The hypothesis that exposure to prolonged free fall is a form of sensorymotor rearrangement rather than a direct change in otolith sensitivity or sensory compensation for a reduced otolith input is discussed. Data from Spacelab-1 experiment 1NS-104 are presented to support an otolith reinterpretation hypothesis. This experiment measured vestibulo-spinal reflex changes as a function of sustained free fall. Findings indicate that when a monosynaptic reflex (H-reflex), measured from the major postural muscles (soleus) is used, adaptation to space flight includes a change in how the central nervous system interprets a fall. In a normal gravity environment a sudden unexpected fall produces a potentiated H-reflex. After 7 days inflight, an equivalent fall does not potentiate the reflex. Postflight a greatly increased reflex is observed in those crewmen most susceptible to space motion sickness.
The adaptation of vestibulo-spinal reflexes as a function of spaceflight and their relationship to space motion sickness
1984-08-01
Aufsatz (Konferenz)
Keine Angabe
Englisch
Spatial Transformation of the Vestibulo-Ocular during Spaceflight
British Library Online Contents | 1996
|Vestibulo-spinal reflex mechanisms
NTRS | 1981
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