Princeton University.
Columbia University.
J Cogn Neurosci. 2018 Sep;30(9):1345-1365. doi: 10.1162/jocn_a_01308. Epub 2018 Jul 13.
The posterior medial network is at the apex of a temporal integration hierarchy in the brain, integrating information over many seconds of viewing intact, but not scrambled, movies. This has been interpreted as an effect of temporal structure. Such structure in movies depends on preexisting event schemas, but temporal structure can also arise de novo from learning. Here, we examined the relative role of schema-consistent temporal structure and arbitrary but consistent temporal structure on the human posterior medial network. We tested whether, with repeated viewing, the network becomes engaged by scrambled movies with temporal structure. Replicating prior studies, activity in posterior medial regions was immediately locked to stimulus structure upon exposure to intact, but not scrambled, movies. However, for temporally structured scrambled movies, functional coupling within the network increased across stimulus repetitions, rising to the level of intact movies. Thus, temporal structure is a key determinant of network dynamics and function in the posterior medial network.
大脑中的后内侧网络处于时间整合层次结构的顶端，它可以整合观看完整但未打乱的电影数秒的信息。这被解释为时间结构的影响。电影中的这种结构取决于预先存在的事件模式，但时间结构也可以通过学习从头产生。在这里，我们研究了模式一致的时间结构和任意但一致的时间结构对人类后内侧网络的相对作用。我们测试了随着重复观看，网络是否会被具有时间结构的打乱电影所激活。与之前的研究一致，在接触完整的（而非打乱的）电影时，后内侧区域的活动立即与刺激结构锁定。然而，对于具有时间结构的打乱电影，随着刺激重复，网络内的功能耦合增加，达到完整电影的水平。因此，时间结构是后内侧网络中网络动态和功能的关键决定因素。
