Oishi N, Mima T, Ishii K, Bushara K O, Hiraoka T, Ueki Y, Fukuyama H, Hallett M
Human Brain Research Center, Kyoto University Graduate School of Medicine, Kyoto 606-8507, Japan.
Neuroimage. 2007 Jul 15;36(4):1301-12. doi: 10.1016/j.neuroimage.2007.04.030. Epub 2007 Apr 25.
To clarify the physiological significance of task-related change of the regional electroencephalogram (EEG) rhythm, we quantitatively evaluated the correlation between regional cerebral blood flow (rCBF) and EEG power. Eight subjects underwent H2 15O positron emission tomography scans simultaneously with EEG recording during the following tasks: rest condition with eyes closed and open, self-paced movements of the right and left thumb and right ankle. EEG signals were recorded from the occipital and bilateral sensorimotor areas. Cortical activation associated with EEG rhythm generation was studied by the correlation between rCBF and EEG power. There were significant negative correlations between the sensorimotor EEG rhythm at 10-20 Hz on each side and the ipsilateral sensorimotor rCBF and between the occipital EEG rhythm at 10-20 Hz and the occipital rCBF. The occipital EEG rhythm showed a positive correlation with the bilateral medial prefrontal rCBF, while the right sensorimotor EEG rhythm showed a positive correlation with the left prefrontal rCBF. In conclusion, decrease in the regional EEG rhythm at 10-20 Hz might represent the neuronal activation of the cortex underlying the electrodes, at least for the visual and sensorimotor areas. The neural network including the prefrontal cortex could play an important role to generate the EEG rhythm.
为阐明局部脑电图（EEG）节律与任务相关变化的生理意义，我们定量评估了局部脑血流（rCBF）与EEG功率之间的相关性。八名受试者在以下任务期间同时接受了H2 15O正电子发射断层扫描和EEG记录：闭眼和睁眼的静息状态、左右拇指和右踝的自主运动。EEG信号从枕叶和双侧感觉运动区记录。通过rCBF与EEG功率之间的相关性研究了与EEG节律产生相关的皮质激活。每侧10-20Hz的感觉运动EEG节律与同侧感觉运动rCBF之间以及枕叶10-20Hz的EEG节律与枕叶rCBF之间存在显著负相关。枕叶EEG节律与双侧内侧前额叶rCBF呈正相关，而右侧感觉运动EEG节律与左侧前额叶rCBF呈正相关。总之，10-20Hz局部EEG节律的降低可能代表电极下方皮质的神经元激活，至少对于视觉和感觉运动区是如此。包括前额叶皮质在内的神经网络可能在产生EEG节律中起重要作用。
