数字计算相关脑功能区定位的fMRI研究

目的 采用fMRI技术对数字计算相关的脑功能区进行定位，初步分析各脑功能区在数字计算中的作用。资料与方法 应用GE公司1．5T磁共振全身扫描仪对28名右利手志愿者进行TlWI和组块设计的数字默读、简单计算和复杂计算fMRI实验。采用SPM99软件进行数据分析和脑功能区定位。结果 数字默读实验脑激活区为左额下回后部、左角回、双侧额内回。简单计算和复杂计算均可见左侧前额皮层、双侧运动前区／中央前回、额下回后部、额内回、扣带回前部、颞下回后部、顶下小叶激活。右前额皮层激活仅见于复杂计算，复杂计算各脑区激活明显强于简单计算。结论 fMRI可对计算相关脑功能区进行定位。数字计算涉及多个脑功能区，各功能区可能在整体配合下完成任务，其中顶下小叶可能起核心作用。工作记忆在计算中也发挥重要作用。

Study of Localizing Brain Functional Areas Related to Digital Calculations with Functional Magnetic Resonance Imaging

Objective To localize functional areas related to digital calculations with fMRI and investigate the roles of these areas for digital calculations.Materials and Methods 28 right-handed healthy subjects received subvocal number reading, simple calculation and complex calculation experiment. Following block design, T 1WI and GRE-EPI fMRI were performed with a 1.5T whole body MRI scanner. SPM 99 was used to process data and localize functional areas.Results For subvocal number reading task, significant activations were observed in the left posterior part of inferior frontal gyrus, left angular gyrus, bilateral medial frontal gyrus. Dorsal lateral of left prefrontal cortex, bilateral premotor area, posterior part of inferior frontal gyrus, medial frontal gyrus, and cortex around intraparietal sulcus, posterior part of inferior temporal gyrus, were all activated during simple calculation and complex calculation task. Right dorsal lateral part of prefrontal cortex was activated only in the complex calculation. Compared with simple calculation, extent and magnitude of functional areas were increased obviously in complex calculation.Conclusion fMRI can readily detect brain function areas related to digital calculations. Multiple functional areas are related to digital calculations, and these areas may work together as a whole in processing arithmetic problems. Inferior parietal lobules may be the nerve center for calculation. Working memory also play an important role in digital calculation.