Department of Biomedical Engineering, Medical School, Tsinghua University, 1 Qinghuayuan, Haidian District, Beijing 100084, China.
Neurosci Lett. 2010 Mar 12;472(1):5-10. doi: 10.1016/j.neulet.2010.01.040. Epub 2010 Jan 25.
Functional neuroimaging data have shown that mental calculation involves fronto-parietal areas that are composed of different subsystems shared with other cognitive functions such as working memory and language. Event-related potential (ERP) analysis has also indicated sequential information changes during the calculation process. However, little is known about the dynamic properties of oscillatory networks in this process. In the present study, we applied both ERP and event-related (de-)synchronization (ERS/ERD) analyses to EEG data recorded from normal human subjects performing tasks for sequential visual/auditory mental addition. Results in the study indicate that the late positive components (LPCs) can be decomposed into two separate parts. The earlier element LPC1 (around 360ms) reflects the computing attribute and is more prominent in calculation tasks. The later element LPC2 (around 590ms) indicates an effect of number size and appears larger only in a more complex 2-digit addition task. The theta ERS and alpha ERD show modality-independent frontal and parietal differential patterns between the mental addition and control groups, and discrepancies are noted in the beta ERD between the 2-digit and 1-digit mental addition groups. The 2-digit addition (both visual and auditory) results in similar beta ERD patterns to the auditory control, which may indicate a reliance on auditory-related resources in mental arithmetic, especially with increasing task difficulty. These results coincide with the theory of simple calculation relying on the visuospatial process and complex calculation depending on the phonological process.
功能神经影像学数据表明，心算涉及由不同子系统组成的额顶区，这些子系统与其他认知功能（如工作记忆和语言）共享。事件相关电位（ERP）分析也表明了计算过程中顺序信息的变化。然而，对于这个过程中振荡网络的动态特性，我们知之甚少。在本研究中，我们应用 ERP 和事件相关（去）同步（ERS/ERD）分析来分析正常人类受试者执行视觉/听觉顺序心算任务时的 EEG 数据。研究结果表明，晚期正成分（LPCs）可以分解为两个独立的部分。早期元素 LPC1（约 360ms）反映了计算属性，在计算任务中更为突出。后期元素 LPC2（约 590ms）表示数字大小的影响，仅在更复杂的两位数加法任务中更为明显。theta ERS 和 alpha ERD 显示心算组和对照组之间的额顶区与模态无关的差异模式，而在两位数和一位数心算组之间的 beta ERD 中则存在差异。两位数加法（视觉和听觉）的 beta ERD 模式与听觉对照组相似，这可能表明心算依赖于听觉相关资源，尤其是在任务难度增加时。这些结果与简单计算依赖于视空间过程、复杂计算依赖于语音过程的理论相符。
