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【medical-news】计算障碍的根本原因
Public release date: 22-Mar-2007
The root of dyscalculia found
Scientists led by UCL (University College London) have induced dyscalculia in subjects without the maths learning difficulty for the first time. The study, which finds that the right parietal lobe is responsible for dyscalculia, potentially has implications for diagnosis and management through remedial teaching.
Dyscalculia is just as prevalent in the population as dyslexia and attention deficit hyperactivity disorder ?around 5% of the population is affected. However, dyscalculia has not been given the same attention as other disorders and the underlying brain dysfunction causing dyscalculia is still a mystery. It is hoped that this study will provide a better understanding of the condition and lead to better diagnosis and treatment.
Dr Roi Cohen Kadosh, of the UCL Institute of Cognitive Neuroscience, said: 揟his is the first causal demonstration that the parietal lobe is the key to understanding developmental dyscalculia. Most people process numbers very easily ?almost automatically ?but people with dyscalculia do not. We wanted to find out what would happen when the areas relevant to maths learning in the right parietal lobes were effectively knocked out for several hundred milliseconds. We found that stimulation to this brain region during a maths test radically impacted on the subjects?reaction time.
揟his provides strong evidence that dyscalculia is caused by malformations in the right parietal lobe and provides sold grounds for further study on the physical abnormalities present in dyscalculics?brains. It抯 an important step to the ultimate goal of early diagnosis through analysis of neural tissue, which in turn will lead to earlier treatments and more effective remedial teaching.?/p>
Using neuronavigated transcranial magnetic stimulation (TMS) to stimulate the brain, scientists were able to bring about dyscalculia in normal subjects for a short time while the subjects completed a maths task that involved comparing two digits, one larger in physical size than the other and the other larger numerically. For example, the subjects compared a 2 and a 4. The 2 was in a larger font than the 4 and subjects had to decide which digit was numerically larger.
The effect of TMS lasted only a few hundred milliseconds in the subjects and was brought on just at the point when the subject had to evaluate the numbers and decide which had the greater value or which was physically bigger. The test was designed to measure the subjects?automatic processing of numbers and was rolled out to both people with the dysfunction and those without it.
The researchers found that non-dyscalculic participants displayed dyscalculic-like behaviour in number processing only during TMS-induced neuronal activity disruptions to the right intraparietal sulcus. These findings were further validated by testing participants suffering from developmental dyscalculia. The results of the dyscalculic group reproduced the behavioural results obtained in non-dyscalculic volunteers during right parietal TMS, but not after left parietal TMS or sham stimulation.
This novel approach of directly comparing healthy participants with TMS-induced virtual dyscalculia to participants suffering from developmental dyscalculia enabled the researchers to propose a direct causal relationship between malfunctions along the right intraparietal sulcus and developmental dyscalculia. 本人已认领该文编译，48小时后若未提交译文，请其他战友自由认领。 The root of dyscalculia found
Scientists led by UCL (University College London) have induced dyscalculia in subjects without the maths learning difficulty for the first time. The study, which finds that the right parietal lobe is responsible for dyscalculia, potentially has implications for diagnosis and management through remedial teaching.
来自伦敦大学学院的科学家们首次使非数学学习困难的受试者产生计算障碍。他们的研究发现顶叶是计算障碍的功能区。这预示着治疗性教育有可能对该病的诊断和治疗有意义。 编译后：（893字）
计算障碍的根本原因
来自伦敦大学学院的科学家们首次使非数学学习困难的受试者产生计算障碍。他们的研究发现顶叶是计算障碍的功能区。这预示着治疗性教育有可能对该病的诊断和治疗有意义。
计算障碍在人群中的发病同诵读困难和注意力缺陷性多动症一样普遍，约5%的人受累。然而，与其他脑功能障碍相比，人们并未给与计算障碍更多的关注。至今引起计算障碍的根本原因仍是未解之谜。希望本研究对该病病因有更进一步的了解，以此提出更佳的诊断和治疗方法。
伦敦大学学院认知神经病学研究所的Roi Cohen Kadosh博士说：这是第一次证实，顶叶是理解力发展相关性计算障碍的关键部位。大部分正常人都可以轻松自如地处理数字。但有计算障碍的人就不行了。在几百毫秒的时间里，用有效的方法使受试者的右侧顶叶（该叶与数学学习相关）昏迷，将会发生什么，这是我们试图探究的。我们发现，对大脑此区的刺激从根本上影响受试者在数学测试中的反应时间。
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作者:admin@医学,生命科学 2011-09-08 17:12
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