Leber Andrew B, Turk-Browne Nicholas B, Chun Marvin M
Department of Psychology, University of New Hampshire, Durham, NH 03824, USA.
Proc Natl Acad Sci U S A. 2008 Sep 9;105(36):13592-7. doi: 10.1073/pnas.0805423105. Epub 2008 Aug 29.
Cognitive flexibility is a crucial human ability allowing efficient adaptation to changing task challenges. Although a person's degree of flexibility can vary from moment to moment, the conditions regulating such fluctuations are not well understood. Using a task-switching procedure with fMRI, we found several brain regions in which neural activity preceding each trial predicted subsequent cognitive flexibility. Specifically, as pretrial activity increased, performance improved on trials when the task switched but did not improve when the task repeated. Regions from which flexibility could be predicted reliably included the basal ganglia, anterior cingulate cortex, prefrontal cortex, and posterior parietal cortex. Although further analysis revealed similarities across the regions in how flexibility was predicted, results supported the existence of multiple independent sources of prediction. These results reveal distinct neural mechanisms underlying fluctuations in cognitive flexibility.
认知灵活性是一项至关重要的人类能力，它能让人高效地适应不断变化的任务挑战。尽管一个人的灵活性程度可能会随时刻而变化，但调节这种波动的条件却尚未得到充分理解。通过使用功能磁共振成像（fMRI）的任务切换程序，我们发现了几个脑区，其中每次试验前的神经活动可预测随后的认知灵活性。具体而言，随着试验前活动的增加，当任务切换时试验表现会提高，但任务重复时则不会提高。能够可靠预测灵活性的脑区包括基底神经节、前扣带回皮层、前额叶皮层和顶叶后皮层。尽管进一步分析揭示了这些脑区在预测灵活性方式上的相似性，但结果支持存在多个独立的预测源。这些结果揭示了认知灵活性波动背后不同的神经机制。
