听觉重复启动时默认模式网络变化的磁共振研究

Altered Functional Connectivity of the Default Mode Network in Auditory Repetition Priming:A Functional Magnetic Resonance Imaging Study

默认模式网络(default mode network,DMN)已逐渐成为脑功能成像研究中的热点。作者实验研究了10名被试在静息态、初次辨别声音和重复辨别声音(重复启动)三种情况下DMN功能连接的差异。结果表明,DMN功能连接的强弱顺序为:静息态>重复启动>初次辨别声音。相对于静息态下的DMN功能连接,重复启动时,内侧前额叶的连接显著减弱;初次辨别声音时,颞上回、舌回、顶下叶的连接显著减弱。初次辨别声音相对于重复启动,颞叶、后扣带、前扣带的连接减弱。这可能是因为三种情况下的任务负载依次越来越高,导致DMN功能连接强度越来越弱,即DMN功能连接的强度与任务的负载程度反相关。

Default mode network（DMN） has become a popular area in brain functional magnetic resonance imaging（fMRI） research.The authors investigated 10 subjects＇ DMN under three different conditions： resting state,identification the sounds for the first time,and identification the sounds under repeated priming.The results showed the order of the strength of DMN＇s functional connectivity is： resting state repetition priming first identification.Compared with resting state,the DMN＇s functional connectivity for the first identification had a significant decrease in the superior temporal gyrus,lingual gyrus,inferior parietal lobe.Compared with repetition priming,the DMN＇s functional connectivity for first identification had a significant decrease in the temporal lobe,posterior cingulate cortex,anterior cingulate.Such a decrease in the strength of DMN＇s functional connectivity might be resulted from the increase of the processing load of the three tasks.So the strength of DMN＇s functional connectivity might be negatively correlated with the processing load of the tasks.