Zaunmüller Luisa, Domahs Frank, Dressel Katharina, Lonnemann Jan, Klein Elise, Ischebeck Anja, Willmes Klaus
Department of Neurology, University Hospital, RWTH Aachen University, Aachen, Germany.
Neuropsychol Rehabil. 2009 Jun;19(3):422-43. doi: 10.1080/09602010802296378. Epub 2008 Oct 1.
The present study investigates the effects of a training of arithmetic fact retrieval in a patient suffering from particular difficulties with multiplication facts. Over a period of four weeks simple multiplication facts were trained extensively. The outcome of the training was assessed behaviourally and changes in cerebral activation patterns were investigated using fMRI. The training led to a change in calculation strategies: Prior to training, the patient used predominantly time-consuming back-up strategies, after training he relied increasingly on the direct retrieval of arithmetic facts from long-term memory. Regarding the fMRI results, prefrontal activations were observed for untrained problems, which can be attributed to the application of back-up strategies strongly relying on fronto-executive functions. Interestingly, significant foci of activation for both trained and untrained items were found in the angular gyrus of the right hemisphere, which, however, differed in their exact localisation. For the trained condition, activations were observed in anterior parts of the angular gyrus which may be related to the training-based automatisation in fact retrieval. Activations in the untrained condition were found in a more posterior portion of the angular gyrus, that might be attributable to one of the patient's back-up strategies, namely to recite a whole multiplication row to get to the correct answer.
本研究调查了针对一位在乘法运算方面存在特殊困难的患者进行算术事实检索训练的效果。在四周的时间里，对简单乘法运算进行了广泛训练。通过行为学评估训练结果，并使用功能磁共振成像（fMRI）研究大脑激活模式的变化。训练导致了计算策略的改变：训练前，患者主要使用耗时的备用策略，训练后，他越来越依赖从长期记忆中直接检索算术事实。关于功能磁共振成像结果，在未经训练的问题中观察到前额叶激活，这可归因于强烈依赖额叶执行功能的备用策略的应用。有趣的是，在右半球角回中发现了训练项目和未训练项目的显著激活灶，然而，它们的确切定位有所不同。对于训练条件，在角回前部观察到激活，这可能与基于训练的事实检索自动化有关。在未训练条件下的激活出现在角回更靠后的部分，这可能归因于患者的一种备用策略，即背诵整个乘法行以得到正确答案。
