一种基于fMRI激活实验数据分析的新方法

A new approach for analyzing activation experiment data based on fMRI

多种有关用统计学原理来分析fMRI数据这方面的方法已经被提出,并且得到了广泛的应用。这些分析方法的目的是为了产生一幅图像以用于确定任务相关的显著信号变化区。本文提出了一种控制—参考—频率法,该方法通过对时间序列的谱密度进行非参数估计来测试任务频率和血液动力学响应之间的关系,从而达到激活区定位的目的。之后本文通过分析同一组fMRI数据将这种方法和统计参数映射法和相关法进行了比较。实验结果证明了本文所提出的方法在探测由于运动任务所产生的激活区方面是有效的。该方法非常适合探测刺激任务是以周期序列的形式产生时的激活区。

Many strategies have been proposed for statistically analyzing functional magnetic resonance imaging (fMRI) data, and a variety of these are in general use. The aim of such analysis is to produce an image identifying the regions which show significant signal change in response to the task. A controlled-reference-frequency method is proposed in this paper, the proposed method involves testing for relations between the task frequencies and the hemodynamic response via non-parametric estimation of the spectral density of the time series to achieve location of the activated regions.After describing these strategies, the paper compared this method with Statistical Parametric Mapping (SPM)and correlation techniques by analyzing the same fMRI data sets. Experimental results demonstrate that the proposed method is effective for detecting activations resulting from a motor task.The proposed strategy is quite suitable for detecting active region when the stimulus task is presented in periodic sequence.