Prediction and Early Language Development in Young Children with ASD

摘要 语言迟缓往往是患有自闭症谱系障碍(ASD)幼儿的父母最关心的问题之一， 早期的语言能力可以预测自闭症儿童的更广泛的结果。然而，机制 自闭症儿童潜在的语言缺陷仍未明确。语言学的一个重要组成部分 行为是在学习和处理过程中对预测或期望的使用。几位研究人员已经 最近提出了ASD的预测赤字账户。预测账户的基本假设是 信息是通过做出预测和测试违反预期(预测错误)来处理的。 灵活的(神经典型的)大脑将不同的权重归因于预测错误，以确定新的学习何时 适当的，而ASD患者被认为对预测错误给予了不成比例的权重。这些 假设预测缺陷会导致更高水平的感知新颖性，从而导致 根据最新的输入进行学习。这项拟议中的项目将是第一个研究语言是否 患有自闭症的幼儿的缺陷与非典型的一般领域预测过程有关。七项研究 建议解决以下具体目标：(1)确定患有自闭症的幼儿的生成能力 与典型发育中(TD)同龄人的预测比较；(2)确定患有自闭症的幼儿是否表现出 相对于TD同龄人的学习多塑性；(3)考察某些儿童特征在多大程度上 预测患有自闭症幼儿的预测行为和超塑性的个体变异性；以及(4)建立 语言/视觉任务的预测性行为或学习的多塑性是否能预测词汇量和/或 一年后自闭症儿童的句法能力。样本将由75名自闭症幼儿组成 (三组25名学步儿童)和75名TD对照--在认知(原始分数)、社会支持和性别方面匹配。 在这个项目中，我们将使用预期眼动(AEMS)和边听边看(LWL)方法来 研究患有和不患有自闭症的幼儿在视觉和言语任务中的预测能力。研究1(听觉)和研究2 (视觉)检查在以下情况下由AEMS编制索引的预测 事件相对稳定。研究3(语言)和研究4(非语言)将调查学习的超塑性 事件概率发生变化且预测必须更新的AEM任务。研究5将探索 使用LWL任务学习新词的情境中的多塑性。研究6将研究两者之间的关系 儿童特征(认知、语言、自闭症症状严重程度)和预测之间的关系。在研究7中， 研究1-5的表现将被用来预测同一样本幼儿的语言能力 之后(从18-35个月到30-47个月)使用标准化任务和在线增量语言处理 任务。所有研究都被开发为具有最低任务需求，以便将患有自闭症的蹒跚学步儿童纳入 广泛的功能。这项研究的发现将为ASD表型提供重要的新见解 以及语言发展的潜在机制，这可能会为干预开辟新的途径。

Abstract Language delay is often one of the first concerns of parents of toddlers with autism spectrum disorder (ASD), and early language abilities predict broader outcomes for children on the autism spectrum. Yet, mechanisms underlying language deficits in children with ASD remain unspecified. One prominent component of linguistic behavior is the use of predictions or expectations during learning and processing. Several researchers have recently posited prediction-deficit accounts of ASD. The basic assumption of the prediction accounts is that information is processed by making predictions and testing violations against expectations (prediction errors). Flexible (neurotypical) brains attribute differential weights to prediction errors to determine when new learning is appropriate, while individuals with ASD are thought to assign disproportionate weight to prediction errors. These prediction deficits are hypothesized to lead to higher levels of perceived novelty, resulting in `hyperplasticity' of learning based on the most recent input. The proposed project will be the first study to examine whether language deficits in young children with ASD are linked to atypical domain-general prediction processes. Seven studies are proposed to address the following Specific Aims: (1) to determine the ability of toddlers with ASD to generate predictions compared to typically developing (TD) peers; (2) to establish whether toddlers with ASD exhibit hyperplasticity of learning relative to TD peers; (3) to examine the extent to which certain child characteristics predict individual variability in predictive behavior and hyperplasticity in toddlers with ASD; and (4) establish whether predictive behavior or hyperplasticity of learning on verbal/visual tasks predicts vocabulary and/or syntactic ability one year later in young children with ASD. The sample will be comprised of 75 ASD toddlers (three cohorts of 25 toddlers) and 75 TD controls distribution-matched on cognition (raw scores), SES, and sex. In this project we will utilize anticipatory eye movements (AEMs) and looking-while-listening (LWL) methods to investigate prediction in visual and verbal tasks in toddlers with and without ASD. Studies 1 (auditory) and 2 (visual) examine prediction as indexed by AEMs under conditions in which probabilities of the occurrence of events are relatively stable. Studies 3 (verbal) and 4 (nonverbal) will investigate hyperplasticity of learning in AEM tasks in which probabilities of the events change and predictions must be updated. Study 5 will explore hyperplasticity within the context of novel word learning using a LWL task. Study 6 will examine the relationship between child characteristics (cognition, language, autism symptom severity) and prediction. In Study 7, performance on Studies 1-5 will be used to predict language abilities in the same sample of toddlers one year later (from 18-35 mo to 30-47 mo) using both standardized tasks and an online incremental language processing task. All studies were developed to have minimal task demands in order to include toddlers with ASD across a wide range of functioning. Findings from this research will provide important new insights into ASD phenotypes and mechanisms underlying language development that could open new pathways for intervention.