Iijima Mutsumi, Nishitani Nobuyuki
Department of Sensory & Communicative Disorders, Research Institute, National Rehabilitation Center for the Disabled, Tokorozawa, Japan.
Department of Neurology, Tokyo Women's Medical University School of Medicine, Tokyo, Japan.
Clin Neurophysiol Pract. 2016 Dec 27;2:54-61. doi: 10.1016/j.cnp.2016.10.003. eCollection 2017.
We elucidated active cortical areas and their time courses during simple calculation by using whole-scalp magnetoencephalography.
Twelve healthy volunteers were asked to view meaningless figures () or digits () and add single digits (). The magnetic signals of the brain were measured using a helmet-shaped 122-channel neuromagnetometer during the three tasks.
The occipital, inferior posterior temporal, and middle temporal areas of each hemisphere and the left superior temporal area (STA) were activated during all tasks (approximately 250 ms after the stimulus onset). The calculation-related sources were located in the left inferior parietal area (IPA) in 8 subjects, right IPA in 5, left STA in 3, right STA in 5, right inferior frontal area in 2, and left inferior frontal area in 1. The IPA and STA of the left hemisphere were activated more strongly and significantly earlier than those of the right hemisphere: the left IPA was activated first (mean activation timing: 301 ms), followed by activations of the left STA (369 ms), right IPA (419 ms), and right STA (483 ms).
Simple digit addition is executed mainly in the left IPA and left STA, followed by the recognition processes of results in the right IPA and right STA.
This study clarified the cortical process during simple calculation, with excellent temporal and spatial resolution; the IPA and STA of the left hemisphere were activated more strongly and earlier than the corresponding areas of the right hemisphere.
我们通过使用全头型脑磁图来阐明简单计算过程中活跃的皮质区域及其时间进程。
12名健康志愿者被要求查看无意义图形（）或数字（）并进行个位数相加（）。在这三项任务期间，使用头盔形状的122通道神经磁强计测量大脑的磁信号。
在所有任务期间（刺激开始后约250毫秒），每个半球的枕叶、颞叶后下部和颞叶中部区域以及左侧颞上区（STA）被激活。与计算相关的源位于8名受试者的左侧顶下区（IPA）、5名受试者的右侧IPA、3名受试者的左侧STA、5名受试者的右侧STA、2名受试者的右侧额下区和1名受试者的左侧额下区。左半球的IPA和STA比右半球的激活更强且明显更早：左侧IPA首先被激活（平均激活时间：301毫秒），随后是左侧STA（369毫秒）、右侧IPA（419毫秒）和右侧STA（483毫秒）被激活。
简单的数字加法主要在左侧IPA和左侧STA中执行，随后在右侧IPA和右侧STA中进行结果识别过程。
本研究以出色的时间和空间分辨率阐明了简单计算过程中的皮质活动；左半球的IPA和STA比右半球相应区域的激活更强且更早。
