Advanced MRI Section, LFMI, NINDS, National Institutes of Health, Bethesda, MD 20982-1065, USA.
Neuroimage. 2010 May 15;51(1):102-11. doi: 10.1016/j.neuroimage.2010.01.092. Epub 2010 Feb 1.
Knowledge about the intrinsic functional architecture of the human brain has been greatly expanded by the extensive use of resting-state functional magnetic resonance imaging (fMRI). However, the neurophysiological correlates and origins of spontaneous fMRI signal changes remain poorly understood. In the present study, we characterized the power modulations of spontaneous magnetoencephalography (MEG) rhythms recorded from human subjects during wakeful rest (with eyes open and eyes closed) and light sleep. Through spectral, correlation and coherence analyses, we found that resting-state MEG rhythms demonstrated ultraslow (<0.1 Hz) spontaneous power modulations that synchronized over a large spatial distance, especially between bilaterally homologous regions in opposite hemispheres. These observations are in line with the known spatio-temporal properties of spontaneous fMRI signals, and further suggest that the coherent power modulation of spontaneous rhythmic activity reflects the electrophysiological signature of the large-scale functional networks previously observed with fMRI in the resting brain.
静息态功能磁共振成像（fMRI）的广泛应用极大地拓展了人们对人脑内在功能结构的认识。然而，自发 fMRI 信号变化的神经生理学相关性和起源仍知之甚少。在本研究中，我们描述了清醒静息（睁眼和闭眼）和轻度睡眠期间从人类受试者记录的自发脑磁图（MEG）节律的功率调制。通过频谱、相关和相干分析，我们发现静息状态 MEG 节律表现出超慢（<0.1 Hz）的自发功率调制，在很大的空间距离上同步，特别是在对侧半球的双侧同源区域之间。这些观察结果与已知的自发 fMRI 信号的时空特性一致，并进一步表明自发节律活动的相干功率调制反映了先前在静息大脑中使用 fMRI 观察到的大规模功能网络的电生理特征。
