Holländer I, Petsche H, Dimitrov L I, Filz O, Wenger E
Institute of Information Processing, Austrian Academy of Sciences, Wien.
Brain Topogr. 1997 Spring;9(3):177-89. doi: 10.1007/BF01190387.
Up until recently, neurology was dominated by localisatory thinking. Language and other so-called "centers" were considered to be centers of command controlling the respective functions. Today, there is general agreement that, instead, for every brain function numerous brain regions must act together. For the exploration of these manifold topographic cooperations produced by cognitive tasks, coherence of long-term EEG periods proved to be a proficient parameter for the representation of functionally essential connections. Because of the unequivocal meaningfulness of absolute coherence values, instead, only the signs of significant differences between coherence values during cognitive tasks and periods of EEG at rest before and after the task were considered for all possible electrode pairings and charted on schematic maps of the brain. In addition, the signs of significant changes of amplitude were entered. This procedure was performed for each of 6 frequency bands and for the 19 electrodes of the 10/20 system, thus yielding 171 possible plus or minus values for coherence and 19 for amplitude, respectively. The positions of the electrodes were marked by an MRI contrast medium. After the EEG, MRI examination was performed. The MRI data were segmented and the cortex was mapped onto a plane using a method similar to cartography. The exact electrode positions are registered from a similarly obtained map of the scalp and the electrode position pattern is used as basis for the coherence graphs. A detailed map of the cortex based on the segmented MRI data with the electrode positions marked is provided as a reference enabling allocation of the electrodes to the cortical structures. The usefulness of this procedure is demonstrated with a single subject by means of different cognitive tasks including musical thinking.
直到最近，神经学一直受定位思维主导。语言和其他所谓的“中枢”被认为是控制各自功能的指挥中心。如今，人们普遍认同的是，每种脑功能都必须有众多脑区共同发挥作用。为了探究由认知任务产生的这些多样的地形学协作，长期脑电图周期的相干性被证明是表示功能上重要连接的一个有效参数。由于绝对相干值具有明确的意义，因此，对于所有可能的电极对，只考虑认知任务期间与任务前后脑电图静息期相干值之间显著差异的符号，并绘制在大脑示意图上。此外，还记录了振幅显著变化的符号。此过程针对10/20系统的6个频段中的每个频段以及19个电极进行，从而分别产生171个可能的相干性正负值和19个振幅值。电极位置用磁共振成像造影剂标记。脑电图检查后，进行磁共振成像检查。对磁共振成像数据进行分割，并使用类似于制图的方法将皮质映射到一个平面上。从类似获得的头皮图中记录精确的电极位置，并将电极位置模式用作相干性图的基础。提供一幅基于分割后的磁共振成像数据并标记了电极位置的详细皮质图作为参考，以便将电极分配到皮质结构。通过包括音乐思维在内的不同认知任务，对一名受试者证明了该程序的有效性。
