title: Performance of a simple aiming task in hypergravity: II. detailed response characteristics.
abstract: BACKGROUND
  Literature proposes three hypotheses for impaired movement execution in hyper-G. The present study attempted to discriminate between these hypotheses by comparing kinematic characteristics and final accuracy of pointing movements in different gravity levels.
  
  
  METHODS
  Subjects pointed without seeing their hand at targets presented before, during and after exposure to hyper-G.
  
  
  RESULTS
  After factoring out movement amplitude, peak vertical velocity and the skewness of velocity profiles tended to increase, while movement duration tended to decrease with increasing G-level. Further, final response position was slightly less modulated by target position in hyper-G than in normal-G.
  
  
  CONCLUSIONS
  Although not all findings reached statistical significance, the observed pattern of results corroborates the hypothesis (2) that the motor system re-interprets hyper-G as increased arm weight.
authors.affiliation: Institute for Space and Terrestrial Science, North York, Canada.
authors.forename: O
authors.initials: O
authors.lastname: Bock
authors.forename: K E
authors.initials: KE
authors.lastname: Arnold
authors.forename: B S
authors.initials: BS
authors.lastname: Cheung
mesh_terms: D000328:Adult; D000704:Analysis of Variance; D005260:Female; D006801:Humans; D018471:Hypergravity / Q000009:adverse effects*; D008297:Male; D008875:Middle Aged; D011597:Psychomotor Performance; D012044:Regression Analysis