Tactile influences on astronaut visual spatial orientation: human
neurovestibular experiments on sls-2.
Young, Laurence R., Juan C. Mendoza, Nicolas Groleau, Paul W. Wojcik.
Man-Vehicle Lab, Massachusetts Institute of Technology, MIT,
Currently at School of Medicine, University of Pittsburgh, Recom
Technologies, Inc.
APStracts 2:0365A, 1995.
Human spatial orientation in space flight is initially disturbed by
the absence of usable graviceptor information from the otolith
organs. Experiments measuring astronaut visually induced motion
(vection) strength on various flight days during the first 10 days of
the Spacelab SLS-2 mission demonstrated two new phenomena, in
addition to confirming the initial increased weighting of visual and
localized tactile cues. The reliance upon tactile and visual non
-inertial cues apparently declined after a week in space, as crew
became able to utilize their internal reference frame. Subjects also
showed that even non-directional tactile cues served as a direction
anchor, and inhibited visually induced roll sensation relative to a
new loosely tethered test condition. Individual perceptual styles
were again revealed among the four astronauts tested. The
readaptation to 1-g similarly shows a period of reinterpretation of
inertial and visual cues tospatialorintation. The results are
discussed in terms of an internal model representation of body
orientation, with time varying weights applied to extrinsic and
intrinsic signals.
Received 23 December 1994; accepted in final form 4 August 1995.
APS Manuscript Number A1318-4.
Article publication pending Journal of Applied Physiology.
ISSN 1080-4757 Copyright 1995 The American Physiological Society.
Published in APStracts on 24 August 1995.