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Cohen, M. M.

Publications and source records attributed to Cohen, M. M..

At least 19 records
All sourcesNASA NTRSDOE OSTI
NASA NTRS2001

Thresholds for Shifting Visually Perceived Eye Level Due to Incremental Pitches

Visually perceived eye level (VPEL) was judged by subjects as they viewed a luminous grid pattern that was pitched by 2 or 5 deg increments between -20 deg and +20 deg. Subjects were dark adapted for 20 min and indicated--VPEL by directing the beam of a laser pointer to the rear wall of a 1.25 m cubic pitch box that rotated about a horizontal axis midpoint on the rear wall. Data were analyzed by ANOVA and the Tukey HSD procedure. Results showed a 10.0 deg threshold for pitches P(sub i) above the reference pitch P(sub 0), and a -10.3 deg threshold for pitches P(sub i) below-the reference-pitch P(sub 0). Threshold data for pitches P(sub i) < P(sub 0) suggest an asymmetric threshold for VPEL below and above physical eye level.

Scott, Donald M.↗
NASA NTRS2001

Effects of gravitational and optical stimulation on the perception of target elevation

To examine the combined effects of gravitational and optical stimulation on perceived target elevation, we independently altered gravitational-inertial force and both the orientation and the structure of a background visual array. While being exposed to 1.0, 1.5, or 2.0 Gz in the human centrifuge at NASA Ames Research Center, observers attempted to set a target to the apparent horizon. The target was viewed against the far wall of a box that was pitched at various angles. The box was brightly illuminated, had only its interior edges dimly illuminated, or was kept dark. Observers lowered their target settings as Gz was increased; this effect was weakened when the box was illuminated. Also, when the box was visible, settings were displaced in the same direction as that in which the box was pitched. We attribute our results to the combined influence of otolith-oculomotor mechanisms that underlie the elevator illusion and visual-oculomotor mechanisms (optostatic responses) that underlie the perceptual effects of viewing pitched visual arrays.

NASA Discipline Neuroscience↗
NASA NTRS1997

Effects of Orientation on Recognition of Facial Affect

The ability to discriminate facial features is often degraded when the orientation of the face and/or the observer is altered. Previous studies have shown that gross distortions of facial features can go unrecognized when the image of the face is inverted, as exemplified by the 'Margaret Thatcher' effect. This study examines how quickly erect and supine observers can distinguish between smiling and frowning faces that are presented at various orientations. The effects of orientation are of particular interest in space, where astronauts frequently view one another in orientations other than the upright. Sixteen observers viewed individual facial images of six people on a computer screen; on a given trial, the image was either smiling or frowning. Each image was viewed when it was erect and when it was rotated (rolled) by 45 degrees, 90 degrees, 135 degrees, 180 degrees, 225 degrees and 270 degrees about the line of sight. The observers were required to respond as rapidly and accurately as possible to identify if the face presented was smiling or frowning. Measures of reaction time were obtained when the observers were both upright and supine. Analyses of variance revealed that mean reaction time, which increased with stimulus rotation (F=18.54, df 7/15, p (is less than) 0.001), was 22% longer when the faces were inverted than when they were erect, but that the orientation of the observer had no significant effect on reaction time (F=1.07, df 1/15, p (is greater than) .30). These data strongly suggest that the orientation of the image of a face on the observer's retina, but not its orientation with respect to gravity, is important in identifying the expression on the face.

Cohen, M. M.↗
NASA NTRS1996

Reduction of the elevator illusion from continued hypergravity exposure and visual error-corrective feedback

Ten subjects served as their own controls in two conditions of continuous, centrifugally produced hypergravity (+2 Gz) and a 1-G control condition. Before and after exposure, open-loop measures were obtained of (1) motor control, (2) visual localization, and (3) hand-eye coordination. During exposure in the visual feedback/hypergravity condition, subjects received terminal visual error-corrective feedback from their target pointing, and in the no-visual feedback/hypergravity condition they pointed open loop. As expected, the motor control measures for both experimental conditions revealed very short lived underreaching (the muscle-loading effect) at the outset of hypergravity and an equally transient negative aftereffect on returning to 1 G. The substantial (approximately 17 degrees) initial elevator illusion experienced in both hypergravity conditions declined over the course of the exposure period, whether or not visual feedback was provided. This effect was tentatively attributed to habituation of the otoliths. Visual feedback produced a smaller additional decrement and a postexposure negative after-effect, possible evidence for visual recalibration. Surprisingly, the target-pointing error made during hypergravity in the no-visual-feedback condition was substantially less than that predicted by subjects' elevator illusion. This finding calls into question the neural outflow model as a complete explanation of this illusion.

