ECHO-PLANAR MAGNETIC-RESONANCE-IMAGING STUDIES OF FRONTAL-CORTEX ACTIVATION DURING WORD GENERATION IN HUMANS
ECHO-PLANAR MAGNETIC-RESONANCE-IMAGING STUDIES OF FRONTAL-CORTEX ACTIVATION DURING WORD GENERATION IN HUMANS
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DOI：
10.1073/pnas.90.11.4952
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发表时间：
1993-06-01
影响因子：
11.1
通讯作者：
SHULMAN, RG
中科院分区：
文献类型：
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作者：
MCCARTHY, G;BLAMIRE, AM;SHULMAN, RG
在执行基于语言的任务时，通过高速磁共振成像对九名受试者进行了研究。要求受试者重复或生成与实验者读出的名词相关的动词，同时获得左下额叶的磁共振图像。使用梯度回波时间为 70 ms 的回波平面成像序列，给出明显的横向弛豫时间加权（T2*，对局部血红蛋白水平敏感。图像每 3 秒（重复时间）采集一次，共 32 个。平面内分辨率为 6 x 4.5 毫米，切片厚度为 10 毫米。信号的增加伴随着任务的执行，动词生成的激活显着增加 比重复。激活效应发生在任务开始后 3 秒内，并且可以在单个受试者的单张图像中观察到。激活的主要焦点出现在沿外侧沟前沟的灰质中，包括前岛、布罗德曼区 47，并延伸至区域 10。在被动聆听、隐蔽生成或口腔运动控制任务中，很少或没有发现该区域的激活。还发现显着的激活 右额叶皮层中的同源区域，但不是距状皮层中的控制区域。这些结果与之前的研究一致，之前的研究使用 O-15 标记的水作为血流示踪剂进行正电子发射断层扫描成像。
Nine subjects were studied by high-speed magnetic resonance imaging while performing language-based tasks. Subjects were asked either to repeat or to generate verbs associated with nouns read by an experimenter while magnetic resonance images were obtained of the left inferior frontal lobe. The echo-planar imaging sequence was used with a gradient echo time of 70 ms to give an apparent transverse relaxation time weighting (T2* that is sensitive to local hemoglobin levels. Images were acquired every 3 s (repetition time) in series of 32. In plane resolution was 6 x 4.5 mm and slice thickness was 10 mm. An increase in signal accompanied performance of the tasks, with significantly more activation for verb generation than for repeating. The activation effect occurred within 3 s after task onset and could be observed in single images from individual subjects. The primary focus of activation appeared in gray matter along a sulcus anterior to the lateral sulcus that included the anterior insula, Brodmann's area 47, and extending to area 10. Little or no activation of this region was found for a passive listening, covert generation, or mouth-movement control tasks. Significant activation was also found for a homologous region in the right frontal cortex but not for control regions in calcarine cortex. These results are consistent with prior studies that have used positron emission tomography imaging with O-15-labeled water as a blood flow tracer.