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At least 199 records · Page 11
All sourcesNASA NTRSDOE OSTI
NASA NTRS1997

The uncertain response in humans and animals

There has been no comparative psychological study of uncertainty processes. Accordingly, the present experiments asked whether animals, like humans, escape adaptively when they are uncertain. Human and animal observers were given two primary responses in a visual discrimination task, and the opportunity to escape from some trials into easier ones. In one psychophysical task (using a threshold paradigm), humans escaped selectively the difficult trials that left them uncertain of the stimulus. Two rhesus monkeys (Macaca mulatta) also showed this pattern. In a second psychophysical task (using the method of constant stimuli), some humans showed this pattern but one escaped infrequently and nonoptimally. Monkeys showed equivalent individual differences. The data suggest that escapes by humans and monkeys are interesting cognitive analogs and may reflect controlled decisional processes prompted by the perceptual ambiguity at threshold.

Non-NASA Center↗
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 NTRS1996

A test of the deadline model for speed-accuracy tradeoffs

Two experiments were conducted to evaluate the deadline model for speed-accuracy tradeoffs. According to the deadline model, participants in speeded-response tasks terminate stimulus discrimination as soon as it has run to completion or as soon as a predetermined time deadline has arrived, whichever comes first. Speed is traded for accuracy by varying the time deadlines; short deadlines yield fast but sometimes inaccurate responses, whereas long deadlines allow for slow, accurate responses. A new prediction of this model, based on a comparison of reaction time distributions, was derived and tested in experiments involving the joint manipulation of speed stress and stimulus discriminability. Clear violations of this prediction were observed when participants made relative brightness judgments (Experiment 1) and when they made lexical decisions (Experiment 2), rejecting both the deadline model and the fast-guess model. Several alternative models for speed-accuracy tradeoffs, including random-walk and accumulator models, are compatible with the results.

Discrimination (Psychology)↗
NASA NTRS1995

Investigations of the pathogenesis of acquired pendular nystagmus

We investigated the pathogenesis of acquired pendular nystagmus (APN) in six patients, three of whom had multiple sclerosis. First, we tested the hypothesis that the oscillations of APN are due to a delay in visual feedback secondary, for example, to demyelination of the optic nerves. We manipulated the latency to onset of visually guided eye movements using an electronic technique that induces sinusoidal oscillations in normal subjects. This manipulation did not change the characteristics of the APN, but did superimpose lower-frequency oscillations similar to those induced in normal subjects. These results are consistent with current models for smooth (non-saccadic) eye movements, which predict that prolongation of visual feedback could not account for the high-frequency oscillations that often characterize APN. Secondly, we attempted to determine whether an increase in the gain of the visually-enhanced vestibulo-ocular reflex (VOR), produced by viewing a near target, was accompanied by a commensurate increase in the amplitude of APN. Increases in horizontal or vertical VOR gain during near viewing occurred in four patients, but only two of them showed a parallel increase in APN amplitude. On the other hand, APN amplitude decreased during viewing of the near target in the two patients who showed no change in VOR gain. Taken together, these data suggest that neither delayed visual feedback nor a disorder of central vestibular mechanisms is primarily responsible for APN. More likely, these ocular oscillations are produced by abnormalities of internal feedback circuits, such as the reciprocal connections between brainstem nuclei and cerebellum.

NASA Program Space Physiology and Countermeasures↗
NASA NTRS1986

M.I.T./Canadian vestibular experiments on the Spacelab-1 mission: 4. Space motion sickness: symptoms, stimuli, and predictability

