前运动皮质与数字加工:脑功能成像研究的元分析研究

Premotor Cortex and Numerical Processing: A Meta-analysis of Functional Neuroimaging Studies

许多应用PET与fMRI技术的脑功能成像研究发现,数字加工任务会显著引起前运动皮质的激活。习惯上认为,这一结果可能与任务执行过程中的动作反应,如手指按键、默读或眼动等有关。近年来的研究则表明,这一区域不仅具有动作功能,同时也具有其它非动作的认知功能。在本研究中,对17篇关于数字加工的脑功能成像研究进行了元分析,以考察前运动皮质在数字加工中的作用。研究结果发现,运动前区的背外侧(PMd)与腹外侧(PMv)在大多数数字加工任务中有显著激活,而运动辅助区(SMA)的激活则相对较少。数字比较、加法与减法任务在PMd区域有更多的激活,而乘法任务则在PMv区域有更多激活。数字自身特征对PMd、PMv与SMA喙部区域的激活有显著的调节作用。这一结果表明,前运动皮质在数字加工过程中可能扮演着比动作反应更为重要的角色。

A large body of PET and fMRI imaging studies has shown that the premotor cortex is significantly activated during numerical processing tasks. This was thought of as reflecting motor requirements during tasks, such as skeletomotor, aubvolcalization and occulomotor fagtors. However, Recent investigations have indicated both motor and non-motor functions of this region. Here we used the meta-analytic approach to explore the possible role of the premotor cortex in numerical processing. The results from 17 papers on numerical processing were re-analyzed. The dorsolateral （PMd） and ventrolateral premotor areas （PMv） were found to be significantly activated in most studies, while few involved SMA. Number comparison, addition and subtraction caused more activation in PMd, and multiplication caused more in PMv. The rostral parts of PMd, PMv and SMA were significantly modulated by numerical properties. This suggests a role of the premotor cortex not limited to motor reaction during numerical processing.