Straight Ahead in Microgravity (Straight Ahead in Microgravity) - 12.28.17

Overview | Description | Applications | Operations | Results | Publications | Imagery

ISS Science for Everyone

Science Objectives for Everyone
Straight-ahead direction is a very basic perceptual reference for spatial orientation, movement, and locomotion. The perceived straight-ahead along the horizontal and vertical meridian is largely determined by both otolith and somatosensory inputs, which are altered in microgravity. During spaceflight, adaptive processes are take place within the central nervous system to take into account the new environment, and compute new spatial egocentric and world-centered representations or frames of reference. The Straight Ahead in Microgravity investigation measures and monitors how these frames change over time by investigating eye movements and perceptual reports.
Science Results for Everyone
Information Pending

The following content was provided by Gilles Clement, Ph.D., Scott J. Wood, Ph.D., and is maintained in a database by the ISS Program Science Office.
Information provided courtesy of the Erasmus Experiment Archive.
Experiment Details

OpNom: Straight Ahead

Principal Investigator(s)
Gilles Clement, Ph.D., International Space University (ISU), Strasbourg, France
Scott J. Wood, Ph.D., Azusa Pacific University, Azusa, CA, United States

Information Pending

European Space Agency (ESA), Noordwijk, Netherlands

Sponsoring Space Agency
European Space Agency (ESA)

Sponsoring Organization
Information Pending

Research Benefits
Earth Benefits, Scientific Discovery, Space Exploration

ISS Expedition Duration
March 2015 - March 2016; March 2016 - February 2018; -

Expeditions Assigned

Previous Missions
Information Pending

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Experiment Description

Research Overview
• The subjective straight-ahead direction is a very basic frame of reference for spatial orientation, movement, and locomotion. The perceived straight-ahead in the horizontal and vertical directions is largely determined by inputs from sensory organs both in the inner ear and around the body which are altered in weightlessness and will hence change this point of reference. A change in an individual's frames of reference might have negative consequences on evaluating the direction of an approaching object, or on the accuracy of reaching movements, or locomotion, or manual control.
• This project will measure and monitor how this frame of reference changes over time by investigating eye movements and perceptual reports. The experiment will test subject’s perception of the straight-ahead direction after exposure to weightlessness through various experimental conditions using a recording system to monitor left and right eye movements and linear accelerometers and angular velocity sensors placed around the body to monitor head, arm, and trunk movements. The experiment will also test the use of a vibrotactile belt that stimulates the torso when the body is titled relative to the gravitational vertical to provide an orientation cue that will improve subject’s performance after landing.
• Investigating how weightlessness affects perception is important for understanding the problems associated with long-term effects of weightlessness on astronauts and how they re-adapt to the return of gravitational forces, on Earth, the Moon and on Mars. This project has therefore theoretical, practical and even clinical implications.

Information Pending

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Space Applications
The mechanisms of perception and orientation undergo adaptation under the influence of weightlessness and readaptation when returning to gravity. Without gravity to act as a stimulus, astronauts rely more heavily on visual perception for orientation and this study investigates the change in straight-ahead perception after long-duration space flight. Understanding what altered visual perception occurs (during and) after long-term exposure to weightlessness, and what areas of the brain are responsible, is an important element in making sure that this does not present any issues for undertaking mission activities. Results generated could form a key part of mission planning and therefore optimise the chances of achieving all mission goals and secure optimal mission success.

Earth Applications
Understanding how the neural processes of perception readapt to gravity after exposure to long-duration weightlessness has an obvious immediate impact in assisting with an astronaut’s readaptation after a long-duration mission. From a broader perspective this research could improve our fundamental knowledge of how the human central nervous system functions on earth. Furthermore drawing similarities between the disorientation experienced by astronauts when first adapting to weightlessness and certain medical conditions on earth where disorientation can be an important symptom, can provide important information of the areas of the brain responsible which could help with the treatment of such conditions. The development of these research protocols promises to provide a new tool for clinical testing of spatial cognition, altered in pathological conditions and in normal aging.

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Operational Requirements and Protocols
• Pre-flight
o 3 sessions (minimum 2):
• L-120 days +/-30 days
• L-90 days +/-30 days
• L-60 days +/-30 days
o Minimum 3 days between 2 sessions. 1 session consists of:
• Eye and arm movement calibrations;
• Searching with eyes for non-existent target;
• Fixating a visual target at straight ahead direction at near and far distance;
• Self-paced saccadic eye and arm movements using tilt chair and vibrotactile belt;
• Fixating visual targets at near or far distance using occlusion option, sled, and vibrotactile belt.
• In-flight: no sessions.
• Post-flight
o 3 sessions (minimum 2):
• R+0 day or R+1 day
• R+4 days +/-1 day
• R+8 days +/- 2 days
o The first session is mandatory to study re-adaptive effects.
o Refer to Pre-flight for session information.

Baseline Data Collection (BDC) should not be scheduled:
• Within 4 hours after another perceptual or vestibular experiment;
• At the end of the working day (fatigue and loss of vigilance);
• On the day following time-shifting of more than 6 hours.

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Decadal Survey Recommendations

Information Pending

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Results/More Information

Information Pending

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Related Websites

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