Implicit and explicit sequence learning in DLD (Cler et al., 2024)

Purpose: Developmental language disorder (DLD) is a neurodevelopmental disorder that impacts approximately 7% of the population and is characterized by unexplained deficits in expressive and/or receptive components of language. A common procedural learning task, serial reaction time (SRT), has been used to develop models of the basis of DLD. However, paradigms involve differing levels of implicit and explicit learning during this task, muddying interpretations of the data. Here, we tested adults with DLD on implicit and explicit SRT tasks to better understand implicit and explicit procedural learning in this population. We hypothesized that adults with DLD would demonstrate reduced learning on only the implicit SRT task, as alternate explicit neural mechanisms could lead to equivalent performance on the explicit task.Method: Fifty participants (25 with DLD and 25 with typical language) completed implicit and explicit SRT tasks, measuring their ability to learn visually presented 10-element sequences. Group differences were evaluated on sequence learning, error rates, and explicit recall of the sequence after learning.Results: Sequence learning was the same between the groups on both tasks. However, individuals with DLD showed increased errors and significantly worse recall of the explicitly learned sequence.Conclusions: Results suggest that sequence learning may be intact in this population, while aspects of explicit learning and motoric responses are impaired. Results are interpreted in light of a neurobiological model of DLD.Supplemental Material S1. Group data.Supplemental Material S2. Group data: long version.Supplemental Material S3. R file for statistical analysis.Cler, G. J., Bartolo, S., Kim, J., Nolan, A., & Banel, S. (2024). Implicit and explicit sequence learning in adults with developmental language disorder. Journal of Speech, Language, and Hearing Research, 67(8), 2638–2652. https://doi.org/10.1044/2024_JSLHR-23-00551

目的：发育性语言障碍（DLD）是一种影响约7%人口的神经发育性疾病，其特征为语言表达和/或接受成分的未解释性缺陷。常见的程序性学习任务，序列反应时（SRT），已被用于构建DLD基础的模型。然而，在此任务中，涉及不同程度的隐性和显性学习，使得数据的解释变得模糊。在本研究中，我们对发育性语言障碍的成人进行了隐性和显性SRT任务的测试，以更好地理解该人群中的隐性和显性程序性学习。我们假设发育性语言障碍的成人仅在隐性SRT任务上表现出学习减少，因为替代的显性神经机制可能导致显性任务上的等效表现。方法：50名参与者（25名患有DLD，25名具有典型语言）完成了隐性和显性SRT任务，测量了他们学习视觉呈现的10元素序列的能力。对序列学习、错误率和学习后序列的显性回忆的组间差异进行了评估。结果：两组在两个任务上的序列学习相同。然而，DLD患者表现出更多的错误，对显性学习序列的回忆显著较差。结论：结果表明，该人群的序列学习可能完好无损，而显性学习和运动反应方面存在障碍。结果是在发育性语言障碍的神经生物学模型背景下进行解释的。补充材料S1：组数据。补充材料S2：组数据：长版本。补充材料S3：统计分析的R文件。Cler, G. J., Bartolo, S., Kim, J., Nolan, A., & Banel, S. (2024). 发育性语言障碍成人中的隐性和显性序列学习。言语、语言和听力研究杂志，67(8)，2638–2652. https://doi.org/10.1044/2024_JSLHR-23-00551