Key Laboratory of Brain, Cognition and Education Sciences, Ministry of Education, Guangzhou, China.
School of Psychology, South China Normal University, Guangzhou, China.
Psychophysiology. 2021 Aug;58(8):e13834. doi: 10.1111/psyp.13834. Epub 2021 May 5.
Existing studies have identified crucial roles for the hippocampus and a distributed set of cortical regions (e.g., the inferior parietal cortex) in learning novel words. Nevertheless, researchers have not clearly determined how the hippocampus and cortical regions dynamically interact during novel word learning, especially during form-meaning associative learning. As a method to address this question, we used an online learning paradigm and representational similarity analysis to explore the contributions of the hippocampus and neocortex to form-meaning associative learning. Twenty-nine native Chinese college students were recruited to learn 30 form-meaning pairs, which were repeated 7 times during fMRI scan. Form-meaning associative learning elicited activations in a wide neural network including regions required for word processing (i.e., the bilateral inferior frontal gyrus and the occipitotemporal cortex), regions required for encoding (i.e., the bilateral parahippocampus and hippocampus), and regions required for cognitive control (i.e., the anterior cingulate cortex and dorsolateral prefrontal cortex). More importantly, our study revealed the differential roles of the left hippocampus and bilateral inferior parietal lobule (IPL) in form-meaning associative learning. Specifically, higher pattern similarity in the bilateral IPL in the early learning phase (repetitions 1 to 3) was related to better learning performance, while higher pattern similarity in the left hippocampus in the late learning phase (repetitions 5 to 7) was associated with better learning performance. These findings indicate that the hippocampus and cortical regions (e.g., the IPL) contribute to form-meaning learning in different stages.
已有研究确定了海马体和一组分布的皮质区域（例如，下顶叶皮质）在学习新单词中的关键作用。然而，研究人员尚未清楚确定海马体和皮质区域在新单词学习过程中（尤其是在形式-意义联想学习过程中）如何动态交互。作为解决此问题的一种方法，我们使用在线学习范式和表示相似性分析来探索海马体和新皮质对形式-意义联想学习的贡献。我们招募了 29 名母语为汉语的大学生，让他们学习 30 个形式-意义对，这些对在 fMRI 扫描过程中重复了 7 次。形式-意义联想学习在包括与单词处理相关的区域（即双侧额下回和枕颞叶皮质）、与编码相关的区域（即双侧海马旁回和海马体）以及与认知控制相关的区域（即前扣带皮层和背外侧前额叶皮层）在内的广泛神经网络中引发了激活。更重要的是，我们的研究揭示了左侧海马体和双侧下顶叶（IPL）在形式-意义联想学习中的差异作用。具体来说，在早期学习阶段（重复 1 到 3）双侧 IPL 中的更高模式相似性与更好的学习表现相关，而在晚期学习阶段（重复 5 到 7）左侧海马体中的更高模式相似性与更好的学习表现相关。这些发现表明海马体和皮质区域（例如 IPL）在不同阶段对形式-意义学习都有贡献。
