靶音识别作业对脑波α段频率涨落特征的影响

Influence of Target-tone Recognition Task on α-band Frequency Fluctuation Characteristics in EEG

目的研究靶音识别作业对脑波α段频率涨落特征的影响及各优势成分的作业相关变化。方法被试为 2 1名右利手、听力及EEG正常男性 ( 2 5～ 35岁 ) ,记录被试闭眼状态下安静及靶音识别作业过程中的 1 2导EEG信号 ,利用脑波频率涨落分析技术分析 8、9、1 0、1 1、1 2、1 3Hz 6个频率成分的优势涨落特征。结果靶音识别作业导致脑波α段频率涨落竞争结构中的主涨落成分向高频方向发展 ,9～ 1 0Hz优势显著下降 ,1 1～ 1 3Hz优势显著增加 ,各频率成分在频率竞争结构中的地位和相互作用改变 ;同时 ,作业相关的优势成分快化与各被试静态EEG有关 ,即围绕静态EEG功谱峰值频率 ,较高频率成分优势几率明显增加 ,较低频率成分优势几率则明显减少。结论靶音识别作业导致脑波α段频率涨落特征的显著改变可能反映了与作业负荷有关的脑一般机能状态的增强 。

Objective To study the influences of target tone recognition task on dominant frequency fluctuation structure of EEG. Method The subjects were 21 healthy right handed male volunteers aged 25～35 years. EEG were recorded with eyes closed during rest or discriminating target tone, and analyzed by means of EEG frequency fluctuation analysis system. Result Under the workload of discriminating target tone, the main dominant components of α band frequency fluctuation of EEG speeded up. The probability of 9～10 Hz dominance decreased significantly, while the probability of 11～13 Hz dominance increased significantly .The correlation between these dominant components in dominant frequency fluctuation competitive structure of EEG changed. Meanwhile, the aforementioned changes have something to do with individual EEG at rest. Around the peak frequency of EEG at rest, the dominant probability of higher frequency components increased obviously, but the dominant probability of lower frequency components decreased obviously. Conclusion During the task, these significant changes of dominant frequency fluctuation competitive structure in EEG might reflect the enhancement of brain activities related to workload. So the method of EEG frequency fluctuation analysis may be helpful in assessing mental workload.