University of North Carolina at Chapel Hill, NC, USA.
J Speech Lang Hear Res. 2012 Dec;55(6):1600-12. doi: 10.1044/1092-4388(2012/10-0153). Epub 2012 Apr 3.
To examine which cognitive, environmental, and speech-language variables predict expressive syntax in boys with fragile X syndrome (FXS), boys with Down syndrome (DS), and typically developing (TD) boys, and whether predictive relationships differed by group.
We obtained Index of Productive Syntax ( Scarborough, 1990) scores for 18 boys with FXS only, 20 boys with both FXS and an autism spectrum disorder, 27 boys with DS, and 25 younger TD boys of similar nonverbal mental age. Predictors included group (diagnosis), nonverbal cognition, phonological working memory (PWM), maternal education, speech intelligibility, and expressive vocabulary. The research questions were addressed via hierarchical linear regression.
Diagnostic group, nonverbal cognition, and PWM predicted 56% of the variance in syntactic ability, with approximately three-fourths of the predicted variance explained by group membership alone. The other factors did not contribute any additional significant variance in this final model. There was no evidence that predictor effects differed by group.
Nonverbal cognition and PWM have an effect on expressive syntax beyond that of diagnostic group. These effects are estimated to be the same in boys with FXS, boys with DS, and TD boys. Explanations for residual variance and the relative role of different predictors are discussed.
研究认知、环境和言语语言变量可预测脆性 X 综合征（FXS）男孩、唐氏综合征（DS）男孩和典型发育（TD）男孩的表达性语法，以及这些预测关系是否因组别而不同。
我们获得了仅 18 名 FXS 男孩、20 名同时患有 FXS 和自闭症谱系障碍的男孩、27 名 DS 男孩和 25 名具有相似非言语智力年龄的年轻 TD 男孩的生产性语法指数（Scarborough，1990）得分。预测因子包括组别（诊断）、非言语认知、语音工作记忆（PWM）、母亲教育程度、言语清晰度和表达性词汇量。通过分层线性回归来解决研究问题。
诊断组、非言语认知和 PWM 可预测语法能力的 56%，其中约四分之三的预测方差仅由组别的单一因素决定。其他因素在最终模型中没有增加任何显著的方差。没有证据表明预测因子的影响因组别而异。
非言语认知和 PWM 对表达性语法的影响超出了诊断组的影响。这些影响在 FXS 男孩、DS 男孩和 TD 男孩中估计是相同的。讨论了剩余方差的解释以及不同预测因子的相对作用。
