A study of attention and psychological time Final report
Psychophysics of human attention, and sensory and time discrimination
Kristofferson, A. B.↗
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Impaired motion detection preceding smooth eye movements.
Experiments have been carried out that suggest that the observed psychophysical impairment of motion detection in man may not occur equally over the entire visual field. Instead, if impaired motion detection is a consequence of redirection of 'attention' to another portion of the visual field, then movement detection may be impaired the most in the fovea and the least in the region of the subsequent target.
Richards, W.↗
Ride quality - An exploratory study and criteria development
The Langley six degree of freedom visual motion simulator has been used to measure subjective response ratings of the ride quality of eight segments of flight, representative of a wide variation in comfort estimates. The results indicate that the use of simulators for this purpose appears promising. A preliminary approach for the development of criteria for ride quality ratings based on psychophysical precepts is included.
Stone, R. W., Jr.↗
Vertex evoked potentials in a rating-scale detection task: Relation to signal probability
Vertex evoked potentials were recorded from human subjects performing in an auditory detection task with rating scale responses. Three values of a priori probability of signal presentation were tested. The amplitudes of the N1 and P3 components of the vertex potential associated with correct detections of the signal were found to be systematically related to the strictness of the response criterion and independent of variations in a priori signal probability. No similar evoked potential components were found associated with signal absent judgements (misses and correct rejections) regardless of the confidence level of the judgement or signal probability. These results strongly support the contention that the form of the vertex evoked response is closely correlated with the subject's psychophysical decision regarding the presence or absence of a threshold level signal.
Squires, K. C.↗
Investigation of pilot's role and display requirements in automatic landings
Two experimental capabilities were developed on the PDP-12 computers. The first of these was an experimental monitor to perform experiments in the psychophysics of visual target motion prediction, discrimination, etc., and exercises the (limited) graphical capabilities of the PDP-12. The original monitor was modified to include the capability of handling more than 64 stimuli without reinitializing the program. The second experimental monitor was programmed and was used to investigate pilot decisions in low visibility approaches. The details of this experimental capability, which has great potential for exploring decisions and behavior, are described in detail.
Curry, R. E.↗
Human comfort response to random motions with a dominant transverse motion
Subjective ride comfort response ratings were measured on the Langley Visual Motion Simulator with transverse acceleration inputs with various power spectra shapes and magnitudes. The results show only little influence of spectra shape on comfort response. The effects of magnitude on comfort response indicate the applicability of psychophysical precepts for comfort modeling.
Stone, R. W., Jr.↗
The Mark 3 Haploscope
A computer-operated binocular vision testing device was developed as one part of a system designed for NASA to evaluate the visual function of astronauts during spaceflight. This particular device, called the Mark 3 Haploscope, employs semi-automated psychophysical test procedures to measure visual acuity, stereopsis, phoria, fixation disparity, refractive state and accommodation/convergence relationships. Test procedures are self-administered and can be used repeatedly without subject memorization. The Haploscope was designed as one module of the complete NASA Vision Testing System. However, it is capable of stand-alone operation. Moreover, the compactness and portability of the Haploscope make possible its use in a broad variety of testing environments.
Decker, T. A.↗
Noise and Speech Interference: Proceedings of Minisymposium
Several papers are presented which deal with the psychophysical effects of interference with speech and listening activities by different forms of noise masking and filtering. Special attention was given to the annoyance such interruptions cause, particularly that due to aircraft flyover noises. Activities such as telephone listening and television watching were studied. A number of experimental investigations are described and the results are analyzed.
Shepherd, W. T.↗
Human comfort response to random motions with a dominant longitudinal motion
Subjective ride comfort response ratings were measured on the Langley Visual Motion Simulator with longitudinal acceleration inputs with various power spectra shapes and magnitudes. The results show only little influence of spectra shape on comfort response. The effects of magnitude on comfort response indicate the applicability of psychophysical precepts for comfort modeling.
Stone, R. W., Jr.↗
Peripheral visual response time and retinal luminance-area relations
Experiments were undertaken to elucidate the stimulus luminance-retinal area relationship that underlies response time (RT) behavior. Mean RT was significantly faster to stimuli imaged beyond about 70 deg of arc from the fovea when their luminance was increased by an amount equal to the foveal stimulus luminance multiplied by the cosine of the angle between the peripheral stimuli and the line of sight. This and additional data are discussed in relation to previous psychophysical data and to possible response mechanisms.
