1,516 research outputs found

    Aerospace medicine and biology: A continuing bibliography with indexes (supplement 355)

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    This bibliography lists 147 reports, articles and other documents introduced into the NASA Scientific and Technical Information System during October, 1991. Subject coverage includes: aerospace medicine and psychology, life support systems and controlled environments, safety equipment, exobiology and extraterrestrial life, and flight crew behavior and performance

    Neuroscience discipline science plan

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    Over the past two decades, NASA's efforts in the neurosciences have developed into a program of research directed at understanding the acute changes that occur in the neurovestibular and sensorimotor systems during short-duration space missions. However, the proposed extended-duration flights of up to 28 days on the Shuttle orbiter and 6 months on Space Station Freedom, a lunar outpost, and Mars missions of perhaps 1-3 years in space, make it imperative that NASA's Life Sciences Division begin to concentrate research in the neurosciences on the chronic effects of exposure to microgravity on the nervous system. Major areas of research will be directed at understanding (1) central processing, (2) motor systems, (3) cognitive/spatial orientation, and (4) sensory receptors. The purpose of the Discipline Science Plan is to provide a conceptual strategy for NASA's Life Sciences Division research and development activities in the comprehensive area of neurosciences. It covers the significant research areas critical to NASA's programmatic requirements for the Extended-Duration Orbiter, Space Station Freedom, and exploration mission science activities. These science activities include ground-based and flight; basic, applied, and operational; and animal and human research and development. This document summarizes the current status of the program, outlines available knowledge, establishes goals and objectives, identifies science priorities, and defines critical questions in the subdiscipline areas of nervous system function. It contains a general plan that will be used by NASA Headquarters Program Offices and the field centers to review and plan basic, applied, and operational intramural and extramural research and development activities in this area

    USSR Space Life Sciences Digest, Issue 18

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    This is the 18th issue of NASA's USSR Life Sciences Digest. It contains abstracts of 50 papers published in Russian language periodicals or presented at conferences and of 8 new Soviet monographs. Selected abstracts are illustrated with figures and tables from the original. A review of a recent Aviation Medicine Handbook is also included. The abstracts in this issue have been identified as relevant to 37 areas of space biology and medicine. These areas are: adaptation, aviation medicine, biological rhythms, biospherics, body fluids, cardiovascular and respiratory systems, cytology, developmental biology, endocrinology, enzymology, equipment and instrumentation, exobiology, gastrointestinal system, genetics, gravitational biology, group dynamics, habitability and environmental effects, hematology, human performance, immunology, life support systems, man-machine systems, mathematical modeling, metabolism, microbiology, musculoskeletal system, neurophysiology, nutrition, operational medicine, perception, personnel selection, psychology, radiobiology, reproductive biology, space biology and medicine, and space industrialization

    Integrated Research Plan to Assess the Combined Effects of Space Radiation, Altered Gravity, and Isolation and Confinement on Crew Health and Performance: Problem Statement

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    Future crewed exploration missions to Mars could last up to three years and will expose astronauts to unprecedented environmental challenges. Challenges to the nervous system during these missions will include factors of: space radiation that can damage sensitive neurons in the central nervous system (CNS); isolation and confinement can affect cognition and behavior; and altered gravity that will change the astronauts perception of their environment and their spatial orientation, and will affect their coordination, balance, and locomotion. In the past, effects of spaceflight stressors have been characterized individually. However, long-term, simultaneous exposure to multiple stressors will produce a range of interrelated behavioral and biological effects that have the potential to adversely affect operationally relevant crew performance. These complex environmental challenges might interact synergistically and increase the overall risk to the health and performance of the astronaut. Therefore, NASAs Human Research Program (HRP) has directed an integrated approach to characterize and mitigate the risk to the CNS from simultaneous exposure to these multiple spaceflight factors. The proposed research strategy focuses on systematically evaluating the relationships among three existing research risks associated with spaceflight: Risk of Acute (In-flight) and Late Central Nervous System Effects from Radiation (CNS), Risk of Adverse Cognitive or Behavioral Conditions and Psychiatric Disorders (BMed), and Risk of Impaired Control of Spacecraft/Associated Systems and Decreased Mobility Due to Vestibular/Sensorimotor Alterations Associated with Spaceflight (SM). NASAs HRP approach is intended to identify the magnitude and types of interactions as they affect behavior, especially as it relates to operationally relevant performance (e.g., performance that depends on reaction time, procedural memory, etc.). In order to appropriately characterize this risk of multiple spaceflight environmental stressors, there is a recognition of the need to leverage research approaches using appropriate animal models and behavioral constructs. Very little has been documented on the combined effects of altered gravity, space radiation, and other psychological and cognitive stressors on the CNS. Preliminary evidence from rodents suggest that a combination of a minimum of exposures to even two of three stressors of: simulated space radiation, simulated microgravity, and simulated isolation and confinement, have produced different and more pronounced biological and performance effects than exposure to these same stressors individually. Structural and functional changes to the CNS of rodents exposed to transdisciplinary combined stressors indicate that important processes related to information processing are likely altered including impairment of exploratory and risk taking behaviors, as well as executive function including learning, memory, and cognitive flexibility all of which may be linked to changes in related operational relevant performance. The fully integrated research plan outlines approaches to evaluate how combined, potentially synergistic, impacts of simultaneous exposures to spaceflight hazards will affect an astronauts CNS and their operationally relevant performance during future exploration missions, including missions to the Moon and Mars. The ultimate goals are to derive risk estimates for the combined, potentially synergistic, effects of the three major spaceflight hazards that will establish acceptable maximum decrement or change in a physiological or behavioral parameters during or after spaceflight, the acceptable limit of exposure to a spaceflight factor, and to evaluate strategies to mitigate any associated decrements in operationally relevant performance

