头低位卧床模拟失重对知觉正确性和冲突控制能力的影响

Effects of Head-down Bed Rest Stimulated Weightlessness on Perceptual Accuracy and Conflict Control Function

目的探究45 d-6°头低位卧床中知觉正确性和冲突控制能力受到的影响和变化规律。方法采用头低位卧床模拟失重,选取视觉后向掩蔽任务和刺激-反应冲突任务,在卧床实验6个不同阶段(卧床前第6天,卧床中第11,20,30和40天,以及卧床后第8天)对16名志愿者进行重复测试。结果在知觉正确性测试中,志愿者在卧床第11天的正确率显著提高(P>0.05),在卧床第32天时达到并维持在一个较高的水平直至卧床后第8天最后一次测试。在刺激-反应冲突任务中,在卧床第32天测试中出现显著的促进作用(P>0.05),并在起床后明显下降。结论头低位卧床对认知功能不会造成明显损害,甚至可能有促进作用;知觉正确性和反应协调性的变化趋势在卧床早期具有一定的相似性;在卧床结束后冲突控制能力降低,但知觉正确性未受影响。

Objective To investigate the influence of 45 d of-6° head-town bed rest（HDBR） on perceptual accuracy and conflict control function. Methods Sixteen healthy subjects participated in this experiment. Six test sessions were conducted： on the 6th day before bed rest, on the llth, 20th, 32nd and 40th day of bed rest and on the 8th day of recovery after HDBR. The visual backward masking task and the stimulus-response conflict task were adopted to test the subjects＇ perceptual accuracy and conflict control function separately. Results In the visual backward masking task, the accuray on the 11 th day of HDBR was increased significantly as compared with that in pre-HDBR （ P 〉 0. 05 ）. And the performance was reached to a higher level on the 32nd day of HDBR, following a period of performance stabilization until post-HDBR. In the stimulus-response conflict task, there was a significant improvement on the 32nd day of HDBR（P 〉 0.05 ）. But the performance was damaged apparently in post-HDBR. Conclusion Simulated weightlessness is of no significant negative influence on perceptual accuracy and conflict control function; on the contrary, there are some positive effects on these cognitive functions, especially on conflict control function. The pattern of change of perceptual accuracy is similar to the conflict control function on early phase of HDBR. But during the phase of readaptation after HDBR, subjects＇ performance is impaired significantly in conflict control function but not in perceptual accuracy.