NASA Program Space Physiology and Countermeasures↗
NASA NTRS1993

Visual and somesthetic influences on postural orientation in the median plane

We investigated optic and somesthetic contributions to perceived body orientation in the pitch dimension. In a within-subject factorial design, each of 12 subjects attempted to set his/her body erect or 45 degrees back from erect while restrained in a movable bed surrounded by an adjustable box. The box provided a visual environment consisting of either a grid pattern, two luminous lines, or complete darkness. Both the grid pattern and the luminous lines were effective at biasing settings of body position when the box was pitched; the pitched grid was more effective than the pitched lines. Although the pitch of the box influenced orientation to both goals, the effect was greater for the diagonal goal than for the erect goal. We present a model of postural orientation in the median plane that involves vestibular, somatosensory, and visual inputs.

Nemire, K.↗
NASA NTRS1992

Human performance in the modern cockpit

This panel was organized by the Aerospace Human Factors Committee to illustrate behavioral research on the perceptual, cognitive, and group processes that determine crew effectiveness in modern cockpits. Crew reactions to the introduction of highly automated systems in the cockpit will be reported on. Automation can improve operational capabilities and efficiency and can reduce some types of human error, but may also introduce entirely new opportunities for error. The problem solving and decision making strategies used by crews led by captains with various personality profiles will be discussed. Also presented will be computational approaches to modeling the cognitive demands of cockpit operations and the cognitive capabilities and limitations of crew members. Factors contributing to aircrew deviations from standard operating procedures and misuse of checklist, often leading to violations, incidents, or accidents will be examined. The mechanisms of visual perception pilots use in aircraft control and the implications of these mechanisms for effective design of visual displays will be discussed.

Dismukes, R. K.↗
NASA NTRS1989

Effect of structured visual environments on apparent eye level

Each of 12 subjects set a binocularly viewed target to apparent eye level; the target was projected on the rear wall of an open box, the floor of which was horizontal or pitched up and down at angles of 7.5 degrees and 15 degrees. Settings of the target were systematically biased by 60% of the pitch angle when the interior of the box was illuminated, but by only 5% when the interior of the box was darkened. Within-subjects variability of the settings was less under illuminated viewing conditions than in the dark, but was independent of box pitch angle. In a second experiment, 11 subjects were tested with an illuminated pitched box, yielding biases of 53% and 49% for binocular and monocular viewing conditions, respectively. The results are discussed in terms of individual and interactive effects of optical, gravitational, and extraretinal eye-position information in determining judgements of eye level.

NASA Center ARC↗
NASA NTRS1985

Human factors in space station architecture 1: Space station program implications for human factors research

The space station program is based on a set of premises on mission requirements and the operational capabilities of the space shuttle. These premises will influence the human behavioral factors and conditions on board the space station. These include: launch in the STS Orbiter payload bay, orbital characteristics, power supply, microgravity environment, autonomy from the ground, crew make-up and organization, distributed command control, safety, and logistics resupply. The most immediate design impacts of these premises will be upon the architectural organization and internal environment of the space station.

Cohen, M. M.↗
NASA NTRS1985

Laboratory glassware rack for seismic safety

A rack for laboratory bottles and jars for chemicals and medicines has been designed to provide the maximum strength and security to the glassware in the event of a significant earthquake. The rack preferably is rectangular and may be made of a variety of chemically resistant materials including polypropylene, polycarbonate, and stainless steel. It comprises a first plurality of parallel vertical walls, and a second plurality of parallel vertical walls, perpendicular to the first. These intersecting vertical walls comprise a self-supporting structure without a bottom which sits on four legs. The top surface of the rack is formed by the top edges of all the vertical walls, which are not parallel but are skewed in three dimensions. These top edges form a grid matrix having a number of intersections of the vertical walls which define a number of rectangular compartments having varying widths and lengths and varying heights.

