Ritter Petra, Moosmann Matthias, Villringer Arno
Berlin NeuroImaging Center and Charité, Universitätsmedizin Berlin, Germany.
Hum Brain Mapp. 2009 Apr;30(4):1168-87. doi: 10.1002/hbm.20585.
Similar to the posterior alpha rhythm, pericentral (Rolandic) EEG rhythms in the alpha and beta frequency range are referred to as "idle rhythms" indicating a "resting state" of the respective system. The precise function of these rhythms is not clear. We used simultaneous EEG-fMRI during a bimanual motor task to localize brain areas involved in Rolandic alpha and beta EEG rhythms. The identification of these rhythms in the MR environment was achieved by a blind source separation algorithm. Rhythm "strength", i.e. spectral power determined by wavelet analysis, inversely correlated most strongly with the fMRI-BOLD signal in the postcentral cortex for the Rolandic alpha (mu) rhythm and in the precentral cortex for the Rolandic beta rhythm. FMRI correlates of Rolandic alpha and beta rhythms were distinct from those associated with the posterior "classical" alpha rhythm, which correlated inversely with the BOLD signal in the occipital cortex. An inverse correlation with the BOLD signal in the respective sensory area seems to be a general feature of "idle rhythms".
与后头部阿尔法节律相似，中央旁（罗兰）脑电图在阿尔法和贝塔频率范围内的节律被称为“静息节律”，表明相应系统处于“休息状态”。这些节律的确切功能尚不清楚。我们在一项双手运动任务期间使用同步脑电图 - 功能磁共振成像来定位与罗兰阿尔法和贝塔脑电图节律相关的脑区。通过盲源分离算法在磁共振环境中识别这些节律。节律“强度”，即通过小波分析确定的频谱功率，对于罗兰阿尔法（μ）节律而言，与中央后回皮层中的功能磁共振成像 - 血氧水平依赖信号呈最强负相关，对于罗兰贝塔节律而言，与中央前回皮层中的功能磁共振成像 - 血氧水平依赖信号呈最强负相关。罗兰阿尔法和贝塔节律的功能磁共振成像相关性与那些与后头部“经典”阿尔法节律相关的相关性不同，后者与枕叶皮层中的血氧水平依赖信号呈负相关。与相应感觉区域中的血氧水平依赖信号呈负相关似乎是“静息节律”的一个普遍特征。
