基于动态因果模型的视觉工作记忆任务脑效应网络研究

Study on Brain Effective Network during Visual Working Memory Task Based on Dynamic Causal Model

目的从多通道脑电(electroencephalographys,EEGs)的效应连接角度,探究工作记忆的脑网络机制。方法收集15名健康志愿者的32通道脑电数据,通过源定位确定视觉工作记忆任务的激活脑区,在此基础上进行动态因果模型(DCM)分析,计算各连接的超越概率,构建工作记忆脑效应网络。结果双侧顶叶(PAR)到同侧背外侧前额叶(DLPFC)和双侧顶叶(PAR)到同侧额中线皮层(MFC)连接的超越概率大于其它连接。模型中正向连接簇的超越概率EP_forward大于反向连接簇的超越概率EP_backward和横向连接簇的超越概率EP_lateral(P<0.01)。结论视觉工作记忆过程中,双侧顶叶与同侧背外侧前额叶、额中线皮层之间有信息交流,顶叶皮层的信息流向前额叶皮层。

0bjective To explore the brain network mechanism of visual working memory from the perspective of effectivity connectivity of multi-channel electroencephalogram （EEGs）. Methods 32-channel EEGs were recorded in 15 healthy subjects and the activated brain regions of visual working memory were determined by source localization. On this basis, the dynamic causal modeling （DCM） analysis was performed. The effective network of working memory was constructed by calculating the exceedance probability of each connection. Re- suits Compared to other connections, greater exceedance probability of connections from bilateral parietal cor- tex （PAR） to the ipsilateral dorsolateral prefrontal cortex （DLPFC） and from bilateral parietal cortex （PAR） to the ipsilateral middleline-frontal cortex （MFC） were observed. In the DCM, the exceedance probability of the forward family（EP_forward） was greater than that of the backward family （EP_backward） and the lateral family （EP_lateral, P 〈 0. 01 ）. Conclusion During visual working memory, information exchange of the bilat- eral parietal cortex with the ipsilateral dorsolateral prefrontal cortex and the middleline-frontal cortex existed, and the information inflowed from the parietal cortex to the prefrontal cortex.