ActaAstronautica2013,84: 81–87
Effects of 45-day -6°Head-down Bed Rest on the Time-based Prospective Memory
SiYi Chen a,b, RenLai Zhou a,b,*, LiChaoXiua,b, ShanGuang Chen c, XiaoPing Chen c, Cheng Tan c
a Beijing Key Lab of Applied Experimental Psychology, School of Psychology, Beijing Normal University,Beijing100875, China
b State Key Laboratory of Cognitive Neuroscience and Learning, Beijing Normal University, Beijing100875,China
cChina Astronaut Research and Training Center, Beijing 100094, China
Abstract:The research explored the effects of 45-day -6°head-down bed rest (HDBR) simulation of microgravity on the time-based prospective memory (PM) with 16 males. The time-based prospective memory task was performed on 2 d before HDBR, on the 11th, 20th, 32nd, 40th days during HDBR, and on the 8th day after HDBR, and subjects' anxiety and depression feelings were recorded simultaneously using Beck Anxiety Inventory (BAI) and Beck Depression Inventory (BDI). The results demonstrated that it showed decreased accuracy of PM responses and frequency of clock checks during and after bed rest; long term bed rest did not induce significant emotional changes. The deficit of prospective memory performance induced by long term HDBR may result from a lack of aerobic physical activity or changes in the prefrontal cortex, but it remains to be determined.
Key words:weightlessness simulation; head-down bed rest;time-based prospective memory
Table 1
Proportion correct in 3-s and 19-s windows, deviations in responding from target time within a 19-s window and the rates of missed and late errors.
| Response window | PRE-HDBR | HDBR11 | HDBR20 | HDBR32 | HDBR40 | POST-HDBR | F |
| Mean | SD | Mean | SD | Mean | SD | Mean | SD | Mean | SD | Mean | SD |
| 3s |
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| Proportion correct | 0.67 | 0.27 | 0.48 | 0.24 | 0.35 | 0.23 | 0.54 | 0.17 | 0.42 | 0.23 | 0.40 | 0.22 | 2.43* |
| 19s |
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| Proportion correct | 0.85 | 0.17 | 0.79 | 0.17 | 0.77 | 0.16 | 0.71 | 0.24 | 0.75 | 0.19 | 0.73 | 0.18 | 1.24 |
| Deviations from target time (s) | 1.90 | 0.39 | 2.81 | 0.52 | 2.73 | 0.55 | 2.56 | 0.62 | 2.69 | 0.56 | 2.62 | 0.33 | 6.99** |
| Missed error | 0.41 | 0.44 | 0.39 | 0.42 | 0.36 | 0.39 | 0.50 | 0.45 | 0.42 | 0.36 | 0.30 | 0.36 | 0.80 |
| Late error | 0.59 | 0.44 | 0.61 | 0.42 | 0.64 | 0.39 | 0.50 | 0.45 | 0.58 | 0.36 | 0.70 | 0.36 | 0.73 |
Note. dfs for F values are 5 and 75. PRE-HDBR: before bed rest; HDBR11: 11th day of bed rest; HDBR20: 20th day of bed rest; HDBR32: 32nd day of bed rest; HDBR40: 40th day of bed rest; POST-HDBR: after bed rest. * P<0.05, ** P<0.01
Table 2
Percentage of participants for each category of response (%, N=16).
| Category of response | PRE-HDBR | HDBR11 | HDBR20 | HDBR32 | HDBR40 | POST-HDBR |
| 0 | 0 | 12.5 | 18.8 | 0 | 12.5 | 12.5 |
| 1 | 31.3 | 31.3 | 56.3 | 37.5 | 50 | 56.3 |
| 2 | 37.5 | 56.3 | 25 | 62.5 | 37.5 | 31.3 |
| 3 | 31.3 | 0 | 0 | 0 | 0 | 0 |
Note. PRE-HDBR: before bed rest; HDBR11: 11th day of bed rest; HDBR20: 20th day of bed rest; HDBR32: 32nd day of bed rest; HDBR40: 40th day of bed rest; POST-HDBR: after bed rest.
