How number processing survives left occipito-temporal damage
How number processing survives left occipito-temporal damage
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DOI：
10.1080/13554794.2011.588179
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发表时间：
2012-01-01
期刊：
影响因子：
0.8
通讯作者：
Price, C. J.
中科院分区：
文献类型：
--
作者：
Cappelletti, M.;Leff, A. P.;Price, C. J.
我们研究了一名左腹侧枕颞叶皮层（LvOT）受损的患者（JL）支持数字处理的神经系统。JL的书面文字识别能力严重受损，但他在数字任务中非常准确，尽管比正常人慢。这表明LvOT激活对于有效而不是准确的数字决策是必要的。在这里，我们调查了JL如何使用fMRI做出准确的数字决策;我们将JL的大脑激活与健康对照组和两名额叶损伤患者进行了比较，他们像JL一样，在数字任务中做出了缓慢但准确的反应。对于语义相对于知觉的决定，数字，JL没有激活左侧枕颞区，涉及在所有其他科目。然而，JL在左后中颞区的激活显著增加。此外，在对数字进行语义和感知决策时，JL在以下区域表现出更强的激活：（1）右侧枕颞叶皮层，（2）右侧尾状核，（3）双侧额叶区域。这些效应是JL独有的，不能用异常长的反应时间来解释，因为在其他做出缓慢但准确的数字决策的患者中没有观察到这些效应。总之，这些结果表明，虽然LvOT通常有助于有效的数字处理，激活在这个地区是不必要的准确性能，因为（i）知觉处理的数字可以支持右枕，右尾状核，和双边额叶激活和（ii）语义处理的数字可以支持增加左后中颞激活与手的动作。
We investigated the neural systems that support number processing in a patient (JL) who had damage to the left ventral occipito-temporal cortex (LvOT). JL had severely impaired written word recognition but he was remarkably accurate in number tasks, albeit slower than normal. This suggests LvOT activation is necessary for efficient but not for accurate number decisions. Here we investigated how JL made accurate number decisions using fMRI; we compared JL's brain activation to that in healthy controls and in two patients with frontal lobe damage who, like JL, made slow but accurate responses in number tasks. For semantic relative to perceptual decisions on numbers, JL did not activate the left occipito-temporal area that was involved in all other subjects. However, JL had significantly increased activation in a left posterior middle temporal region. In addition, during semantic and perceptual decisions on numbers, JL showed increased activation in: (1) the right occipito-temporal cortex, (2) right caudate, and (3) bilateral frontal regions. These effects were unique to JL and cannot be explained in terms of abnormally long response times because they were not observed in the other patients who made slow but accurate number decisions. Together these results show that although the LvOT usually contributes to efficient number processing, activation in this region is not essential for accurate performance because (i) perceptual processing of numbers can be supported by right occipital, right caudate, and bilateral frontal activation and (ii) semantic processing of numbers can be supported by increased left posterior middle temporal activation associated with hand actions.