Two attentional processes in the parietal lobe
Two attentional processes in the parietal lobe
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DOI：
10.1093/cercor/12.11.1124
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发表时间：
2002-11-01
期刊：
影响因子：
3.7
通讯作者：
Corbetta, M
中科院分区：
文献类型：
--
作者：
Shulman, GL;d'Avossa, G;Corbetta, M
我们报告功能磁共振成像证据顶叶皮层的两个注意过程。受试者将一个由单词提示的特征与一个移动的彩色点的测试显示相匹配。在混合扫描上提示颜色（红色、绿色）或运动方向（左、右），而在分块扫描上仅提示一维。事件相关范式将线索产生的准备活动与测试显示相关的后续活动分开。一个注意过程指定的任务信息，而第二个过程是运动选择性。在提示期间，任务规范的纯效应在左额叶皮层观察到，而任务规范和运动选择性的组合效应在左后顶叶皮层观察到。额叶任务指定信号可能是顶叶皮层相应信号的来源。任务规范的效果概括了线索维度，表明信息编码在一个足够抽象的形式，影响颜色和运动处理。在随后的测试期间，任务指定和运动选择信号再次观察到左侧顶叶皮层。任务规范并没有显着影响枕叶运动选择性区域，如MT+，但是，这表明这个过程并没有影响运动处理流的皮层下层。这些结果为任务准备和执行过程中左顶叶皮层的一般和专门任务表征提供了证据。
We report fMRI evidence for two attentional processes in parietal cortex. Subjects matched a feature, cued by a word, to a test display of moving colored dots. Either color (red, green) or motion direction (left, right) was cued on mixed scans while only one dimension was cued on blocked scans. An event-related paradigm separated the preparatory activity generated by the cue from the subsequent activity related to the test display. One attentional process specified task information while a second process was motion selective. During the cue period, a pure effect of task specification was observed in left frontal cortex while combined effects of task specification and motion selectivity were observed in left posterior parietal cortex. The frontal task-specification signal may have been the source of the corresponding signal in parietal cortex. Effects of task specification generalized over cue dimension, indicating that the information was coded in a sufficiently abstract form to affect color and motion processing. During the subsequent test period, task-specification and motion-selective signals were again observed in left parietal cortex. Task specification did not significantly affect occipital motion-selective regions, such as MT+, however, indicating that this process did not influence the lower cortical tier of the motion processing stream. These results provide evidence for general and specialized task representations within left parietal cortex during task preparation and execution.