PDF(Pubmed)
Abstract：
Functional magnetic resonance imaging (fMRI) studies have documented cerebellar activity across a wide array of tasks. However, the functional contribution of the cerebellum within these task domains remains unclear because cerebellar activity is often studied in isolation. This is problematic, as cerebellar fMRI activity may simply reflect the transmission of neocortical activity through fixed connections. Here, we present a new approach that addresses this problem. Rather than focus on task-dependent activity changes in the cerebellum alone, we ask if neocortical inputs to the cerebellum are gated in a task-dependent manner. We hypothesize that input is upregulated when the cerebellum functionally contributes to a task. We first validated this approach using a finger movement task, where the integrity of the cerebellum has been shown to be essential for the coordination of rapid alternating movements but not for force generation. While both neocortical and cerebellar activity increased with increasing speed and force, the speed-related changes in the cerebellum were larger than predicted by an optimized cortico-cerebellar connectivity model. We then applied the same approach in a cognitive domain, assessing how the cerebellum supports working memory. Enhanced gating was associated with the encoding of items in working memory, but not with the manipulation or retrieval of the items. Focusing on task-dependent gating of neocortical inputs to the cerebellum offers a promising approach for using fMRI to understand the specific contributions of the cerebellum to cognitive function.
摘要：
功能磁共振成像（fMRI）研究已经记录了一系列任务中的小脑活动。然而,小脑在这些任务域中的功能贡献尚不清楚，因为小脑活动通常是单独研究的。这是有问题的,因为小脑fMRI活动可能只是反映新皮层活动通过固定连接的传递。这里,我们提出了一种解决这个问题的新方法。而不是只关注小脑的任务相关活动变化，我们询问小脑的新皮质输入是否以任务相关的方式被门控。我们假设当小脑在功能上有助于任务时，输入被上调。我们首先使用手指移动任务验证了这种方法，小脑的完整性已被证明是必要的协调快速交替运动，但不是力量的产生。虽然新皮质和小脑活动都随着速度和力量的增加而增加，小脑的速度相关变化大于优化后的小脑-小脑连接模型预测的变化.然后我们在认知领域应用了相同的方法，评估小脑如何支持工作记忆。增强门控与工作记忆中项目的编码有关，但不能操作或检索项目。专注于小脑新皮层输入的任务依赖性门控为使用fMRI了解小脑对认知功能的具体贡献提供了一种有希望的方法。
