项目记忆和源记忆的功能磁共振成像研究

A fMRI study of item memory and source memory

目的探讨项目记忆和源记忆的神经基础及其是否存在性别差异。方法健康男女各8名,实验材料为504个高频双汉字词,项目记忆和源记忆实验任务,Block 设计,GE 1.5T 采集功能磁共振成像(fMRI)数据,用 SPM99分析,得到男女脑功能激活图(P<0.002,体素块>20)。结果在 P<0.002,体素块>20时,女性项目记忆激活双前额叶背外侧 BA6(激活数目左右侧分别为62和11个),源记忆较多激活左前额叶背外侧 BA6/46(激活数目为59个);男性项目记忆激活右前额叶背外侧 BA6/46(激活数目为64个),源记忆激活双前额叶背外侧 BA6(左右侧分别为9和40个)。结论项目记忆更多激活右侧前额叶背外侧,而源记忆更多激活左侧前额叶背外侧。女性较多地引起左前额叶背外侧激活;而男性较多地引起右前额叶背外侧激活。

Objective To examine the neural basis of item memory and source memory with fMRI approach. Methods Eight male and eight female healthy fight-handed native Chinese speakers were involved in this study. The item memory and source memory task were conducted with 504 highly frequent Chinese double-character words in the Block-designed experiment. Participants underwent such a doubleround procedure as fMRI scanning following study. The fMRI data collected from a GE 1.5T MRI system were analyzed to generate corresponding activation maps for females and males rspectively （ P 〈 0. 002, voxel clusters 〉 20 ） using statistical parametric mapping software （ SPM ）. Results For females, item memory task activated the bilateral dorsolateral prefrontal cortex（ BA6, the number of activated voxel clusters was 62 or 11 in the left and the fight, respectively ）, source memory more activated the left dorsolateral prefrontal cortex（ BA6/46, the number was 59 ）. For males, item memory activated the right dorsolateral prefrontal cortex（ BA6/46, the number was 64） , source memory activated the bilateral dorsolateral prefrontal cortex（BA6, 9 and 40 in the left and the fight）. Conclusion On the neural basis of item or source memory, there exists dissociation, which is that fight dorsolateral prefrontal areas are more activated by item memory while left dorsolateral prefrontal areas by source memory. For the difference of gender, it is suggested that left dorsolateral prefrontal areas （BA6/46） are more activated in females while fight dorsolateral prefrontal cortex （BA6/46） more in males.