利用128导事件相关电位技术,对19名正常被试在言语、峰鸣声和音乐刺激上产生的脑电早期外源性成分N1进行了考察。实验结果发现,在音素条件和蜂呜声条件下,左侧额叶N1波幅显著高于右侧。偶极子溯源分析发现音素条件和蜂鸣声条件下的偶极子都位于左脑额叶,而音乐条件下的两个偶极子位于右脑额叶。证明范畴属性对信号加工大脑半球优势的影响在加工的早期就开始发挥作用;
Speech and nonspeech ~unds are processed in different cortical areas but whether the dissociation is reflected before the MMN window is not established. With high-density event-related potentials, the --100ms event-related potentials ( N1 ) were recorded to investigate whether the neural response was different between speech and nonspeech sounds at an early stage. Our stimuli included phonemes, hums and musical notes. The results showed that compared with piano chords, N1 were left lateralized under the phoneme and hum conditions. Source analysis also demonstrated that the dipole was located in the left frontal scalp sites under the phoneme and hum conditions. And two dipoles in the right frontal sites contributed to the topography of the piano chord condition. These results suggest that the stimulus properties influence the brain processing laterality at a very early stage.