45天-6°头低位卧床对视觉注意返回抑制能力的影响

Effects of 45 d-6° Head-down Bed Rest on Inhibition of Return in Visual Attention.

目的观察45天-6°头低位卧床模拟失重条件对个体返回抑制能力产生的影响。方法分别在卧床前第6～4天,卧床第11～13天、第20～22天、第32～34天、第40～42天和卧床后第8～10天采用线索提示范式测试16名男性个体的返回抑制能力。结果刺激始发异步性(SOA)与线索有效性交互作用不显著,说明个体在现有SOA条件下没有出现返回抑制现象。SOA主效应接近边缘显著,个体在SOA为900 ms的反应时显著小于为1200 ms的反应时,且在卧床第11～13天,第20～22天以及卧床后恢复阶段个体在不同SOA条件下的反应时差别消失,说明卧床前期和卧床后恢复阶段个体抑制能力受到了影响,而卧床中期抑制能力逐渐恢复。结论 45天-6°头低位卧床可能延长了个体的认知加工时间,导致产生返回抑制现象需要的SOA延长;卧床条件对个体抑制能力产生了影响,个体在卧床前期以及卧床后恢复阶段的抑制能力受到影响,表现出由受损到适应恢复到受损的变化趋势。

objective To investigate the effects of 45-days of -6° head-down bed rest to simulate weightless- ness on the inhibition of return. Methods 16 male subjects＇ performance on inhibition of return on the 6th 4th days before the rest, on the 11th - 13th, 20th-22th, 32th -34th, 40th -42th days of the rest, and the 8th - 10th days after the rest were tested using spatial cueing paradigm . Results Repeated-measured ANOVA of RTs inhibition of return was not found. However, the main effect of stimulus onset asynchrony （SOA） on the mean RTs was found to be shorter when the SOA was 900 ms than when the SOA was 1200 ms. Further a- nalysis indicated that inhibition was negatively impaired on the llth -13th and the 20th -22th days of the head-down bed rest and then recovered on the 32th -34th and the 40th -42th day of the rest. After the rest, the inhibition was impaired as well. Conclusions Since perform cognitive process is prolonged during the 45 d of -6~ head-down bed rest the SOA is needed longer to result in the inhibition of return. Moreover, inhibition of return is affected during the early stage of head-down bed rest and the recovery stage after head-down bed rest. There are changes in IOR from impaired, down bed rest adaptive to recovered process during the 45-days of - 6° head-