数字计算是人类生活中最为重要的认知功能之一。已有的研究认为顶叶是数字加工的主要功能区，其中顶下小叶及顶内沟负责数量加工，左侧角回负责算术事实的提取。然而对于数字加工单侧化优势问题，已有的研究结果存在矛盾。皮层电刺激技术是一项准确、可靠、安全的手术中功能监测技术，它能够暂时抑制相应皮层和皮层下组织的功能，从而实现精确的功能定位。本研究采用皮层电刺激技术以及一位数字减法任务，对8例脑胶质瘤患者（4例左侧肿瘤患者，4例右侧肿瘤患者）进行手术中数学功能监测。一方面，本研究探讨了顶叶数字加工单侧化优势这一学术问题，另一方面，手术中数学功能监测非常有助于保护脑肿瘤患者的计算能力，降低患者手术后出现计算障碍的风险。在手术开始前，我们对被试进行了手术前数学认知功能测验，包括简单反应时、一位数字减法、数字Stroop大小比较、数字言语工作记忆和标准型瑞文推理测验，所有被试的测验成绩均为正常值。在肿瘤切除手术过程中，我们应用皮层电刺激技术进行数学功能监测，实验任务包括图片命名任务和一位数字减法任务。在排除了语言干扰位点之后，我们从8名被试的脑部皮层中，共监测到19个计算干扰位点。它们集中分布在左侧顶叶的角回、顶内沟和缘上回。更为重要的是，19个计算干扰位点中16个位于左侧顶叶，3个位于右侧顶叶。研究结果表明左侧与右侧的计算干扰位点存在显著差异（P＝0.029），对于数字加工，大脑左侧顶叶比右侧顶叶更具优势，表现出顶叶数字加工左侧单侧化。据我所知，我们的实验是第一个运用皮层电刺激探讨数字加工单侧化的研究。在手术后，所有被试均未出现言语障碍，仅有1名被试出现了计算障碍，原因在于肿瘤切除中不可避免地损伤了计算干扰位点。其它7名被试，均未出现计算障碍。这一结果表明手术中的数学功能监测能够非常有效地帮助脑外科医生划定数字加工的重要功能区，在肿瘤切除时，以最大的可能性保留患者的计算能力，非常有必要在脑外科手术中应用。

Arithmetic is one of the most important cognitive function in human life. It is well established that the parietal lobe plays an important role in the processing of numerical magnitude. Neuropsychological and neuroimaging studies strongly suggest engagement of the intraparietal sulcus in processing of numerical magnitude and the left angular gyrus in the efficient retrieval of verbal mathematical facts from memory. However, the results of lateralization of numerical processing from previous studies are filled with inconsistencies. The cortical electrostimulation in awake surgery which can restrain cortical function temporarily is an easy, accurate, reliable, and safe technique of detection of cortical functionally essential structures. Eight glioma patients were recruited for the study (four left glioma patients and four right glioma patients). On the one hand, we discussed the academic issue of the lateralization of parietal numerical processing, and one the other hand, we tried to find an effective method to protect the arithmetical function of patients in brain surgery. Before the surgery, all the subjects had accomplished four mathematical cognitive tests to insure that they did not suffer from dyscalculia, including simple reaction test, single-digit subtraction, Stroop like numerical comparison and verbal working memory. In the surgery, patients were asked to perform both picture naming and single-digit subtraction task in electrostimulation mapping. We found 19 calculation-interference sites in the parietal lobe, excluding 20 language-interference sites. Moreover, of all the 19 calculation-interference sites, 16 calculation-interference sites were found in the left parietal lobe and located in the left intraparietal sulcus, left angular gyrus and supramarginal gyrus. The result suggested the left-lateralization of numerical processing. To my knowledge, this is the first time that lateralization of numerical processing was tested during cortical stimulation. After the surgery, none of patients suffered from dysphasia, and only one patient got dyscalculia within one month because of unavoidable injury of the calculation-interference sites during the tumor resection. We think the intraoperative calculation mapping is an effective method to avoid permanent postoperative deficit of arithmetic processes while optimising the quality of tumour resection. It is necessary to use single-digit subtraction task during electrostimulation mapping, especially when the operation in the dominant left parietal lobe.