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基于在脑电频率范围内的磁场剌激对脑过程可能有调制作用的假设，并在已取得结果的基础上，本文在２２名正常被试者中比较了５Ｈｚ和２０Ｈｚ的磁场剌激对进行选择反应（ＳＲＰ）和选择心算（ＳＭＡ）时脑反应的影响。在选择反应作业中，要求被试者对听到的奇数进行拨开关反应而忽略偶数，在选择心算时则要求仅对听到的奇数进行连续累加。磁场强度２ｍＴ，剌激时间２０ｍｉｎ。评价脑反应的指标为事件关联电位（ＥＲＰｓ）、事件关联功谱（ＥＲＰＳＤ）和相干幅谱（ＣｏｈＡ）。主要结果如下：（１）５Ｈｚ磁场剌激后ＳＭＡ的ＥＲＰｓ中正慢波增大，ＳＲＰ的在后脑区的Ｐ３００潜伏期缩短，ＳＭＡ靶信号的ＥＲＰＳＤ中θ、α脑电活动的功率增强，而ＳＲＰ的ＥＲＰＳＤ中δ活动增强，同时高频活动显著下降；（２）２０Ｈｚ磁场剌激后，无上述变化，但ＳＭＡ的ＣｏｈＡ中高于１０Ｈｚ的相干幅增强。考虑到Ｐ３００潜伏期和低、高频脑电活动的生理心理意义，以及认知活动中正慢波可能和与注意有关的主动抑制过程有关，上述结果提示：５Ｈｚ磁场剌激后脑处于较佳的功能状态，而２０Ｈｚ磁场的作用则可能影响脑的高频活动本身，其意义尚需进一步研究
Based on the hypothesis that there may be a modulating effect of magnetic stimulation on brain processes in the range of EEG frequencies and on the basis of the results obtained, magnetic resonance stimuli at 5 Hz and 20 Hz were compared among 22 normal subjects The effects of brain response when SRP and SMA were selected. In the choice of reaction operation, subjects were asked to dial the switch on the odd number to ignore the even number, in the choice of mental arithmetic requires only the odd number of consecutive hearings. Magnetic field strength 2mT, stimulating time 20min. The indicators for evaluating brain response were event-related potentials (ERPs), event-related spectrum (ERPSD) and coherence spectrum (Coh-A). The main results are as follows: (1) Positive and slow waves of SMA ERPs increased after stimulated by 5Hz magnetic field, while P300 latency of SRP in the posterior brain region shortened. The power of θ, α EEG activity in ERPSD of SMA target signal increased. The activity of δ increased in ERPSD, while the activity of high frequency decreased significantly. (2) After 20 Hz magnetic field stimulation, there was no such change, but the coherence amplitude higher than 10 Hz in CohA of SMA increased. Taking into account the P300 latency and low and high frequency EEG activity of the physiological and psychological significance, as well as positive and negative cognitive activity may be related to the attention and active suppression process, the above results suggest that: 5Hz magnetic field stimulation of the brain in a better functional state , While the role of 20Hz magnetic field may affect the brain’s high-frequency activity itself, its significance needs further study