Cohen, M. M.↗
NASA NTRS1985

Proceedings of the Seminar on Space Station Human Productivity

An exploration of the issues which surround some of the elements of the Human Productivity Program is given. Five general topics were discussed: (1) crew safety, (2) internal contamination, (3) the definition of the Human Productivity Program, (4) aspects of architecture that affect productivity, and (5) the role of mock-ups in the Human Productivity Program.

Cohen, M. M.↗
NASA NTRS1985

Space station crew safety: Human factors interaction model

A model of the various human factors issues and interactions that might affect crew safety is developed. The first step addressed systematically the central question: How is this space station different from all other spacecraft? A wide range of possible issue was identified and researched. Five major topics of human factors issues that interacted with crew safety resulted: Protocols, Critical Habitability, Work Related Issues, Crew Incapacitation and Personal Choice. Second, an interaction model was developed that would show some degree of cause and effect between objective environmental or operational conditions and the creation of potential safety hazards. The intermediary steps between these two extremes of causality were the effects on human performance and the results of degraded performance. The model contains three milestones: stressor, human performance (degraded) and safety hazard threshold. Between these milestones are two countermeasure intervention points. The first opportunity for intervention is the countermeasure against stress. If this countermeasure fails, performance degrades. The second opportunity for intervention is the countermeasure against error. If this second countermeasure fails, the threshold of a potential safety hazard may be crossed.

Cohen, M. M.↗
NASA NTRS1985

Overview: Human Factors Issues in Space Station Architecture

An overview is presented of human factors issues in space station architecture. The status of the space station program is given. Habitability concerns such as vibroacoustics, lighting systems, privacy and work stations are discussed in detail.

Cohen, M. M.↗
NASA NTRS1984

Waterproof Raised Floor Makes Utility Lines Accessible

Floor for laboratories, hospitals and factories waterproof yet allows access to subfloor utilities. Elevated access floor system designed for installations with multitude of diverse utility systems routed under and up through floor and requirement of separation of potentially conflicting utility services. Floor covered by continuous sheet of heat resealable vinyl. Floor system cut open when changes are made in utility lines and ducts. After modifications, floor covering resealed to protect subfloor utilities from spills and leaks.

Cohen, M. M.↗
NASA NTRS1984

Space station architecture, module, berthing hub, shell assembly, berthing mechanism and utility connection channel

The geometric form of a space station is presented that includes a description of a plurality of modules and berthing hubs, joined by interconnections which are sideways connectable. The modules and hubs are fastened together in a triangular configuration in three dimensions. The interconnections include a pair of opposed, axially aligned, flanged ports and a clamp latch formed from a plurality of sections hinged along their length and extending circumferentially around the flanged ports. A hermetic seal is formed between the ports. A utilities connection channel extends between the ports. The channel has a shell with utilities connectors movable between an extended position to mating connectors in the modules and a withdrawn position. Assembly sequence and common module shell structure is detailed.

Cohen, M. M.↗
NASA NTRS1984

Space Station crew safety - Human factors model

A model of the various human factors issues and interactions that might affect crew safety is developed. The first step addressed systematically the central question: How is this Space Station different from all other spacecraft? A wide range of possible issue was identified and researched. Five major topics of human factors issues that interacted with crew safety resulted: Protocols, Critical Habitability, Work Related Issues, Crew Incapacitation and Personal Choice. Second, an interaction model was developed that would show some degree of cause and effect between objective environmental or operational conditions and the creation of potential safety hazards. The intermediary steps between these two extremes of causality were the effects on human performance and the results of degraded performance. The model contains three milestones: stressor, human performance (degraded) and safety hazard threshold. Between these milestones are two countermeasure intervention points. The first opportunity for intervention is the countermeasure against stress. If this countermeasure fails, performance degrades. The second opportunity for intervention is the countermeasure against error. If this second countermeasure fails, the threshold of a potential safety hazard may be crossed.

Cohen, M. M.↗