中文摘要：

目的：利用脑磁图（MEG）合成孔径磁场测量（SAM）时频分析法研究正常健康受试者运动磁场的变化情况。方法：17例健康受试者给予纯音刺激，受试者听到声音后右手食指触压按键感应器。以声音触发为基点进行平均，选择触发点后的波形进行分析。结果：所有17例受试者定位大脑皮层中央前回，与运动皮层解剖位置一致，在听到触发后的400～550ms之间有比较明显的密集激活，占总激活数的74％（34／46）。结论：MEG的SAM时-频分析法能够确切地描述皮层神经兴奋活动在时频域的能量变换情况。

英文摘要：

Objective：Synthetic aperture magnetometry（SAM） was used to analyse the motor field of response in healthy subjects by magnetoencephalograph. Methods： 17 subjects were given auditory stimulation and were then asked to press the button with the right forefinger. The brain activities were averaged by the sound trigger. SAM was used to analyze,the waves around trigger. Results：The SAM results were localized in the precentral motor cortex in accordance with the anatomical position of motor cortex. Between 400- 550 ms after sound trigger there was more obvious trigger intensive activation（34/46）. Conclusion： SAM time-frequency analysis method with MEG can accurately describe the activities in the cortical excitability.