the criteria. (Author)
The effect of semicircular canal stimulation during tilting on the subsequent perception of the visual vertical by Charles W Stockwell( )

2 editions published in 1969 in English and held by 16 WorldCat member libraries worldwide

When a man is accelerated on a centrifuge, the direction of gravitoinertial vertical changes relative to his body. However, a lag occurs in his perception of this change. The hypothesis has been advanced that the perceptual lag in this situation is partly the result of a conflict between signals arising from the semicircular canals and from the otolith organs. To test this hypothesis, subjects were tilted in such a way that they received consistent semicircular canal and otolith signals. This was accomplished simply by tilting them 30 deg from upright in their frontal plane. Immediately after being tilted, these subjects made estimates of the vertical which were approximately accurate, and they continued to make accurate estimates throughout a 140-sec judgment period. The absence of a perceptual lag under these circumstances supports the hypothesis. (Author)
Orientation-error accidents in regular army aircraft during fiscal year 1967 : relative incidence and cost by W. Carroll Hixson( )

2 editions published in 1970 in English and held by 16 WorldCat member libraries worldwide

Instrumentation for measurement of vestibular-significant forces in helicopters by W. Carroll Hixson( )

2 editions published in 1968 in English and held by 16 WorldCat member libraries worldwide

The report describes an airborne instrumentation system developed at minimal cost from standard, commercially available components for the in-flight acquisition and storage of helicopter low-frequency motion data pertinent to the investigation of vestibular-related pilot disorientation. System components provided to measure and record the instantaneous triaxial linear acceleration and instantaneous triaxial angular velocity of the aircraft at a given crew station include three potentiometer readout linear accelerometers, three similar gimballess rate gyros, six signal-conditioning amplifiers, and a 7-channel, battery-powered, IRIG-compatible, magnetic tape recorder. (Author)
 
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Alternative Names
Aeromedical Research Laboratory

Aeromedical Research Laboratory (U.S.)

Army Aeromedical Research Laboratory

U.S.A.A.R.L.

U.S.Army Aeromedical Research Laboratory

United States Aeromedical Research Laboratory

United States Army Aeromedical Research Laboratory

United States Army Army Aeromedical Research Laboratory

United States Army U.S.Army Aeromedical Research Laboratory

United States Army US Army Aeromedical Research Laboratory

United States U.S. Army Aeromedical Research Laboratory

US Army Aeromedical Research Laboratory

USA Army Aeromedical Research Laboratory

USAARL

Languages
English (40)