不同记忆负荷对事件相关电位—P300的影响

我们研究了不同记忆负荷条件下,ERP-P_(300)变化的规律性和特点及ERP-P_(300)与脑力负荷难度之间的关系。在三种脑力作业时,要求受试者记忆2、4、6位随机数字。结果表明,1、随着记忆数字增加,P_(300)波幅相应增大,三种记忆作业P_(300)波幅之间均有显著性差异。2、记忆错误率和记忆难度主观评价值,亦随着记忆数字增加而增大,且在三种记忆作业之间均有显著性差异。3、P_(300)波幅和记忆难度主观评价值之间相关分析表明呈正相关(P<0.01)。我们建议,P_(300)波幅测量可以作为评价脑力负荷的一项客观指标。

Effects of Different Mental Tasks on P300 Component of Event-related Potentials

We studied the regularity and the characteristic of changes in ERP-P300and the relationship between ERP-P300 and the difficulty of mental task in dif-ferent levels of memory load.In three mental tasks,subjects of the studywere requested to remember randomized numbers of 2,4 and 6 digits,respectively,Results showed that:1.With the increase of memory task,theamplitudes of P300 were increased proportionally,and there were apparentdifferences among the P300 amplitudes of three memory tasks;2.The memo-ry error rate and self-evaluation of task difficulty increased with the increasingof digits of memory load,and there were significant differences among thethree memory tasks;3.The correlation between P300 amplitudes andselfevaluation of task difficulty showed a positive relationship.It is suggestedthat the measurement of P300 amplitude can be considered as an objective in-dex for evaluating mental loads.