Abstract Despite extensive behavioral research on complex word recognition, the neural mechanisms involved in the production of inflections in agglutinative languages, such as Finnish, are still poorly understood. Finnish inflected nouns typically involve morphophonological alternations of the stem (i.e. consonant gradation; CG), which is less common in other languages. Behavioral research on recognition of inflected nouns containing consonant gradation has shown that the number of stem allomorphs results in faster recognition times. To our knowledge, no functional magnetic resonance imaging (fMRI) studies have explicitly investigated consonant gradation in word production. In this study, participants performed covert and overt production tasks during event-related fMRI. Our stimuli comprised real word stems of high and medium frequency as well as pseudoword stems. The stems either included consonant gradation or were non-gradating. Our findings showed that the production of inflected forms containing high frequency stems or CG stems (irrespective of frequency and lexicality) yield enhanced activation of the left inferior frontal and middle frontal gyri (LIFG and MFG, respectively). This suggests that CG stems, that is, stems with more than one allomorph, facilitate lexical lookup, and that the activation of multiple stem allomorphs is reflected in increased recruitment of frontal brain regions.

中文翻译：

---

在公开和隐蔽生产过程中对芬兰语屈折形式的神经反应：词干频率和词干异形的作用

摘要 尽管对复杂单词识别进行了广泛的行为研究，但对芬兰语等粘着语言中产生屈折变化的神经机制仍知之甚少。芬兰语屈折名词通常涉及词干的形态音位变化（即辅音渐变；CG），这在其他语言中不太常见。对包含辅音渐变的屈折名词的识别行为研究表明，词干异形的数量会导致识别时间更快。据我们所知，没有功能性磁共振成像 (fMRI) 研究明确调查单词生成中的辅音等级。在这项研究中，参与者在事件相关的 fMRI 期间执行了隐蔽和公开的生产任务。我们的刺激包括高频和中频的真实词干以及伪词干。词干要么包括辅音渐变，要么是非渐变的。我们的研究结果表明，包含高频词干或 CG 词干（无论频率和词汇量）的屈折形式的产生增强了左额下回和额中回（分别为 LIFG 和 MFG）的激活。这表明 CG 词干，即具有多个同种异形体的词干，促进词汇查找，并且多个词干同种异形体的激活反映在额叶脑区的募集增加。我们的研究结果表明，包含高频词干或 CG 词干（不考虑频率和词汇量）的屈折形式的产生增强了左额下回和额中回（分别为 LIFG 和 MFG）的激活。这表明 CG 词干，即具有多个同种异形体的词干，促进词汇查找，并且多个词干同种异形体的激活反映在额叶脑区的募集增加。我们的研究结果表明，包含高频词干或 CG 词干（无论频率和词汇量）的屈折形式的产生增强了左额下回和额中回（分别为 LIFG 和 MFG）的激活。这表明 CG 词干，即具有多个同种异形体的词干，促进词汇查找，并且多个词干同种异形体的激活反映在额叶脑区的募集增加。