中文摘要：

利用功能磁共振成像（fMRI）进行脑功能研究是目前的一个热点，本文以逻辑计算为认知任务，利用fMRI进行数据采集，通过SPM软件分析得到激活脑区，提取感兴趣区（Regions of interest，ROD的平均BOLD信号（Average-BOLD），并利用主成分分析（Principal component analysis，PCA）方法提取ROI内BOLD信号（PCA—BOLD），通过Average-BOLD、PCA—BOLD信号与实验设计的逻辑任务曲线进行比较，认为PCA—BOLD信号可以更好的作为fMRI激活脑区的定量评估指标，用来衡量ROI激活强度，并进行脑功能基础研究。

英文摘要：

The study of brain function by fMRI is currently a cynosure of researchers. In this study, we performed mental calculation as a cognitive task and used MRI for data collection. Activated brain areas were found by the software of SPM. Moreover, the average of BOLD signal（Average-BOLD） and the principal component signal by principal component analysis（PCA） of BOLD signal（PCA-BOLD） in the regions of interest （ROD were figured. We compared these two sorts of signals versus the signal designed by the experiment. The results show that PCA-BOLD signal is a better parameter for quantitive evaluations of the activated brain areas and for the basic research of brain function by scaling the intensity of ROI.