從磁振造影研究探討數學學習障礙之認知神經機制

THE COGNITIVE NEURAL MECHANISM OF MATHEMATICAL LEARNING DISABILITIES: INSIGHTS FROM MAGNETIC RESONANCE IMAGING STUDIES

數學能力不僅對學業與專業表現的成就來說相當重要，也是日常生活中，數量推理能力極為重要的一環。然而有一群人，包含學齡兒童、青少年甚至年輕人卻因其大腦結構與功能上的缺陷，而存在著根本的數學學習困難，這樣的困難被稱為數學學習障礙（mathematical learning disabilities, MLD）。MLD是一種智力與其他認知功能正常，只有在數學或數字方面有缺失的疾患。本文回顧當代腦造影研究中探討MLD神經機制之文獻，探討主題包含：（1）MLD者之認知與行為能力的缺損，包括相當初階之數量概念能力與基礎算術能力；（2）大腦中與數學能力相關之腦神經網絡，包括後頂葉、前額葉、內與外顳葉、及枕葉與顳葉交界，以及（3）MLD者的大腦在這些數學相關網路之結構與功能上出現的明顯缺陷；（4）在MLD族群進行的介入研究與補救教學，以及其對MLD者所產生之數學相關的表現改變與神經可塑性。本文末根據所回顧的文獻，提出幾個對於本土認知神經科學家以及教育者而言，仍待解決的重要議題。期待透過不斷進步的神經造影技術，我們將能翻開這個人類認知歷程中，數學是如何被學習的新篇章。

Mathematical cognition is a cognitive domain that is crucial not only for academic and professional success but also for quantitative reasoning in daily life. However, a wide range of individuals, including school-age children, adolescents, and even young adults, have difficulties in learning mathematics, which originates from their innate deficits in the structural and functional aspects of the brain. This type of difficulty, which is also known as mathematical learning disability (MLD), is a serious disorder with specific deficits in numerical and mathematical abilities, although intelligence and other cognitive skills remain intact. In this review, we discuss about contemporary studies that have used neuroimaging techniques to investigate the neural mechanisms of MLD, highlighting (1) the cognitive and behavioral impairments in numerical quantities and basic arithmetic problemsolving; (2) the neural circuits of numerical problem-solving encompassing the posterior parietal cortex, prefrontal cortex, anterior and lateral temporal lobes, and ventrotemporal occipital cortex; (3) the neurofunctional deficits of MLD anchored in the numerical problemsolving network; and (4) the interventional studies on MLD and the tutoring effect that induces behavioral and widespread neural plasticity. Finally, based on the current literature, we propose critical issues that remain unsolved for local cognitive neuroscientists and educators. Through the lens of the state-of-the-art neuroimaging techniques, the understanding of how individuals learn mathematics that is the hallmark of human cognition will be uncovered.