Merriam E P, Colby C L, Thulborn K R, Luna B, Olson C R, Sweeney J A
Department of Neuroscience, University of Pittsburgh, Pittsburgh, Pennsylvania 15213, USA.
Neuroimage. 2001 May;13(5):794-800. doi: 10.1006/nimg.2000.0742.
We used functional magnetic resonance imaging (fMRI) to investigate cortical activation during the performance of three oculomotor tasks that impose increasing levels of cognitive demand. (1) In a visually guided saccade (VGS) task, subjects made saccades to flashed targets. (2) In a compatible task, subjects made leftward and rightward saccades in response to foveal presentation of the uppercase words "LEFT" or "RIGHT." (3) In a mixed task, subjects made rightward saccades in response to the lowercase word "left" and leftward saccades in response to the lowercase word "right" on incompatible trials (60%). The remaining 40% of trials required compatible responses to uppercase words. The VGS and compatible tasks, when compared to fixation, activated the three cortical eye fields: the supplementary eye field (SEF), the frontal eye field (FEF), and the parietal eye field (PEF). The mixed task, when compared to the compatible task, activated three additional cortical regions proximate to the three eye fields: (1) rostral to the SEF in medial frontal cortex; (2) rostral to the FEF in dorsolateral prefrontal cortex (DLPFC); (3) rostral and lateral to the PEF in posterior parietal cortex. These areas may contribute to the suppression of prepotent responses and in holding novel visuomotor associations in working memory.
我们使用功能磁共振成像（fMRI）来研究在执行三项认知需求不断增加的眼球运动任务过程中的皮质激活情况。（1）在视觉引导扫视（VGS）任务中，受试者对闪烁的目标进行扫视。（2）在一项匹配任务中，受试者根据中央凹呈现的大写单词“LEFT”或“RIGHT”进行向左或向右的扫视。（3）在一项混合任务中，在不匹配试验（60%）中，受试者根据小写单词“left”进行向右扫视，根据小写单词“right”进行向左扫视。其余40%的试验要求对大写单词做出匹配反应。与注视相比，VGS任务和匹配任务激活了三个皮质眼区：辅助眼区（SEF）、额叶眼区（FEF）和顶叶眼区（PEF）。与匹配任务相比，混合任务激活了靠近这三个眼区的另外三个皮质区域：（1）内侧额叶皮质中SEF前方的区域；（2）背外侧前额叶皮质（DLPFC）中FEF前方的区域；（3）顶叶后皮质中PEF前方和外侧的区域。这些区域可能有助于抑制优势反应，并在工作记忆中保持新的视觉运动关联。
