选择反应和选择心算时脑电相干谱的反应特点

EEG Coherence Change during Selective Response and Selective Mental Arithmetic.

为了解不同脑区之间各频率脑电活动的同步性特点及其在认知活动中的变化 ,对2 0名正常被试者在安静及对数字声音信号进行选择反应和选择心算时 9个脑区之间的相干幅谱进行了比较研究。结果 :在进行选择反应作业时 ,额及中央脑区的左右脑之间低频活动 (δ ,θ和α)相干幅值显著增大 ,而后脑区左右脑之间高频活动 ( 2 0～ 70Hz)的相干幅值显著减小 ,与选择反应比 ,选择心算时的主要变化表现为后脑区左右脑之间θ活动和高频活动相干幅值的增大。上述结果表明 ,在进行认知活动时 ,左、右脑相应结构之间的同步联系显著增强且主要是通过低频脑电活动 ,而前、后脑区的不同结构之间则主要表现为脱同步。

To study the basic feature of EEG synchronization among different brain regions and its change during cognitive activities,the EEG coherence amplitude(CohA) spectrum was studied in 20 normal subjects at rest,during seletive response(SRP) and seletive mental arithmetic(SMA).The main resulte were:(1)during SRP,compared with rest condition,the CohA between left and right brain increased significantly at frontal and central brain regions in lower frequency range(1 to 13Hz),but decreased at posterior region in high frequency range(31～70 Hz);(2)During SMA,the CohA of theta activity between left and right brain increased significantly at posterior region relative to that during SRP,along fronto-posterior direction,the CohA of 8～10Hz band increased at F5-C5 but decreased at C6-P6 in 11～13Hz band.These results demonstrated that the degree of synchronization enhanced between corresponding structures on left and right brain mainly in lower frequency EEG activities.