Mechtenberg Hannah, Heffner Christopher C, Myers Emily B, Guediche Sara
Department of Psychological Sciences, University of Connecticut, Storrs, CT, USA.
Department of Communicative Sciences and Disorders, University at Buffalo, Buffalo, NY, USA.
Neurobiol Lang (Camb). 2024 Aug 15;5(3):757-773. doi: 10.1162/nol_a_00126. eCollection 2024.
Over the past few decades, research into the function of the cerebellum has expanded far beyond the motor domain. A growing number of studies are probing the role of specific cerebellar subregions, such as Crus I and Crus II, in higher-order cognitive functions including receptive language processing. In the current fMRI study, we show evidence for the cerebellum's sensitivity to variation in two well-studied psycholinguistic properties of words-lexical frequency and phonological neighborhood density-during passive, continuous listening of a podcast. To determine whether, and how, activity in the cerebellum correlates with these lexical properties, we modeled each word separately using an amplitude-modulated regressor, time-locked to the onset of each word. At the group level, significant effects of both lexical properties landed in expected cerebellar subregions: Crus I and Crus II. The BOLD signal correlated with variation in each lexical property, consistent with both language-specific and domain-general mechanisms. Activation patterns at the individual level also showed that effects of phonological neighborhood and lexical frequency landed in Crus I and Crus II as the most probable sites, though there was activation seen in other lobules (especially for frequency). Although the exact cerebellar mechanisms used during speech and language processing are not yet evident, these findings highlight the cerebellum's role in word-level processing during continuous listening.
在过去几十年里，对小脑功能的研究已远远超出运动领域。越来越多的研究正在探究特定小脑亚区域，如小脑 Crus I 和 Crus II，在包括接受性语言处理在内的高阶认知功能中的作用。在当前的功能磁共振成像（fMRI）研究中，我们展示了在被动持续收听播客期间，小脑对词汇的两个经过充分研究的心理语言学特性——词汇频率和语音邻域密度——的变化具有敏感性的证据。为了确定小脑的活动是否以及如何与这些词汇特性相关，我们使用一个调幅回归器对每个单词进行单独建模，该回归器与每个单词的起始时间同步。在群体水平上，这两个词汇特性的显著效应均出现在预期的小脑亚区域：Crus I 和 Crus II。血氧水平依赖（BOLD）信号与每个词汇特性的变化相关，这与特定语言机制和通用领域机制均相符。个体水平的激活模式也表明，语音邻域和词汇频率的效应最有可能出现在 Crus I 和 Crus II，但在其他小叶也有激活（尤其是频率方面）。尽管在言语和语言处理过程中所使用的确切小脑机制尚不明确，但这些发现凸显了小脑在持续收听期间单词层面处理中的作用。