Space sickness symptoms were observed by 4 specially trained observers on Spacelab-1. Three reported persistent symptoms, and vomited repeatedly during the first and/or second day of flight. Head movements on all axes were provocative, particularly in pitch and roll. Head acceleration data recorded from 2 symptomatic crewmen showed that after several hours of physical activity in orbit, symptoms appeared, and thereafter both crewmen were compelled to limit head movements. Firm body contact with motionless surfaces helped alleviate symptoms. When crewmembers floated into unfamiliar body orientations in the cabin, inherent ambiguities in static visual orientation cues sometimes produced spatial reorientation episodes which were also provocative. Symptoms largely resembled those of other forms of prolonged motion sickness, superimposed upon other symptoms attributable to fluid shift. All 4 eventually used anti-motion sickness drugs. When they did, vomiting frequency was reduced. By the 4th day, symptoms subsided, and head accelerations again increased in magnitude and variability. Sickness intensity in orbit was not predicted by statistically concordant results of 6 acute preflight susceptibility tests. However, results from a longer duration preflight prism goggles test showed an apparent correlation. All subjects were asymptomatic making head movements in parabolic flight 4 days after the mission, but not 1 year later. Overall, results support the view that space sickness is a motion sickness.

Non-NASA Center↗
NASA NTRS2004

Forty-five years after Broadbent (1958): still no identification without attention

According to D. E. Broadbent's (1958) selective filter theory, people do not process unattended stimuli beyond the analysis of basic physical properties. This theory was later rejected on the basis of numerous findings that people identify irrelevant (and supposedly unattended) stimuli. A careful review of this evidence, however, reveals strong reasons to doubt that these irrelevant stimuli were in fact unattended. This review exposed a clear need for new experiments with tight control over the locus of attention. The authors present 5 such experiments using a priming paradigm. When steps were taken to ensure that irrelevant stimuli were not attended, these stimuli produced no priming effects. Hence, the authors found no evidence that unattended stimuli can be identified. The results support a modern version of Broadbent's selective theory, updated to reflect recent research advances. 2004 APA.

Randomized Controlled Trial↗
NASA NTRS2003

Processing Digital Imagery to Enhance Perceptions of Realism

Multi-scale retinex with color restoration (MSRCR) is a method of processing digital image data based on Edwin Land s retinex (retina + cortex) theory of human color vision. An outgrowth of basic scientific research and its application to NASA s remote-sensing mission, MSRCR is embodied in a general-purpose algorithm that greatly improves the perception of visual realism and the quantity and quality of perceived information in a digitized image. In addition, the MSRCR algorithm includes provisions for automatic corrections to accelerate and facilitate what could otherwise be a tedious image-editing process. The MSRCR algorithm has been, and is expected to continue to be, the basis for development of commercial image-enhancement software designed to extend and refine its capabilities for diverse applications.

Woodell, Glenn A.↗
NASA NTRS2014

Virtual Reality as a Medium for Sensorimotor Adaptation Training and Spaceflight Countermeasures

Astronauts experience a profound sensorimotor adaptation during transition to and from the microgravity environment of space. With the upcoming shift to extra‐long duration missions (upwards of 1 year) aboard the International Space Station, the immediate risks to astronauts during these transitory periods become more important than ever to understand and prepare for. Recent advances in virtual reality technology enable everyday adoption of these tools for entertainment and use in training. Embedding an individual in a virtual environment (VE) allows the ability to change the perception of visual flow, elicit automatic motor behavior and produce sensorimotor adaptation, not unlike those required during long duration microgravity exposure. The overall goal of this study is to determine the feasibility of present head mounted display technology (HMD) to produce reliable visual flow information and the expected adaptation associated with virtual environment manipulation to be used in future sensorimotor adaptability countermeasures. To further understand the influence of visual flow on gait adaptation during treadmill walking, a series of discordant visual flow manipulations in a virtual environment are proposed. Six healthy participants (3 male and 3 female) will observe visual flow information via HMD (Oculus Rift DK2) while walking on an instrumented treadmill at their preferred walking speed. Participants will be immersed in a series of VE's resembling infinite hallways with different visual characteristics: an office hallway, a hallway with pillars and the hallway of a fictional spacecraft. Participants will perform three trials of 10 min. each, which include walking on the treadmill while receiving congruent or incongruent visual information via the HMD. In the first trial, participants will experience congruent visual information (baseline) where the hallway is perceived to move at the same rate as their walking speed. The final two trials will be randomized among participants where the hallway is perceived to move at either half (0.5x) or twice (2.0x) their preferred walking speed. Participants will remain on the treadmill between trials and will not be warned of the upcoming change to visual flow to minimize preparatory adjustments. Stride length, step frequency and dual‐support time will be quantified during each trial. We hypothesize that participants will experience a rapid modification in gait performance during periods of adaptive change, expressed as a decrease in step length, an increase in step frequency and an increase in dual‐support time, followed by a period of adaptation where these movement parameters will return to near‐baseline levels. As stride length, step frequency and dual support times return to baseline values, an adaptation time constant will be derived to establish individual time‐to‐adapt (TTA). HMD technology represents a paradigm shift in sensorimotor adaptation training where gait adaptability can be stressed using off‐the‐shelf consumer products and minimal experimental equipment, allowing for greater training flexibility in astronaut and terrestrial applications alike.

