Narayanan Nandakumar S, Prabhakaran Vivek, Bunge Silvia A, Christoff Kalina, Fine Eric M, Gabrieli John D E
Department of Psychology, Stanford University, Stanford, CA, USA.
Neuropsychology. 2005 Mar;19(2):223-32. doi: 10.1037/0894-4105.19.2.223.
Neuroimaging studies have been inconclusive in characterizing the role of the prefrontal cortex (PFC) for maintaining increasingly larger amounts of information in working memory (WM). To address this question, the authors collected event-related functional MRI data while participants performed an item-recognition task in which the number of to-be-remembered letters was parametrically modulated. During maintenance of information in WM, the dorsolateral and the ventrolateral PFC exhibited linearly increasing activation in response to increasing WM load. Prefrontal regions could not be distinguished from one another on the basis of load sensitivity, but the dorsolateral PFC had stronger functional connectivity with the parietal and motor cortex than the ventrolateral PFC. These results suggest an increasingly important role for the PFC in actively maintaining information as the amount of that information increases.
神经影像学研究在确定前额叶皮质（PFC）在工作记忆（WM）中维持越来越多信息的作用方面尚无定论。为了解决这个问题，作者收集了与事件相关的功能磁共振成像数据，同时参与者执行一项项目识别任务，其中要记住的字母数量被参数化调制。在工作记忆中信息维持期间，背外侧和腹外侧前额叶皮质对工作记忆负荷增加表现出线性增加的激活。前额叶区域在负荷敏感性方面无法相互区分，但背外侧前额叶皮质与顶叶和运动皮质的功能连接比腹外侧前额叶皮质更强。这些结果表明，随着信息数量的增加前额叶皮质在积极维持信息方面的作用越来越重要。
