Department of Communication Sciences & Disorders, University of Wisconsin - Madison, Madison, WI, USA.
Department of Psychology, University of Wisconsin - Madison, Madison, WI, USA.
J Child Psychol Psychiatry. 2017 Nov;58(11):1251-1263. doi: 10.1111/jcpp.12734. Epub 2017 May 2.
Word learning is an important component of language development that influences child outcomes across multiple domains. Despite the importance of word knowledge, word-learning mechanisms are poorly understood in children with specific language impairment (SLI) and children with autism spectrum disorder (ASD). This study examined underlying mechanisms of word learning, specifically, statistical learning and fast-mapping, in school-aged children with typical and atypical development.
Statistical learning was assessed through a word segmentation task and fast-mapping was examined in an object-label association task. We also examined children's ability to map meaning onto newly segmented words in a third task that combined exposure to an artificial language and a fast-mapping task.
Children with SLI had poorer performance on the word segmentation and fast-mapping tasks relative to the typically developing and ASD groups, who did not differ from one another. However, when children with SLI were exposed to an artificial language with phonemes used in the subsequent fast-mapping task, they successfully learned more words than in the isolated fast-mapping task. There was some evidence that word segmentation abilities are associated with word learning in school-aged children with typical development and ASD, but not SLI. Follow-up analyses also examined performance in children with ASD who did and did not have a language impairment. Children with ASD with language impairment evidenced intact statistical learning abilities, but subtle weaknesses in fast-mapping abilities.
As the Procedural Deficit Hypothesis (PDH) predicts, children with SLI have impairments in statistical learning. However, children with SLI also have impairments in fast-mapping. Nonetheless, they are able to take advantage of additional phonological exposure to boost subsequent word-learning performance. In contrast to the PDH, children with ASD appear to have intact statistical learning, regardless of language status; however, fast-mapping abilities differ according to broader language skills.
词汇学习是语言发展的一个重要组成部分，它会影响儿童在多个领域的表现。尽管词汇知识很重要，但特定语言障碍（SLI）和自闭症谱系障碍（ASD）儿童的词汇学习机制仍未被很好地理解。本研究考察了具有典型和非典型发展的学龄儿童的词汇学习的潜在机制，特别是统计学习和快速映射。
通过词汇分割任务评估统计学习，通过对象-标签关联任务检查快速映射。我们还检查了儿童在将意义映射到新分割单词的第三个任务中的能力，该任务将对人工语言的暴露与快速映射任务相结合。
与典型发育和 ASD 组相比，SLI 儿童在词汇分割和快速映射任务中的表现较差，而 ASD 组彼此之间没有差异。然而，当 SLI 儿童接触到在随后的快速映射任务中使用的人工语言的音素时，他们在语言中的表现比在单独的快速映射任务中要好。有一些证据表明，词汇分割能力与典型发育和 ASD 儿童的词汇学习有关，但与 SLI 无关。后续分析还检查了具有和不具有语言障碍的 ASD 儿童的表现。具有语言障碍的 ASD 儿童表现出完整的统计学习能力，但在快速映射能力方面存在细微的弱点。
正如程序缺陷假说（PDH）所预测的那样，SLI 儿童在统计学习方面存在障碍。然而，SLI 儿童在快速映射方面也存在障碍。尽管如此，他们能够利用额外的语音暴露来提高后续的词汇学习表现。与 PDH 相反，无论语言状况如何，ASD 儿童似乎都具有完整的统计学习能力；然而，快速映射能力根据更广泛的语言技能而有所不同。
