Activation of the prefrontal cortex in a nonspatial working memory task with functional MRI.
Activation of the prefrontal cortex in a nonspatial working memory task with functional MRI.
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DOI：
10.1002/hbm.460010407
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发表时间：
1994-01-01
影响因子：
4.8
通讯作者：
Noll, D C
中科院分区：
文献类型：
--
作者：
Cohen, J D;Forman, S D;Noll, D C
采用功能性磁共振成像（fMRI）技术研究了被试在非空间工作记忆任务中前额叶皮层的活动模式。受试者观察字母序列，并在字母重复时做出反应，其中插入了一个不相同的字母。在一项比较任务中，受试者监测类似的字母序列，以确定是否出现一个预先指定的目标字母。使用新开发的螺旋扫描图像采集技术进行功能扫描，该技术提供高分辨率，多切片扫描，其速度约为传统设备通常速度的五倍（平均每秒一张图像）。使用这些方法，在相对于比较任务执行工作记忆任务期间，在个体受试者中可靠地观察到额中回和额下回的激活。效应量（2-4%）与使用类似的fMRI技术在初级感觉和运动皮层中观察到的效应量非常接近。此外，激活增加和减少的时间过程是高度一致的任务操作。这些发现证实了正电子发射断层扫描研究的结果，正电子发射断层扫描研究表明，前额叶皮层参与了依赖于工作记忆的任务。此外，他们证明了新开发的功能磁共振成像技术的适用性，使用传统的扫描仪，研究在个别科目的联合皮层。© 1994 Wiley-Liss公司。
Functional magnetic resonance imaging (fMRI) was used to examine the pattern of activity of the prefrontal cortex during performance of subjects in a nonspatial working memory task. Subjects observed sequences of letters and responded whenever a letter repeated with exactly one nonidentical letter intervening. In a comparison task, subjects monitored similar sequences of letters for any occurrence of a single, prespecified target letter. Functional scanning was performed using a newly developed spiral scan image acquisition technique that provides high-resolution, multislice scanning at approximately five times the rate usually possible on conventional equipment (an average of one image per second). Using these methods, activation of the middle and inferior frontal gyri was reliably observed within individual subjects during performance of the working memory task relative to the comparison task. Effect sizes (2-4%) closely approximated those that have been observed within primary sensory and motor cortices using similar fMRI techniques. Furthermore, activation increased and decreased with a time course that was highly consistent with the task manipulations. These findings corroborate the results of positron emission tomography studies, which suggest that the prefrontal cortex is engaged by tasks that rely on working memory. Furthermore, they demonstrate the applicability of newly developed fMRI techniques using conventional scanners to study the associative cortex in individual subjects. © 1994 Wiley-Liss, Inc.