Tuunanen Pasi I, Kavec Martin, Jousmäki Veikko, Usenius Jussi-Pekka, Hari Riitta, Salmelin Riitta, Kauppinen Risto A
Department of Biomedical NMR and National Bio-NMR Facility, University of Kuopio, Finland.
Neuroimage. 2003 Aug;19(4):1778-86. doi: 10.1016/s1053-8119(03)00256-8.
The characteristics of blood oxygenation level-dependent (BOLD) fMRI and magnetoencephalographic (MEG) responses to vibrotactile stimuli in humans were studied and compared. The stimuli, presented with interstimulus intervals (ISIs) ranging from 1 to 5 s, yielded highly reproducible MEG responses, with current dipoles in the primary somatosensory (SI) cortex in all subjects. BOLD fMRI responses to similar stimuli showed substantial intrasubject variation in the activation sites around the SI cortex. BOLD responses were detected in all subjects in the secondary somatosensory (SII) cortices as well, with comparable BOLD response amplitudes to those in the SI cortex. Current dipoles, used to model the MEG signals, were stronger at longer ISIs than shorter ISIs. The BOLD response amplitudes did not show a similar dependence on ISI, but the activated brain area was larger when longer ISIs or longer stimuli were applied. Our results support the view that combined use of brain mapping methods provides complementary information and should be considered in functional brain examinations.
对人类血液氧合水平依赖（BOLD）功能磁共振成像（fMRI）和脑磁图（MEG）对振动触觉刺激的反应特征进行了研究和比较。刺激以1至5秒的刺激间隔（ISI）呈现，产生了高度可重复的MEG反应，所有受试者的电流偶极子均位于初级体感（SI）皮层。BOLD fMRI对类似刺激的反应显示，SI皮层周围的激活部位在受试者内部存在显著差异。在所有受试者的次级体感（SII）皮层中也检测到了BOLD反应，其BOLD反应幅度与SI皮层中的相当。用于模拟MEG信号的电流偶极子在较长ISI时比在较短ISI时更强。BOLD反应幅度并未显示出对ISI的类似依赖性，但当应用较长的ISI或较长的刺激时，激活的脑区更大。我们的结果支持这样一种观点，即联合使用脑图谱方法可提供互补信息，在功能性脑检查中应予以考虑。
