Abstract:
In 1974, Roger Sperry, based on his seminal studies on the split-brain condition, concluded that math was almost exclusively sustained by the language dominant left hemisphere. The right hemisphere could perform additions up to sums less than 20, the only exception to a complete left hemisphere dominance. Studies on lateralized focal lesions came to a similar conclusion, except for written complex calculation, where spatial abilities are needed to display digits in the right location according to the specific requirements of calculation procedures. Fifty years later, the contribution of new theoretical and instrumental tools lead to a much more complex picture, whereby, while left hemisphere dominance for math in the right-handed is confirmed for most functions, several math related tasks seem to be carried out in the right hemisphere. The developmental trajectory in the lateralization of math functions has also been clarified. This corpus of knowledge is reviewed here. The right hemisphere does not simply offer its support when calculation requires generic space processing, but its role can be very specific. For example, the right parietal lobe seems to store the operation-specific spatial layout required for complex arithmetical procedures and areas like the right insula are necessary in parsing complex numbers containing zero. Evidence is found for a complex orchestration between the two hemispheres even for simple tasks: each hemisphere has its specific role, concurring to the correct result. As for development, data point to right dominance for basic numerical processes. The picture that emerges at school age is a bilateral pattern with a significantly greater involvement of the right-hemisphere, particularly in non-symbolic tasks. The intraparietal sulcus shows a left hemisphere preponderance in response to symbolic stimuli at this age.
摘要:
1974年罗杰·斯佩里,根据他对裂脑状况的开创性研究,得出结论,数学几乎完全由语言主导的左半球维持。右半球可以进行总计小于20的加法,这是完全左半球优势的唯一例外。对局部病变的研究得出了类似的结论,除了书面的复杂计算,根据计算程序的具体要求,需要空间能力在正确的位置显示数字。五十年后,新的理论和工具工具的贡献导致了一幅更加复杂的图景,据此,虽然大多数功能都证实了左半球在数学中的优势,几个数学相关的任务似乎是在右半球进行。数学函数偏侧化的发展轨迹也得到了阐明。这里回顾了这个知识语料库。当计算需要通用空间处理时,右半球并不简单地提供其支持,但它的作用可能非常具体。例如,右顶叶似乎存储了复杂的算术程序所需的特定于操作的空间布局,并且在解析包含零的复数时需要像右脑岛这样的区域。即使是简单的任务,也有证据表明两个半球之间存在复杂的编排:每个半球都有其特定的作用,同意正确的结果。至于发展,数据指向基本数值过程的正确优势。在学龄期出现的图片是一种双边模式,右半球的参与程度明显更高,特别是在非象征性任务中。顶内沟在这个年龄段对象征性刺激的反应中表现出左半球优势。