Dale A M, Halgren E
Massachusetts General Hospital Nuclear Magnetic Resonance Center, 149 13th Street, Charlestown, MA 02129, USA.
Curr Opin Neurobiol. 2001 Apr;11(2):202-8. doi: 10.1016/s0959-4388(00)00197-5.
Functional magnetic resonance imaging (fMRI) and positron emission tomography measure local changes in brain hemodynamics induced by cognitive or perceptual tasks. These measures have a uniformly high spatial resolution of millimeters or less, but poor temporal resolution (about 1s). Conversely, electroencephalography (EEG) and magnetoencephalography (MEG) measure instantaneously the current flows induced by synaptic activity, but the accurate localization of these current flows based on EEG and MEG data alone remains an unsolved problem. Recently, techniques have been developed that, in the context of brain anatomy visualized with structural MRI, use both hemodynamic and electromagnetic measures to arrive at estimates of brain activation with high spatial and temporal resolution. These methods range from simple juxtaposition to simultaneous integrated techniques. Their application has already led to advances in our understanding of the neural bases of perception, attention, memory and language. Further advances in multi-modality integration will require an improved understanding of the coupling between the physiological phenomena underlying the different signal modalities.
功能磁共振成像（fMRI）和正电子发射断层扫描可测量由认知或感知任务引起的脑血流动力学局部变化。这些测量方法具有统一的高空间分辨率，可达毫米或更小，但时间分辨率较差（约1秒）。相反，脑电图（EEG）和脑磁图（MEG）可即时测量由突触活动引起的电流，但仅基于EEG和MEG数据对这些电流进行准确定位仍是一个未解决的问题。最近，已经开发出一些技术，在通过结构MRI可视化的脑解剖结构背景下，使用血流动力学和电磁测量方法来获得具有高空间和时间分辨率的脑激活估计。这些方法从简单并列到同时集成技术不等。它们的应用已经在我们对感知、注意力、记忆和语言的神经基础的理解方面取得了进展。多模态整合的进一步进展将需要更好地理解不同信号模态背后的生理现象之间的耦合。
