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Perspective Reversible Figures in Microgravity (Reversible_Figures)
Principal Investigator
Research Area:
Behavior and performance
Species Studied
Scientific Name: Homo sapiens Species: Human

Previous research suggests that the reliance on linear perspective cues for three-dimensional (3D) visual perception decreases when subjects are tilted relative to gravity and in microgravity during parabolic and orbital flight. Based on this observation, it is likely that the adaptive changes in the processing of gravitational information by the neurovestibular system during space flight may alter 3D visual perception.

The objective of the Reversible Figures experiment was to investigate whether the perception of ambiguous figures is affected by microgravity. The hypothesis is that the number of perceived reversals of perspective-based reversible figures is altered in microgravity when compared to normal gravity, but that the perceived reversal of 2D figures is not affected. Ambiguous reversible figures are seen with a statistically known preference in 1g. This hypothesis is to be verified by determining for all phases of the space flight: (1) the time for first reversal and the number of perceived reversals of 3D and 2D reversible figures in a given time frame; and (2) the probability for seeing each view/reversal within a figure.

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Clément G and Ngo-Anh J. Adaptation of the central nervous system to space flight: Past, current and future studies. European Journal of Applied Physiology 2013. July; 113(7):1655-72. []

Clément G, and Demel M. Perceptual reversal of bi-stable figures in microgravity and hypergravity during parabolic flight. Neuroscience Letters 2012. January 24; 507(2):143-6. []

Lim D, Demel M, Kohli S, and Clément G. Effects of gravity direction on the percept reversal of ambiguous figures. Aviation, Space and Environmental Medicine. 2009. 80: 278-279.

Visual perception

Photo Gallery
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Data Information
Data Availability
Archive is complete. No data sets are available for this experiment. Please Contact LSDA if you know of available data for this investigation.

Depth perception
Number of reversals
Percentage of time
Reaction time
Time to first reversal
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Mission/Study Information
Mission Launch/Start Date Landing/End Date Duration
Expedition 32 07/01/2012 09/16/2012 78 days
Expedition 33 09/16/2012 11/18/2012 63 days
Expedition 34 11/18/2012 03/15/2013 117 days
Expedition 35 03/15/2013 05/13/2013 58 days
Expedition 36 05/13/2013 09/10/2013 166 days
Expedition 37 09/10/2013 11/10/2013 61 days
Expedition 38 11/10/2013 03/10/2014 120 days
Expedition 39 03/10/2014 05/13/2014 64 days
Expedition 40 05/13/2014 09/10/2014 133 days

Additional Information
Managing NASA Center
Johnson Space Center (JSC)
Responsible NASA Representative
Johnson Space Center LSDA Office
Project Manager: Jessica Keune
Institutional Support
European Space Agency (ESA)
Proposal Date