摘要
本研究将选择/无选法范式和运转记忆任务范式相结合,借助行为实验和ERP技术,采用两位数乘法估算任务,要求被试先进行运转记忆任务,再进行乘法估算任务。通过考察有、无负荷条件对估算策略运用的影响,来揭示中央执行负荷对算术策略运用影响的心理机制以及神经基础。结果发现:(1)中央执行负荷对策略选择的反应时和正确率都有着显著影响,有负荷条件下策略选择的反应时长、正确率低;而对于策略执行,中央执行负荷对其反应时有着显著影响,有负荷条件下策略执行任务反应时长,但对正确率没有显著影响。(2)对于策略选择,有负荷条件较无负荷条件能激发更强的N100,其潜伏期也更长。有负荷条件激活了更强的P220,其潜伏期也更长。此外,有负荷条件还激活了更强的P300,但其潜伏期与无负荷条件下的差异未达到显著水平。(3)对于策略执行,有负荷条件较无负荷条件激发了更强的N100,其潜伏期也更长。有、无负荷对N400的波峰及峰潜时没有显著影响。结论:个体的算术策略运用表现受到中央执行负荷的明显影响,施加负荷会阻碍个体对数字信息的加工比较过程,但在长时记忆信息提取上这种阻碍作用相对较弱。
In this research, we combined choice/no choice paradigm and running-memory task to explore the relationship between central executive load and arithmetic strategy utilization in two-digit arithmetic estimation tasks and the neural mechanism of the relationship with the help of behavioral cognitive measures and event-related brain potentials(ERPs) technique. Major results are as follows:(1)Central executive load had a significant effect on strategy chosen, both on reaction time and accuracy. In load condition, reaction time of strategy choice were prolonged, the accuracy of strategy chosen declined.(2)ERPs data show that: central executive load elicited a larger N100, and the latency was longer on the left brain. Central executive load elicited a larger P220, the latency was also longer. Central executive load elicited a larger P300, but the latency was not reaching a different level.(3)Central executive load had a significant effect on the reaction time of strategy execution. However, the effect on accuracy was not significant. In load condition, reaction time of strategy execution was prolonged.(4) ERPs data show that: central executive load elicited a larger N100, the latency was also longer. Central executive load elicited a larger N400 on the right brain, but the latency was not reaching a different level. Conclusions are drawn as follows: Central executive load has an effect on arithmetic strategy chosen utilization, individuals' performances in no load condition were better.
引文