中文摘要：

目的工作记忆是一种在认知活动中对信息进行瞬时加工和贮存的记忆系统。笔者通过研究健康受试者在视觉工作记忆模式多通道脑电（multi—channel EEGs）的因果流（CV）分布模式，从信息传递特征角度为研究工作记忆机制提供支持。方法记录8例健康受试者共80次Sternberg视觉工作记忆实验中的16通道EEGs。对原始EEGs进行预处理后，应用快速傅里叶变换（FFT）分别计算每个通道EEG的能量，选取能量值最大的通道为特征通道，。对这个特征通道EEG进行时频分析，确定工作记忆特征频段。计算EEGs特征频段分量的定向传递函数（DTF）以及因果流。结果工作记忆EEG能量集中在FZ通道的0频段（4～8Hz）。EEG0频段因果流的特征模式：Fz通道因果流为最大的正值，C3、C4、C5、C6通道因果流为前4个绝对值最大的负值。结论0频段为工作记忆EEG的特征频段。额叶（Fz）是工作记忆信息流出的关键脑区（因果源），C3、C4、C5、C6为信息流人的主要脑区（因果汇）。

英文摘要：

Objective Ttle ability of working memory （WM） is to temporarily hold and manipulate information for cognitive tasks. The aim of this study was to investigate the causal flow distribution of multi-channel electroeneephalographs （EEGs） during Sternberg visual WM task to help understand WM mechanism from the view of neural information transform. Methods Sixteen-channel EEGs were recorded from 8 healthy subjects during Sternberg task, total EEG data for 80 trials were recorded and preprocessed. The EEG powers for each channel were calculated via Fast Fourier transform （FFT）. The feature channel was extracted based on the maximum power, and the feature frequency band for WM was determined by time-frequency analysis. The directed transfer function （DTF） and the value of causal flow in EEG feature frequency band were calculated. Results The EEG power focused on 0 band （4-8 Hz） and at Fz channel. The maximum value of causal flow was located at Fz, and the first 4 maximum negative values of causal flow were at C3, C4, C5, C6. Conclusions The feature frequency band for WM is the 0 band. The causal source （responsible region） is at Fz （frontal region） and the causal sinks are at C3, C4, C5, C6.