Madansingh, S.↗
NASA NTRS1999

Roll-Tilt Perception Using a Somatosensory Bar Task

Visual estimates of roll-tilt perception during static roll-tilt are confounded by an offset due to the ocular counterroll that simultaneously occurs. An alternative, non-visual ('somatosensory') measure of roll-tilt perception was developed which is not contaminated by this offset. The aims of this study were to determine: 1) inter-subject variability of somatosensory settings across test session in normal subjects and patients with unilateral or bilateral vestibular loss and 2) intra-subject variability of settings across test session in normal subjects.

Black, F. O.↗
DOE OSTI2026

Visualization for Insight and Data Analysis in Energy Research

This talk explores how advanced visualization technologies are transforming analytical reasoning and knowledge discovery in energy research, drawing on recent work at the National Laboratory of the Rockies' Computational Science Center. Through a series of scientific case studies, we demonstrate how immersive and high-resolution visualization environments enable scientists and engineers to identify previously unseen patterns and features - insights that often remain hidden in traditional desktop-based analysis. By embedding richer information into interactive analytics tools, these approaches support the exploration of complex, multivariate parameter spaces, where interaction itself catalyzes understanding. Beyond capability, we emphasize the critical role of visualization design grounded in perception and cognition, showing how visual encodings directly influence analytical outcomes. Spanning applications from materials science to integrated energy systems, these visualization approaches accelerate innovation and improve decision-making by enabling deeper, more reliable insight into increasingly complex energy data.

97 MATHEMATICS AND COMPUTING↗
NASA NTRS1999

Visual-motor recalibration in geographical slant perception

In 4 experiments, it was shown that hills appear steeper to people who are encumbered by wearing a heavy backpack (Experiment 1), are fatigued (Experiment 2), are of low physical fitness (Experiment 3), or are elderly and/or in declining health (Experiment 4). Visually guided actions are unaffected by these manipulations of physiological potential. Although dissociable, the awareness and action systems were also shown to be interconnected. Recalibration of the transformation relating awareness and actions was found to occur over long-term changes in physiological potential (fitness level, age, and health) but not with transitory changes (fatigue and load). Findings are discussed in terms of a time-dependent coordination between the separate systems that control explicit visual awareness and visually guided action.

NASA Center ARC↗
NASA NTRS1981

Influence of combined visual and vestibular cues on human perception and control of horizontal rotation

Measurements are made of manual control performance in the closed-loop task of nulling perceived self-rotation velocity about an earth-vertical axis. Self-velocity estimation is modeled as a function of the simultaneous presentation of vestibular and peripheral visual field motion cues. Based on measured low-frequency operator behavior in three visual field environments, a parallel channel linear model is proposed which has separate visual and vestibular pathways summing in a complementary manner. A dual-input describing function analysis supports the complementary model; vestibular cues dominate sensation at higher frequencies. The describing function model is extended by the proposal of a nonlinear cue conflict model, in which cue weighting depends on the level of agreement between visual and vestibular cues.

