正常人工作记忆的事件相关fMRI研究

Study on Event-related fMRI of Working Memory in Healthy Subjects

目的:采用事件相关fMRI,探讨正常人工作记忆资源募集和干涉解决的神经基础。方法:采用Sternberg范例的一个亚型工作记忆选择任务,对正性和负性反应试验、低度熟悉负性试验和高度熟悉负性试验进行比较。结果:与正确正性反应相比,一些额叶区域,如扣带回前部(BA32)、额中回(双侧BA46、左侧BA9)、左侧额下回(BA44/45)以及右侧楔前叶(BA7)、右侧顶内沟前部(BA40)在做出正确负性反应时激活增加。与低度熟悉负性试验相比,高度熟悉负性试验中左侧额下回(BA44/45)、右侧楔前叶(BA7)、扣带前部(BA32)激活显著增加。结论:在工作记忆负性反应中需要募集更多的资源。额叶皮层和楔前叶可能是干涉解决的神经底物。

Objective：To study the basics of resource recruitment and interference resolution of working memory in healthy subjects using an event-related fMRI method. Methods：A subtype of Sternberg paradigm was used as memory selection task. Brain activations with positive and negative responses as well as in ＂low familiar negative＂ and ＂high-familiar negative＂ trials were compared. Results： In comparison to correct positive responses, increased activation in certain zones of frontal lobe,such as the anterior cingulate （BA32）, middle frontal （bilateral BA46, left BA9）, left inferior frontal gyri （BA44/45） ,and right precuneus （BAT） , right anterior intraparietal sulcus （BA40） was shown in case that correct negative responses were made. In contrast to ＂low familiar negative＂ trials, ＂marked increase of activation in left inferior frontal gyrus （BA44/45）,right precuneus （BAT）,and anterior cingulate （BA32） was indicated in case of ＂high familiar negative trials＂ responses. Conclusion：It was indicated that more brain resources should be recruited for processing correct negative responses. Frontal cortex and precuneus might be involving in processing interference resolution.