Tesche C D, Uusitalo M A, Ilmoniemi R J, Kajola M J
Low Temperature Laboratory, Helsinki University of Technology, Espoo, Finland.
Brain Res Cogn Brain Res. 1995 Oct;2(4):243-9. doi: 10.1016/0926-6410(95)90015-2.
We report on the determination of detailed spectra for simultaneously active sources of spontaneous neuronal activity in humans directly from data recorded with a whole-scalp 122-channel magnetometer array. Subjects rested with eyes open and performed two contrasting mental imagery tasks: the imagination of the self-performance of a motor activity and the silent generation of a chain of words. A novel analysis technique, frequency-domain signal-space projection (FDSSP) was utilized to determine the temporal and spectral characteristics of spontaneous brain activity at specific cortical sites. Although intersubject differences were significant, spectra for individual subjects contained task-dependent features which were reproducible over successive 20-s epochs. This result supports the concept of multiple sources of spontaneous cortical activity and suggests that detailed spectra of localized oscillatory activity obtained non-invasively with magnetoencephalographic arrays may provide a useful characterization of cortical involvement in mental imagery.
我们报告了直接从全头皮122通道磁力计阵列记录的数据中确定人类自发神经元活动同时活跃源的详细频谱。受试者睁眼休息并执行两项对比性的心理意象任务：想象进行一项运动活动以及默默生成一串单词。一种新颖的分析技术，即频域信号空间投影（FDSSP），被用于确定特定皮质部位自发脑活动的时间和频谱特征。尽管个体间差异显著，但个体受试者的频谱包含与任务相关的特征，这些特征在连续的20秒时段内是可重复的。这一结果支持了自发皮质活动多源的概念，并表明通过脑磁图阵列非侵入性获得的局部振荡活动的详细频谱可能为皮质在心理意象中的参与提供有用的特征描述。