Table 3
Number of times clock-checking behavior for four quartiles of the minute preceding target time and total test period.
| Response window | PRE-HDBR | HDBR11 | HDBR20 | HDBR32 | HDBR40 | POST-HDBR | F |
| Mean | SD | Mean | SD | Mean | SD | Mean | SD | Mean | SD | Mean | SD |
| Quartile |
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| 1-15s | 0.44 | 0.51 | 0.38 | 0.50 | 0.31 | 0.48 | 0.38 | 0.50 | 0.44 | 0.51 | 0.31 | 0.48 | 0.19 |
| 2-15s | 0.75 | 0.45 | 0.63 | 0.50 | 0.56 | 0.51 | 0.56 | 0.51 | 0.63 | 0.50 | 0.50 | 0.52 | 0.43 |
| 3-15s | 0.94 | 0.57 | 0.88 | 0.50 | 0.63 | 0.50 | 0.75 | 0.45 | 0.56 | 0.51 | 0.63 | 0.50 | 1.49 |
| 4-15s | 3.63 | 0.81 | 2.50 | 0.82 | 1.88 | 0.62 | 2.69 | 0.79 | 2.00 | 0.89 | 1.88 | 0.81 | 12.83* |
| Total | 6.50 | 0.89 | 4.94 | 0.68 | 4.06 | 0.68 | 4.81 | 1.05 | 4.13 | 1.02 | 4.19 | 1.11 | 15.51* |
Note. dfs for F values are 5 and 75. PRE-HDBR: before bed rest; HDBR11: 11th day of bed rest; HDBR20: 20th day of bed rest; HDBR32: 32nd day of bed rest; HDBR40: 40th day of bed rest; POST-HDBR: after bed rest.
* P<0.001
Table 4
Scores of short-term memory test, Beck Anxiety Inventory (BAI) and Beck Depression Inventory (BDI).
| Response window | PRE-HDBR | HDBR11 | HDBR20 | HDBR32 | HDBR40 | POST-HDBR | F |
| Mean | SD | Mean | SD | Mean | SD | Mean | SD | Mean | SD | Mean | SD |
| Short-term memory | 4.31 | 0.35 | 4.11 | 0.50 | 4.03 | 0.64 | 4.29 | 0.65 | 4.25 | 0.38 | 4.29 | 0.56 | 1.31 |
| BAI | 26.31 | 1.96 | 29.25 | 4.33 | 28.25 | 5.56 | 27.94 | 3.79 | 29.19 | 5.73 | 31.44 | 9.80 | 2.09 |
| BDI | 2.75 | 4.44 | 4.38 | 5.33 | 3.63 | 4.53 | 4.31 | 7.48 | 5.25 | 9.46 | 4.44 | 7.37 | 0.55 |
Note. dfs for F values are 5 and 75. PRE-HDBR: before bed rest; HDBR11: 11th day of bed rest; HDBR20: 20th day of bed rest; HDBR32: 32nd day of bed rest; HDBR40: 40th day of bed rest; POST-HDBR: after bed rest.
45天-6°头低位卧床对基于时间的前瞻记忆的影响
陈思佚a,b，周仁来a,b,*，修利超a,b，陈善广c，陈晓萍c，谈成c
a北京师范大学北京应用试验心理重点实验室北京 100875
b北京师范大学认知神经科学与学习国家重点实验室北京 100875
c中国航天员科研训练中心北京 100094
?? 该研究探讨45天-6°头低位卧床（HDBR）模拟微重力条件对16名男性被试基于时间的前瞻记忆的影响。被试在卧床前2天、卧床第11天、20天、32天和40天以及卧床后第8天完成基于时间的前瞻记忆任务，使用贝克焦虑量表（BAI）和贝克抑郁量表（BDI）同步记录被试的焦虑和抑郁情绪。结果表明，前瞻记忆反应的正确率和检查时间的频率在卧床期间和卧床后下降，长时期的卧床没有引发显著的情绪变化。有氧身体活动的缺乏或者前额叶皮质的变化可能是导致基于时间的前瞻记忆伴随长时期HDBR下降的原因，但是这些影响因素有待进一步的研究。
