Lutzenberger W, Elbert T, Birbaumer N, Ray W J, Schupp H
Universität Tübingen, Germany.
Brain Topogr. 1992 Fall;5(1):27-34. doi: 10.1007/BF01129967.
The insights gained by the concept of deterministic chaos for the EEG is that this seemingly disordered process may be governed by relatively few simple laws which could be determined. One of the quantitative measures of a complex dynamical system is that of its dimension. The term 'dimension' refers to the ability of a space to contain a set of points. We estimated the correlational dimension of the EEG and compared the outcome to traditional Fourier analyses. In addition, we tested the hypothesis that the EEG can be described as filtered noise. Data from 15 electrode sites and 31 subjects are reported in the present study. We have utilized a variety of tasks that cut across sensory modalities including touch, vision, and imagery which reflect neuropsychological processes that differentially engage areas of the cortex in the first part of the study. In the second part, the differences between the perception of an object and the imagination of the same object were evaluated. The outcome shows variations between scalp sites for all measures and also variations between tasks in terms of dimensionality of the EEG. The hypothesis of a higher dimensionality ("complexity") of imagery compared to actual perceptual processing was confirmed. A statistical comparison between the maps generated by means of the various measures shows that different informations are extracted when using the different measures. There is also statistical evidence that the EEG cannot completely be described by the model of filtered noise.
确定性混沌概念为脑电图研究带来的深刻见解是，这个看似无序的过程可能由相对较少的简单定律所支配，而这些定律是可以确定的。复杂动力系统的定量度量之一是其维度。“维度”一词指的是空间容纳一组点的能力。我们估计了脑电图的关联维度，并将结果与传统傅里叶分析进行了比较。此外，我们检验了脑电图可被描述为滤波噪声的假设。本研究报告了来自15个电极位点和31名受试者的数据。在研究的第一部分，我们采用了多种跨越感觉模态的任务，包括触觉、视觉和意象，这些任务反映了不同程度地涉及皮层区域的神经心理过程。在第二部分，评估了对物体的感知与对同一物体的想象之间的差异。结果表明，所有测量指标在头皮位点之间存在差异，脑电图维度在不同任务之间也存在差异。与实际感知处理相比，意象具有更高维度（“复杂性”）的假设得到了证实。通过各种测量方法生成的图谱之间的统计比较表明，使用不同测量方法时会提取不同的信息。也有统计证据表明，脑电图不能完全用滤波噪声模型来描述。
