Curtis C E, Zald D H, Pardo J V
Cognitive Neuroimaging Unit, Veterans Affairs Medical Center, 1 Veterans Drive, Minneapolis, MN 55417, USA.
Neuropsychologia. 2000;38(11):1503-10. doi: 10.1016/s0028-3932(00)00062-2.
The prefrontal cortex plays a critical role in working memory, the active maintenance of information for brief periods of time for guiding future motor and cognitive processes. Two competing models have emerged to account for the growing human and non-human primate literature examining the functional neuroanatomy of working memory. One theory holds that the lateral frontal cortex plays a domain-specific role in working memory with the dorsolateral and ventrolateral cortical regions supporting working memory for spatial and non-spatial material, respectively. Alternatively, the lateral frontal cortex may play a process-specific role with the more dorsal regions becoming recruited whenever active manipulation or monitoring of information in working memory becomes necessary. Many working memory tasks do not allow for direct tests of these competing models. The present study used a novel self-ordered working memory task and positron emission tomography to identify whether dorsal or ventral lateral cortical areas are recruited during a working memory task that required extensive monitoring of non-spatial information held within working memory. We observed increased blood flow in the right dorsolateral, but not ventrolateral, prefrontal cortex. Increases in blood flow in the dorsolateral region correlated strongly with task performance. Thus, the results support the process-specific hypothesis.
前额叶皮质在工作记忆中起着关键作用，工作记忆是对信息进行短暂的主动维持，以指导未来的运动和认知过程。为了解释越来越多关于人类和非人类灵长类动物工作记忆功能神经解剖学的文献，出现了两种相互竞争的模型。一种理论认为，外侧额叶皮质在工作记忆中发挥特定领域的作用，背外侧和腹外侧皮质区域分别支持空间和非空间材料的工作记忆。另一种观点认为，外侧额叶皮质可能发挥特定过程的作用，每当需要对工作记忆中的信息进行主动操作或监控时，更多的背侧区域就会被激活。许多工作记忆任务无法对这些相互竞争的模型进行直接测试。本研究使用了一种新颖的自我排序工作记忆任务和正电子发射断层扫描技术，以确定在一项需要对工作记忆中保存的非空间信息进行广泛监控的工作记忆任务中，背侧或腹侧外侧皮质区域是否被激活。我们观察到右侧背外侧前额叶皮质血流量增加，而腹外侧前额叶皮质血流量未增加。背外侧区域血流量的增加与任务表现密切相关。因此，结果支持特定过程假说。
