人脑对事件相关食物视觉刺激反应的功能磁共振成像的初步研究

目的通过功能磁共振成像(fMRI)初步研究人脑对事件相关食物视觉刺激反应.方法本研究利用fMRI技术具有时间分辨率高、对人体无创并且可以对单例数据处理分析的优势,采用平面回波成像(EPI)序列,检测在饥饿状态下,人脑对事件相关食物视觉刺激反应.实验中2名健康志愿受试者,选择事件相关任务模式禁食12 h后扫描.扫描的同时接受随机播放的食物图片、非食物图片和空白模糊图片的视觉刺激.用SPM 2软件处理功能成像数据,对由三类图片所引发的感兴趣区(ROI)做相关t检验统计.结果与食物渴求相关的脑区分布在杏仁核、眶额皮质以及枕叶皮质,与既往的正电子放射扫描成像(PET)实验结果相符.结论确定与食物渴求相关的奖赏通路,对于了解人类在饥饿状态下对食物渴求的复杂认知规律,为进一步寻找有效调控人类摄食行为的手段有重要意义.

The fMRI research on human brain responses to the event-related visual stimulation of food in fasting state

Objective To research the human brain responses to the event-related visual stimulation of food in fasting state with functional magnetic resonance imaging (fMRI). Methods A natural reward pathway which consists of some interconnected brain regions relates to the craving of food in the fasting state of human being. fMRI has high time resolution,low cost and less harm,the data acquired by fMRI can be processed and analyzed in single case. A pre-experiment was implemented with the echo planar imaging scan in the event-related design modality for two healthy volunteers. After fasting for 12 hours,the subjects accepted stimulations by the randomly presented pictures of food,non-food and blur objects during fMRI scanning. The functional data was processed with software statistical parameter mapping 2 (SPM2). After a t test to the region of interest (ROI) activated respectively by the three kinds of stimulation pictures. Results It found that the ROIs acquired were contained in the regions of amygdala,orbitofrontal cortex. These regions were much more corresponding to the ROIs acquired by positron emission tomography. Conclusion Confirming the reward pathway which related to visual stimulation of food is helpful for further finding the means of effectively controlling feeding action.