A STUDY ON THE TEMPORAL CORRELATIONS OF THE FUNCTIONAL BRAIN AREAS USING FUNCTIONAL MRI

使用GE Horizon 1.5T临床磁共振成像机，进行功能磁共振成像(FMRI)实验。图像采集采用了两种方法，即全脑图像和选定的平面图像。统计参数映射(SPM)方法主要用于统计图像分析，在手指对位任务下激活主运动区和运动前区。两个区域之间存在相移，提示两个区域之间存在时间相关的相位延迟(相关)，在词汇生成任务中激活了Broca区和额叶联想区。另一方面，口吃受试者的经典语言区周围没有观察到激活。相反，观察到对侧前扣带回的激活。V2、V3、V5、IPS、STS和Broca区被基于双眼视差的随机点立体视觉显著激活，表明M通路主要参与其中。为了分析任务间干扰，发展了频率标记多任务(FLMT)方法。Broca区不干扰其他任务，但在单眼立体视觉时不会被激活，这表明该区域肯定参与了与双眼视差的距离评估。然而，我们没有观察到激活区域之间的任何相移，这表明立体视觉在人脑中处理得相当快。MTC-EPI方法已经成功地应用于手指对位任务。与仅使用BOLD效应的普通EPI相比，MTC-EPI对脑激活更敏感。另一方面，到目前为止，MTC-EPI对立体视觉的敏感性不是很高。MTC-EPI可能有利于局部激活。然而，要得出这一结论，还需要进一步调查。

Using a clinical MRI machine (GE Horizon 1.5 T), we conducted the functional magnetic resonance imaging (fMRI) experiments. Two kinds of methods were employed for the image acquisition, i.e. the whole brain image and the selected plane image. Statistical parametric mapping (SPM) method was mainly employed for the statistical image analysis.Primary motor area and pre-motor area were activated under the finger opposition tasks. Phase shift was observed between two regions, suggesting the time-dependent phase delay (correlation) between two regions.Broca's and frontal association area were activated during the word generation task. On the other hand, no activation was observed around the classical language area for the stuttering subjects. Instead, the activation of the anterior cingulate gyrus in the opposite side was observed. This is quite curious in light of the function of the anterior cingulate.V2, V3, V5, IPS, STS and Broca's area were significantly activated by the stereopsis of the random dot stereogram based on the binocular disparity, indicating that the M-pathway is mainly involved. Frequency labeled multiple task (FLMT) method has been developed in order to analyze the inter-task interference. Broca's area did not interfere with other tasks, but not activated during monocular stereopsis, suggesting that this region is definitely involved in the distance evaluation from the binocular disparity. However, we could not observe any phase shift between the activated areas, suggesting that the stereopsis is processed in the human brain quite rapidly.MTC-EPI method has been successfully applied to the finger opposition task. MTC-EPI was more sensitive to the brain activation compared to ordinary EPI using only the BOLD effect. On the other hand, MTC-EPI is not much sensitive for stereopsis so far. MTC-EPI may be advantageous for the localized activation. However, to conclude this, further investigation would be required.