摘要
静息态脑区的活动处于一种相对稳定的状态。但是,静息态机能性磁共振成像(functional Magnetic Resonance Imaging,fMRI)实验中,被试者可能会受到各种噪声的影响,因此,统计分析所得到的静息态脑区的活动强度和体素数都可能受此影响。为了更进一步研究静息态脑区的活动特点,分别对16名被试采集了8′14″的静息态fMRI数据,将这些数据按照时间等分为5个部分,对每个部分分别采用低频振幅方法进行分析。实验结果显示:楔前叶和后扣带皮层包含活动体素的个数随时间变化较小,处于一种相对稳定的状态;额内侧皮层和顶下小叶中活动体素个数随时间变化差异较大,处于不是很稳定的状态。实验结果表明,静息态脑区中,楔前叶和后扣带皮层对于外界噪声的干扰不敏感,额内侧皮层和顶下小叶对于外界噪声比较敏感。
Activity of resting-state brain regions is considered to be in a relatively stable state.However,resting-state functional magnetic resonance imaging（fMRI） experiments are probably affected by various noise,the activity intensity and the numbers of voxels in resting-state activity brain regions maybe affected.This study will investigate activation characteristics of the resting-state activity brain regions,to address the issue,16 subjects participate the functional MRI experiment,8 minutes and 14 seconds scan for each subject,then,the whole fMRI time serial were divided into 5 parts,each of which was analyzed by amplitude of low frequency fluctuation（ALFF） method.The results show that the numbers of activity voxels in precuneus and posterior cingulate cortex have slight changes over time,and the two brain regions are in a relatively stable state,whereas the number of activity voxels in medial frontal cortex and inferior parietal lobule are different over time,in a unstable state.The results suggest that medial frontal cortex and inferior parietal lobule are sensitive to noise,precuneus and posterior cingulate cortex are not.
