不同状态下脑电图复杂性探索

COMPLEXITY OF EEG IN DIFFERENT FUNCTIONAL STATES

Ｌｅｍｐｅｌ－Ｚｉｖ所定义的有限序列的复杂性反映了给定序列随其长度的增长出现新模式的速率，事实上它反映了序列接近随机的程度。将该复杂性度量运用于脑电分析，旨在克服分数维方法的缺陷。文中计算了八种实验条件下脑电图的复杂度，涉及看、听、休息和心算等基本的大脑功能状态，１３个被试的１６导数据被用于计算分析．结果显示了复杂度在不同电极位置及实验条件下都有变化，睁眼状态的复杂度高于闭眼，而施加任务时有额部大脑活动区域复杂度降低的现象。同时复杂度也提供了一些研究大脑高级认知活动的新思路。

A measure of complexity defined by Lemple and Ziv (1976) represents the rate of new patterns generating in a given string when it's length grows,it is also a measure to describe a string in what degree to close to randomness. The reason why we apply this measure to EEG analyses is that it can oveimme some vital problna of the cochtion dion as a measure of the EEG.In this paper,we esthatal the complexity of the EEG under 8 differen experiInental conditions, induding seeing,hearing,taking act and doing arithmetic calCUtation, whichrepsome basic brain functional stabs.D&ta from 16 electrode sites and 13 male subjects are reported.The resultS show the complexity measure varies with scalp scalp sites and conditions.According to the statistics,the complexity meastire is higher When eye opened than closed,and lower when taking tasks than being free at the active scalp siams mainly localal in frontal area.It should also be stressed that the complexity measme wiht provide a new way to extlact borotant infonnation for cognhve process of human blain.