Mental Representation of Spatial Cues During Spaceflight (3D-Space) Nervous and Vestibular Systems
Research Area: Nervous and Vestibular Systems
Expedition(s): 17- 28
Principal Investigator(s): ● Gilles Clement, International Space University,
Strasbourg, France
RESEARCH OBJECTIVES
The Mental Representation of Spatial Cues During Spaceflight (3D-Space) experiment investigates
the effects of exposure to microgravity on the mental representation of spatial cues by astronauts
during and after spaceflight. The absence of the gravitational frame of reference during
spaceflight could be responsible for disturbances in the mental representation of spatial cues,
such as the perception of horizontal and vertical lines, the perception of an object’s depth, and
the perception of a target’s distance. The results of this study could have important
consequences for human performance during spaceflight.
RESULTS
Visual illusions based on perspective are less
intense in microgravity. This suggests that the
perspective cue is less crucial for depth
perception. When a subject in space adjusted
the dimensions of a 3-D cube so that it looked
normal, its height was shorter and its depth
was greater than when performing this test in
normal gravity; when a subject in space drew
a Necker cube with the eyes closed, its height
was shorter and its depth was greater. This
indicated that the cognitive and the sensory-
motor representations of 3-D objects both
adapt to space.
It is well known that perception of size and
distance are usually related. When
underestimating the distance of an object,
people tend to attribute a small size to this
object. In agreement with this, it was observed
that space subjects indeed underestimated (by
up to 20%) distance more than on Earth. These
results indicated that the visual space of the
astronauts (ie, the visual component of the perceptual representation of the world around
them) was distorted in space. Interestingly, similar effects have been recently reported in
spatial neglect and vestibular-defective patients. The speed of drawing and writing was less in
microgravity compared to ground. The asymmetry between up and down vertical motion also
tended to disappear in microgravity. These results confirmed those obtained previously in
pointing experiments.
European Space Agency astronaut Paolo Nespoli,
conducts the Mental Representation of Spatial Cues
During Spaceflight (3D-Space) experiment in the
Columbus laboratory of the International Space
Station. 3D-Space involves distance, written and
illusion exercises, and is testing the hypothesis that
altered visual perception affects motor control. NASA
image.