Haines, R. F.↗
Vertex evoked potentials in a rating-scale detection task - Relation to signal probability
Results of vertex-evoked potential studies conducted to determine how decision confidence level and decision probability interact to determine P3 amplitude for both signal-present and signal-absent decisions. They support the contention that the form of the vertex-evoked response is closely correlated with the subject's psychophysical response regarding the presence or absence of a threshold-level signal.
Squires, K. C.↗
Foundations of space biology and medicine. Volume 2, book 2: Ecological and physiological bases of space biology and medicine
The influence on living organisms of radiant energy, the psychophysical problems of space flight, methods of physiological investigations in flight, and the transmission of information are considered.
Calvin, M.↗
Human confort response to random motions with a dominant rolling motion
Subjective ride comfort response ratings were measured on a visual motion simulator with rolling velocity inputs with various power spectra shapes and magnitudes. The results show only little influence of spectra shape on comfort response. The effects of magnitude on comfort response indicate the applicability of psychophysical precepts for comfort modeling.
Stone, R. W., Jr.↗
Ernst Mach on the vestibular organ 100 years ago
The paper reviews the contributions of Ernst Mach to vestibular research. His experiments, mainly psychophysical in nature, included measurements of threshold and investigation of the vestibular-visual interaction. Among his conclusions are that the adequate stimulus for the semicircular canals must be pressure, and that the sustained endolymph flow theory of Breuer (1874) and Crum Brown (1874) is erroneous. Excerpts are given of Mach's publications on vestibular functions.-
Henn, V.↗
Visual space perception on a computer graphics night visual attachment
A series of experiments was conducted to compare five psychophysical methods of measuring how people perceive visual space in simulators. Psychologists have used such methods traditionally to measure visual space perception in the real world. Of the five tasks - objective-size judgments, angular-size judgments, shape judgments, slant judgments, and distance judgments - only the angular-size judgment task proved to be of potential use as a measure of simulator realism. In this experiment pilots estimated the relative angular size of triangles placed at various distances along a simulated runway. Estimates made when the display was collimated were closer to real-world performance than estimates made with an uncollimated display.
Palmer, E.↗
Difference thresholds for judgments of sink rate during the flare
Past studies have shown that touchdown rates of descent (sink rates) are higher in aircraft simulators than in aircraft under similar conditions. The objective of this paper was to use a psychophysical technique to investigate a pilot's ability to distinguish between two different sink rates close to the ground. The pilots observed a collimated computer graphics display of a typical runway with edge, zone, and centerline lights. The results showed that with a forward velocity of 120 knots, pilots could reliably distinguish between a sink rate of 0.5 m/sec (1.7 ft/sec) and 0.9 m/sec (2.9 ft/sec). The results also showed that the absolute rate of sink did not significantly affect the perception of sink rate. Time of sink and total height drop during the sink did affect the minimum detectable difference between sink rates (the differential threshold). The effects were such that a greater time of sink and greater height drop produced lower thresholds
Palmer, E.↗
A study of moving base simulation motion cues utilizing washout technique
The present study was conducted to derive data on non-visual motion thresholds utilizing washout technique, and to develop specific threshold values for use as washout parameters. It describes the results of acceleration detection studies carried out using the NASA MSFC General Purpose Simulator which provides six degree-of-freedom cab motion. A series of experiments was performed to test the hypothesis that constant velocity visual cues might suppress non-visual deceleration sensitivity. The psychophysical method employed was the forced-choice procedure which theoretically yields a pure sensitivity measure. The MSFC General Purpose Simulator was programmed to provide velocity ramps in three axes - pitch, fore-aft translation, and vertical translation. Data were collected with and without a constant velocity visual input. Comparison of the current results with classical data suggested significantly greater sensitivity of the human observer to fore-aft accelerations than has generally been reported, sensitivity tending to depend on motion direction and sign of velocity change.
Kirkpatrick, M., III↗
Effects of background gravity stimuli on gravity-controlled behavior
Physiological and developmental effects of altered gravity were researched. The stimulus properties of gravity have been found to possess reinforcing and aversive properties. Experimental approaches taken, used animals placed into fields of artificial gravity, in the form of parabolic or spiral centrifuges. Gravity preferences were noted and it was concluded that the psychophysics of gravity and background factors which support these behaviors should be further explored.
Mccoy, D. F.↗