Encoding and consolidation of semantic meaning into the mental lexicon

项目摘要 本研究的总体目标是观察词汇学习的过程，并跟踪一个新单词的初始状态 学习并储存到语义记忆中。为了实现这一目标，该项目将记录电生理学 神经外科患者在进行语言学习任务时的活动。神经外科患者非常适合 参与这项研究是因为，出于临床原因，他们在头骨下植入了电极， 时间从1-3周不等。在此期间，这些电极将记录皮质电图（ECoG），而患者 参与学习任务，提供高时空分辨率的大脑活动一瞥，在正常的口头文字 学习功能。在这项研究中，任务是一个口头的单词学习任务，在该任务中，患者被呈现伪 没有意义的单词，并逐渐学会将特定的含义与每个单词联系起来。在文字呈现之后， 然后给患者四个选项，并要求其识别正确的语义。主要创新概念 我们将使用一个分类器来解码一个单词是已知的还是未知的，然后使用这个分类器 以确定在学习过程中未知单词变为已知的点。我们假设 词汇学习经历两个阶段：情景阶段和语义阶段。前者的特点是 海马激活，后者的特征在于外侧颞叶皮层中的网络连接增加。 如果成功的话，这一提议将不仅提供支持互补学习系统的实验证据 这是单词学习的一个重要观点，但它也代表了理解单词如何进入心理词典的第一步。 这些知识可能有助于重建心理词典，以应对心理词典发生病理性改变的情况，例如 失语症

Project Summary The overall goal of the proposed research is to observe the process of word learning, and track a new word as it is first learned and then stored into semantic memory. In order to accomplish that, the project will record electrophysiological activity from neurosurgical patients while they engage in a verbal learning task. Neurosurgical patients are well suited to participate in this study because, for clinical reasons, they have electrodes implanted beneath their skull for a period of time ranging from 1-3 weeks. During this time, these electrodes will record electrocorticography (ECoG) while patients engage in a learning task, offering a high spatiotemporal resolution glimpse into brain activity during normal verbal word learning functioning. In this study, the task is a verbal word learning task in which patients are presented with pseudo words with no meaning, and gradually learn to associate specific meaning to each word. After words are presented, the patient is then given four options and asked to identify the correct semantic meaning. The main innovative concept of this project is that we will use a classifier to decode whether a word is known or unknown, and then use that classifier to determine the point at which the unknown words become known during the learning process. We hypothesize that word learning goes through two stages: an episodic stage and a semantic stage. The former is characterized by hippocampal activation and the latter is characterized by increased network connectivity in the lateral temporal cortex. If successful, this proposal will not only provide experimental evidence supporting the complementary learning system view of word learning, but it would also represent a first step toward understanding how words enter the mental lexicon. This knowledge could potentially help rebuild the mental lexicon in cases where it is pathologically altered, such as aphasias.