RESUMO
Objective To explore the effect of weightlessness simulation on processing speed of mental rotation of males in 72 h head-down tilt,in order to further reveal human performance changes caused by weightlessness.Methods During 72 h weightlessness simulation (9 am day 1 to 9 pm day 4,head-down tilt started from 9 pm day 1),16 male subjects were processed speed of rotation data byhand picture mental rotation (test 8 times),using self cross-references design,and the variation of processing speed of mental rotation by duration was analyzed.Results The linear regression analysis showed,the reaction time of each time point for each subject as the independent variable,the angle of rotation as the dependent variable,with the extension of simulated weightlessness time.The intercept(constant term of the regression equation),indicating the processing speed of non-rotation,were gradually increased with HDT time,but didn(t) reached significantly difference (F(3,14) =0.551,P =0.650) ;the slope(Regression coefficient of the regression equation),indicating the processing speed of rotation.were gradually increased with HDT time,and reached the significantly difference (F(3,14) =4.338,P =0.009).The value of intercept and slope was like upside-down U in three days,and reached the highest value at day 2.Conclusion Weightlessness simulation have affection on the speed of mental rotation,especially on the rotation speed.