    A Low-Dimensional Model of Coordinated Eye and Head Movements

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    Eye and head movement data, were recorded under head fixed and head-free conditions, and compared with theoretical results obtained using a nonlinear model of eye-head coordination. The model explains slow, or pursuit movement correlated closely to target movement, and saccades, or quick phases of eye movement. Eye movement under head-fixed conditions was modeled by an externally forced Duffing equation, whilst properties of head movement are described by a second externally forced Duffing equation with lower eigen frequency. In the more natural, head-free conditions where both eye and head movements are used synergetically to pursue a visual target, the vestibulocular reflex (VOR) is represented by coefficients defining the mutual coupling between these two oscillatory systems. In the present model, the oscillator that models eye movement has an inhibitory influence on head movement; head to eye coupling coefficients are included to model the influence of the VOR mechanism. Individual eye and head movement patterns in different subjects can be adequately modeled by altering the coupling coefficients. In order to adequatcly simulate those changes introduced by microgravity conditions, the coefficients defining eye-head coordination (mutual coupling) must be changed. It may be hypothesized tlmt such changes in the neurovestibular system could introduce the instability in eye-head coordination, which is known to lead to space sickness.Whitehall Foundation (S93-24

    Aerospace medicine and biology: A continuing bibliography with indexes (supplement 327)

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    This bibliography lists 127 reports, articles and other documents introduced into the NASA Scientific and Technical Information System during August, 1989. Subject coverage includes: aerospace medicine and psychology, life support systems and controlled environments, safety equipment, exobiology and extraterrestrial life, and flight crew behavior and performance

    Postural instability in an immersive Virtual Reality adapts with repetition and includes directional and gender specific effects

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    The ability to handle sensory conflicts and use the most appropriate sensory information is vital for successful recovery of human postural control after injury. The objective was to determine if virtual reality (VR) could provide a vehicle for sensory training, and determine the temporal and spatial nature of such adaptive changes. Twenty healthy subjects participated in the study (10 females). The subjects watched a 90-second VR simulation of railroad (rollercoaster) motion in mountainous terrain during five repeated simulations, while standing on a force platform that recorded their stability. The immediate response to watching the VR movie was an increased level of postural instability. Repeatedly watching the same VR movie significantly reduced both the anteroposterior (62%, p < 0.001) and lateral (47%, p = 0.001) energy used. However, females adapted more slowly to the VR stimuli as reflected by higher use of total (p = 0.007), low frequency (p = 0.027) and high frequency (p = 0.026) energy. Healthy subjects can significantly adapt to a multidirectional, provocative, visual environment after 4–5 repeated sessions of VR. Consequently, VR technology might be an effective tool for rehabilitation involving visual desensitisation. However, some females may require more training sessions to achieve effects with VR

    Aerospace medicine and biology: A continuing bibliography with indexes, supplement 129, June 1974

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    This special bibliography lists 280 reports, articles, and other documents introduced into the NASA scientific and technical information system in May 1974

    Stroboscopic Augmented Reality as an Approach to Mitigate Gravitational Transition Effects During Interplanetary Spaceflight

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    During interplanetary spaceflight, periods of extreme gravitational transitions will occur such as transitions between hypergravity, hypogravity, and microgravity. Following gravitational transitions, rapid sensorimotor adaptation or maladaptation may occur which can affect gaze control and weaken dynamic visual acuity in astronauts. A reduction in dynamic visual acuity during spaceflight could possibly impact or impair mission critical activities (e.g., control of extraterrestrial machinery/vehicles and other important tasks). Stroboscopic visual training is an emerging visual tool that has been terrestrially observed to enhance visual performance and perception by performing tasks under conditions of intermittent vision. This technique has also been seen to increase the dynamic visual acuity for individuals terrestrially. To mitigate the decreased dynamic visual acuity that is observed in astronauts following gravitational transitions, stroboscopic vision training may serve as a potential countermeasure. We describe the effects of gravitational transitions on the vestibulo-ocular system and dynamic visual acuity, review terrestrial stroboscopic visual training, and report the novel development of stroboscopic augmented reality as a possible countermeasure for G-transitions in future spaceflight
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