Magnetic brain activity evoked and induced by visually presented words and nonverbal stimuli
Magnetic brain activity evoked and induced by visually presented words and nonverbal stimuli
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DOI：
10.1111/1469-8986.3740447
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发表时间：
2000-07-01
期刊：
影响因子：
3.7
通讯作者：
Elbert, T
中科院分区：
文献类型：
--
作者：
Eulitz, C;Eulitz, H;Elbert, T
测试了在左半球测量的诱发和诱导磁脑活动对语言相关处理的特异性。诱发活动是指与刺激时间锁定但相位不锁定的振荡变化。焊接，假字体刺激，和两种类型的非语言模式的视觉呈现，而受试者进行非语言视觉特征检测任务。刺激开始后200 ms左右诱发和诱导的大脑活动的比较显示了对刺激的不同敏感性。与非言语刺激相比，诱发磁场的M180分量在处理单词和假字体刺激时更大。在60 Hz频段内，在一个兼容的潜伏期范围内，诱导的磁脑活动与视觉完形的熟悉度相关。如果一个参数区分条件和非词汇条件，则可以得出对特定语言信息加工的敏感性。在位于额颞头皮区域的感应器处观察到这种差异，用于感应而不是诱发磁脑活动。因此，诱发和诱导磁脑活动显示了不同的敏感性元素的认知处理在给定的任务。
Evoked and induced magnetic brain activity measured over the left hemisphere were tested for their specificity to language-related processing. Induced activity refers to oscillatory alterations time locked but not phase locked to the stimulus. Welds, false font stimuli, and two types of nonverbal patterns were presented visually while subjects performed a nonlinguistic visual feature detection task. The comparison of evoked and induced brain activity around 200 ms after stimulus onset revealed differential sensitivity to the stimuli. The M180 component of the evoked magnetic field was larger at the processing of words and false font stimuli compared with nonverbal stimuli. The induced magnetic brain activity in the 60-Hz band at a compatible latency range was col-related with the familiarity of the visual Gestalt. Sensitivity to language-specific information processing can be concluded if a parameter differentiates condition from the nonlexical conditions. Such a difference was observed at sensors located over the frontal-temporal scalp regions for induced but not evoked magnetic brain activity. Thus, evoked and induced magnetic brain activity revealed a differential sensitivity to elements of cognitive processing during the given task.