Connaughton Veronica M, Amiruddin Azhani, Clunies-Ross Karen L, French Noel, Fox Allison M
Neurocognitive Development Unit, School of Psychology, The University of Western Australia, 35 Stirling Highway, Crawley, WA 6009, Australia.
UWA Centre for Neonatal Research & Education, Perth, Australia.
J Neurosci Methods. 2017 May 1;283:33-41. doi: 10.1016/j.jneumeth.2017.03.010. Epub 2017 Mar 20.
A major model of the cerebral circuits that underpin arithmetic calculation is the triple-code model of numerical processing. This model proposes that the lateralization of mathematical operations is organized across three circuits: a left-hemispheric dominant verbal code; a bilateral magnitude representation of numbers and a bilateral Arabic number code.
This study simultaneously measured the blood flow of both middle cerebral arteries using functional transcranial Doppler ultrasonography to assess hemispheric specialization during the performance of both language and arithmetic tasks. The propositions of the triple-code model were assessed in a non-clinical adult group by measuring cerebral blood flow during the performance of multiplication and subtraction problems. Participants were 17 adults aged between 18-27 years. We obtained laterality indices for each type of mathematical operation and compared these in participants with left-hemispheric language dominance. It was hypothesized that blood flow would lateralize to the left hemisphere during the performance of multiplication operations, but would not lateralize during the performance of subtraction operations.
Hemispheric blood flow was significantly left lateralized during the multiplication task, but was not lateralized during the subtraction task.
COMPARISON WITH EXISTING METHOD(S): Compared to high spatial resolution neuroimaging techniques previously used to measure cerebral lateralization, functional transcranial Doppler ultrasonography is a cost-effective measure that provides a superior temporal representation of arithmetic cognition.
These results provide support for the triple-code model of arithmetic processing and offer complementary evidence that multiplication operations are processed differently in the adult brain compared to subtraction operations.
支持算术计算的大脑回路的一个主要模型是数字处理的三重编码模型。该模型提出，数学运算的脑区偏侧化是通过三个回路组织起来的：左半球占主导的语言编码；数字的双侧数量表征和双侧阿拉伯数字编码。
本研究使用功能性经颅多普勒超声同时测量双侧大脑中动脉的血流，以评估语言和算术任务执行过程中的半球特化情况。通过测量乘法和减法运算过程中的脑血流，在一个非临床成人组中评估三重编码模型的命题。参与者为17名年龄在18至27岁之间的成年人。我们获得了每种数学运算类型的偏侧化指数，并将这些指数在左半球语言占主导的参与者中进行比较。假设在乘法运算过程中血流会偏向左半球，但在减法运算过程中不会偏侧化。
在乘法任务期间，半球血流显著向左偏侧化，但在减法任务期间没有偏侧化。
与先前用于测量脑区偏侧化的高空间分辨率神经成像技术相比，功能性经颅多普勒超声是一种经济有效的测量方法，它能提供算术认知的更好的时间表征。
这些结果为算术处理的三重编码模型提供了支持，并提供了补充证据，表明在成人大脑中，乘法运算与减法运算的处理方式不同。
