注意状态对听觉事件相关电位及脑电功率的影响

Effect of different attention states on auditory ERP and EEG power

目的 研究正常智能受试者在不同注意状态下 ,其听觉事件相关电位 (ERP)及脑电功率的变化 ,从而探讨不同注意状态对ERP及脑电功率的影响。方法 分别记录受试者在被动注意、主动注意并计数及主动注意不计数三种状态下 ,经Oddball模式刺激后的脑电信号 ,并比较其ERP的峰 峰幅值及潜伏期 ,同时分析脑电功率谱在不同注意状态下的变化。结果 当本研究中受试者处于主动注意并计数状态时 ,其P2 -N1峰 峰幅值最小 ,而P3 -N2 峰 峰幅值最大 ,而且此时频率为 10Hz的脑电功率明显增大 ;另外受试者在三种注意状态下的ERP潜伏期间的差异均无显著性意义。结论 P2 -N1峰 峰幅值减小及P3 -N2 峰 峰幅值增大显示大脑在不同注意状态下其注意资源的分配变化情况 ,脑电功率的增加则提示认知与记忆过程需要更多的能量消耗 ;ERP潜伏期则不易受注意状态变化的影响。

Objective To study the effect of different attention states on auditory ERP and EEG power in normal subjects. Methods In three different states such as passive attention,active attention with target counting and active attention without target counting,EEG were recorded using oddball paradigm in 8 normal subjects while the test tones were presented;Then the peak-peak amplitude and latency of ERP were evaluated and the EEG power spectra were observed. Results The condition of active attention with target counting resulted in the smallest peak-peak amplitude of P 2-N 1 and the largest one of P 3-N 2,and it led to the increment of EEG power at the frequency of 10Hz,while the latencies did not differ among the three different attention states. Conclusion Reduced P 2-N 1 amplitude and increased P 3-N 2 amplitude reflected the allocation changes of attention resource in different states,and increased EEG power reflected more energy consumption in the process of recognition and memory,but the latency was relatively stable and not affected significantly by subject's attention condition.