Key insights into why adults often struggle more than children to learn new languages.
前额叶皮层发育：成人的前额叶皮层（PFC）发育完全，这一区域在高级认知过程和执行功能中发挥着核心作用。虽然这些功能在许多情况下都是有益的，但它们可能会阻碍语言学习。相比之下，儿童的前额叶皮层尚未发育完全，这实际上有助于他们更轻松地习得新语言。这是因为语言学习在很大程度上依赖于非陈述性记忆，这种记忆方式比成人通常使用的陈述性记忆系统更为直观和不那么刻意。成人在学习新语言时经常依赖于前额叶皮层来记忆词汇和应用语法规则，这种方法对于语言习得来说可能不如儿童使用的无意识学习过程有效。
文献来源：https://bigthink.com/neuropsych/learning-new-language-adults/
Prefrontal Cortex Development: One major factor is the development of the prefrontal cortex (PFC). The PFC is fully developed in adults and plays a central role in higher-order cognitive processes and executive functions. While these functions are beneficial in many contexts, they can hinder language learning. Conversely, children have an underdeveloped PFC, which aids in acquiring new languages more effortlessly. This is because language learning heavily relies on non-declarative memory, which is more intuitive and less deliberate than the declarative memory system that adults typically use. Adults often rely on their PFC to memorize vocabulary and apply grammar rules, which can be less effective for language acquisition than children’s unconscious learning processes.
隐性与显性学习系统：儿童主要使用隐性（无意识）学习系统，通过被动暴露和体验来习得语言。然而，成人通常利用显性（有意识）记忆系统，重点放在有意识的学习机制上。这种方法可能会导致诸如使用母语翻译和尝试将熟悉的语言规则应用到新语言等问题，从而阻碍自然的语言学习过程。
Implicit vs. Explicit Learning Systems: Children primarily use an implicit (unconscious) learning system, acquiring language through passive exposure and experience. Adults, however, often utilize an explicit (conscious) memory system, focusing on conscious learning mechanisms. This approach can lead to issues such as translating from their first language and applying familiar linguistic rules to the new language, which can hinder the natural language learning process.
文献来源：https://bigthink.com/neuropsych/learning-new-language-adults/
神经科学视角：神经科学研究为成人如何学习新语言提供了洞见。成人可以通过统计学习等策略隐性地学习新语言，这种学习基于特定规则的发生概率，并且通常通过被动聆听发生。这种学习与记忆的编码、储存、巩固和检索过程密切相关。然而，与儿童相比，成人在语言学习过程中带入了预先存在的知识和经验。这既可以帮助也可以使学习新语言变得复杂。使用功能性近红外光谱（fNIRS）和脑电图（EEG）等神经科学方法研究了成人在语言学习过程中的这些过程，揭示了成人学习语言时各种大脑区域的复杂相互作用
Neuroscientific Perspectives: Neuroscientific research provides insights into how adults can learn new languages. Adults can learn implicitly through strategies like statistical learning, which is based on the probabilities of specific rules and often occurs through passive listening. This learning is intertwined with memory encoding, storing, consolidating, and retrieval processes. However, in contrast to children, adults have pre-existing knowledge and experience, which they bring to the language learning process. This can both aid and complicate the learning of new languages. Neuroscientific methods such as functional near-infrared spectroscopy (fNIRS) and electroencephalography (EEG) have been used to study these processes, revealing the complex interplay of various brain regions during language learning in adults.
文献来源：https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0246421
总之，成人在语言学习方面面临的挑战源于大脑发育的差异、使用的记忆系统类型以及成人带入学习过程中的预先知识。理解这些差异可以帮助我们为成人语言学习者找到更有效的策略。
In summary, the challenges adults face in language learning are rooted in the differences in brain development, the types of memory systems utilized, and the pre-existing knowledge that adults bring to the learning process. Understanding these differences can help develop more effective strategies for adult language learners.