Zacharias, G. L.↗
DOE OSTI2023

Visualization Quality Assessment

Understanding how inaccuracies in visualizations affect users’ perception and understanding of scientific data is hard. Inaccuracies in visualizations are quite common and could arise from a range of sources such as errors in the original dataset arising from compression artifacts, errors in the capturing device, noise during transmission of the data, effects due to the algorithm being used to convert data to visualization images, images generated from neural networks, and sources we have yet to discover. Many image quality assessment metrics have been developed to quantify image errors. However, these are usually focused on “natural images” rather than visualizations of scientific data. Common image quality assessment metrics (IQAs) include MSE, PSNR, perceptual metrics such SSIM, FSIM as well as perceptual metrics using deep learning approaches. However, a critical part of understanding how errors are perceived by humans, and subsequently developing more accurate quality assessment metrics, is through user evaluation studies. The goal of this software is to develop a visualization quality assessment (VQA) process that will enable the generation of VQAs that can be used to quantify errors in scientific data visualizations. The VQA development process will include software to support user evaluation experimental design, analysis of visualization differences against standard quality metrics, and the ability to develop additional VQA metrics specific to scientific visualization images.

Grosset, Andre↗
NASA NTRS1975

Perception of linear horizontal self-motion induced by peripheral vision /linearvection/ - Basic characteristics and visual-vestibular interactions

The basic characteristics of the sensation of linear horizontal motion have been studied. Objective linear motion was induced by means of a moving cart. Visually induced linear motion perception (linearvection) was obtained by projection of moving images at the periphery of the visual field. Image velocity and luminance thresholds for the appearance of linearvection have been measured and are in the range of those for image motion detection (without sensation of self motion) by the visual system. Latencies of onset are around 1 sec and short term adaptation has been shown. The dynamic range of the visual analyzer as judged by frequency analysis is lower than the vestibular analyzer. Conflicting situations in which visual cues contradict vestibular and other proprioceptive cues show, in the case of linearvection a dominance of vision which supports the idea of an essential although not independent role of vision in self motion perception.

Berthoz, A.↗
NASA NTRS2002

Heading perception in patients with advanced retinitis pigmentosa

PURPOSE: We investigated whether retinis pigmentosa (RP) patients with residual visual field of < 100 degrees could perceive heading from optic flow. METHODS: Four RP patients and four age-matched normally sighted control subjects viewed displays simulating an observer walking over a ground. In experiment 1, subjects viewed either the entire display with free fixation (full-field condition) or through an aperture with a fixation point at the center (aperture condition). In experiment 2, patients viewed displays of different durations. RESULTS: RP patients' performance was comparable to that of the age-matched control subjects: heading judgment was better in the full-field condition than in the aperture condition. Increasing display duration from 0.5 s to 1 s improved patients' heading performance, but giving them more time (3 s) to gather more visual information did not consistently further improve their performance. CONCLUSIONS: RP patients use active scanning eye movements to compensate for their visual field loss in heading perception; they might be able to gather sufficient optic flow information for heading perception in about 1 s.

Visual Perception↗
NASA NTRS1991

Contextual specificity in perception and action

The visually guided control of helicopter flight is a human achievement, and, thus, understanding this skill is, in part, a psychological problem. The abilities of skilled pilots are impressive, and yet it is of concern that pilots' performance is less than ideal: they suffer from workload constraints, make occasional errors, and are subject to such debilities as simulator sickness. Remedying such deficiencies is both an engineering and a psychological problem. When studying the psychological aspects of this problem, it is desirable to simplify the problem as much as possible, and thereby, sidestep as many intractable psychological issues as possible. Simply stated, we do not want to have to resolve such polemics as the mind-body problem in order to contribute to the design of more effective helicopter systems. On the other hand, the study of human behavior is a psychological endeavor and certain problems cannot be evaded. Four related issues that are of psychological significance in understanding the visually guided control of helicopter flight are discussed. First, a selected discussion of the nature of descriptive levels in analyzing human perception and performance is presented. It is argued that the appropriate level of description for perception is kinematical, and for performance, it is procedural. Second, it is argued that investigations into pilot performance cannot ignore the nature of pilots' phenomenal experience. The conscious control of actions is not based upon environmental states of affairs, nor upon the optical information that specifies them. Actions are coupled to perceptions. Third, the acquisition of skilled actions in the context of inherent misperceptions is discussed. Such skills may be error prone in some situations, but not in others. Finally, I discuss the contextual relativity of human errors. Each of these four issues relates to a common theme: the control of action is mediated by phenomenal experience, the veracity of which is context specific.

Proffitt, Dennis R.↗