Scarff Carrie J, Reynolds Angela, Goodyear Bradley G, Ponton Curtis W, Dort Joseph C, Eggermont Jos J
Department of Psychology, University of Calgary, Calgary, Alberta, Canada, T2N 1N4.
Neuroimage. 2004 Nov;23(3):1129-42. doi: 10.1016/j.neuroimage.2004.07.035.
We acquired simultaneous high-field (3 T) functional magnetic resonance imaging (fMRI) and high-density (64- and 128-channel) EEG using a sparse sampling technique to measure auditory cortical activity generated by right ear stimulus presentation. Using dipole source localization, we showed that the anatomical location of the grand mean equivalent dipole of auditory evoked potentials (AEPs) and the center of gravity of fMRI activity were in good agreement in the horizontal plane. However, the grand mean equivalent dipole was located significantly superior in the cortex compared to fMRI activity. Interhemispheric asymmetry was exhibited by fMRI, whereas neither the AEP dipole moments nor the mean global field power (MGFP) of the AEPs showed significant asymmetry. Increasing the number of recording electrodes from 64 to 128 improved the accuracy of the equivalent dipole source localization but decreased the signal-to-noise ratio (SNR) of MR images. This suggests that 64 electrodes may be optimal for use in simultaneous recording of EEG and fMRI.
我们采用稀疏采样技术同时采集了高场强（3T）功能磁共振成像（fMRI）和高密度（64通道和128通道）脑电图（EEG），以测量右耳刺激呈现所产生的听觉皮层活动。使用偶极子源定位，我们发现听觉诱发电位（AEP）的总体平均等效偶极子的解剖位置与fMRI活动的重心在水平面上高度一致。然而，总体平均等效偶极子在皮层中的位置比fMRI活动明显更高。fMRI表现出半球间不对称性，而AEP的偶极矩和平均全局场功率（MGFP）均未显示出明显的不对称性。将记录电极数量从64个增加到128个提高了等效偶极子源定位的准确性，但降低了磁共振图像的信噪比（SNR）。这表明64个电极可能是同时记录EEG和fMRI的最佳选择。
