Pinheiro-Chagas Pedro, Chen Fengyixuan, Sabetfakhri Niki, Perry Claire, Parvizi Josef
Laboratory of Behavioral and Cognitive Neuroscience, Stanford Human Intracranial Cognitive Electrophysiology Program, Department of Neurology and Neurological Science, Stanford University, Stanford, CA, 94305, USA.
Brain Struct Funct. 2023 Jan;228(1):305-319. doi: 10.1007/s00429-022-02540-8. Epub 2022 Jul 30.
The role of angular gyrus (AG) in arithmetic processing remains a subject of debate. In the present study, we recorded from the AG, supramarginal gyrus (SMG), intraparietal sulcus (IPS), and superior parietal lobule (SPL) across 467 sites in 30 subjects performing addition or multiplication with digits or number words. We measured the power of high-frequency-broadband (HFB) signal, a surrogate marker for regional cortical engagement, and used single-subject anatomical boundaries to define the location of each recording site. Our recordings revealed the lowest proportion of sites with activation or deactivation within the AG compared to other subregions of the inferior parietal cortex during arithmetic processing. The few activated AG sites were mostly located at the border zones between AG and IPS, or AG and SMG. Additionally, we found that AG sites were more deactivated in trials with fast compared to slow response times. The increase or decrease of HFB within specific AG sites was the same when arithmetic trials were presented with number words versus digits and during multiplication as well as addition trials. Based on our findings, we conclude that the prior neuroimaging findings of so-called activations in the AG during arithmetic processing could have been due to group-based analyses that might have blurred the individual anatomical boundaries of AG or the subtractive nature of the neuroimaging methods in which lesser deactivations compared to the control condition have been interpreted as "activations". Our findings offer a new perspective with electrophysiological data about the engagement of AG during arithmetic processing.
角回（AG）在算术处理中的作用仍是一个有争议的话题。在本研究中，我们在30名进行数字或数字词加法或乘法运算的受试者的467个位点上，对角回、缘上回（SMG）、顶内沟（IPS）和顶上小叶（SPL）进行了记录。我们测量了高频宽带（HFB）信号的功率，这是区域皮质参与的替代标志物，并使用单受试者解剖边界来定义每个记录位点的位置。我们的记录显示，与顶下皮质的其他亚区域相比，在算术处理过程中，AG内激活或失活的位点比例最低。少数激活的AG位点大多位于AG与IPS或AG与SMG之间的边界区域。此外，我们发现，与反应时间较慢的试验相比，在反应时间较快的试验中AG位点的失活程度更高。当用数字词与数字呈现算术试验时，以及在乘法和加法试验期间，特定AG位点内HFB的增加或减少是相同的。基于我们的发现，我们得出结论，先前关于算术处理过程中AG所谓激活的神经影像学发现，可能是由于基于组的分析模糊了AG的个体解剖边界，或者是由于神经影像学方法的减法性质，其中与对照条件相比较小的失活被解释为“激活”。我们的发现为算术处理过程中AG的参与提供了有关电生理数据的新视角。
