抑郁症患者情绪加工皮层间连接削弱:基于多变量自回归模型的相干分析

Cortico-Cortical Connectivity Decreased in Depression during Emotion Processing: Coherence Analysis by Multivariate Autoregressive Models

主要研究抑郁症和正常人在不同情绪认知任务下大脑功能性连接的差异。作者选取了12个抑郁症患者和12个正常被试进行正负情绪面孔搜索的认知任务,并同时记录头皮脑电。应用基于多变量自回归模型的相干分析方法计算了delta(1～3.5 Hz)、theta(4～7 Hz)、alpha(8～13 Hz)频带15个导联之间的连接,以及前额、顶枕区短距离连接和左右半球前额-顶枕区长距离连接。结果发现:1)刺激后1～200 ms,抑郁症患者在前额区delta、theta、alpha频带的短距离连接强度显著低于正常组,左前额-顶枕区delta、theta频带的长距离连接强度也明显低于正常组;2)正性情绪刺激下,正常人前额区delta、theta、alpha频带的短距离连接强度比负性情绪刺激下显著高,左前额-顶枕区delta、theta频带的长距离连接和右前额-顶枕区alpha频带的长距离连接强度比负性情绪刺激下也显著高。病人组情绪差异不明显。综上,前额区连接和左前额-顶枕区长距离连接的减小反映了病人在情绪认知任务下该神经网络功能性连接不充分,这可能揭示了抑郁症情绪加工障碍的机制。

This paper focused on the brain functional connectivity difference between the depression and the healthy during emotion processing. A visual search task about positive and negative face was performed in 12 depressed patients and 12 control subjects. As a measure of functional connectivity, EEG coherence based on MVAR modeling in delta, theta, alpha bands was calculated from 15 electrode sites. Further, the authors calculated anterior short-range connectivity, posterior short-range connectivity, left fronto-parietal and right fronto-parietal long-range connectivity. It was found that： 1） in depressed patients, the strength of anterior short-range connectivity for delta, theta and alpha bands were significantly smaller than the controls during 1-200 ms after stimulation onset, as well as the fronto-parietal long-range connectivity for delta and theta bands; 2） in normal group, the coherence value of anterior and posterior short-range connectivity for delta, theta and alpha bands were significantly larger for the positive stimulus than for the negative one. Similarly the left fronto-parietal long-range connectivity for delta and theta bands, and right fronto-padetal long-range connectivity for alpha band were larger for the positive stimulus. While for the depression, there was no emotional difference. These results indicated that the involvement of frontal and left fronto-pariertal network might be functionally insufficient in depressed patients which were reflected by decreased frontal and left fronto-pariertal coherence during emotion processing.