Chen Rui, Georgiou George K, Peng Peng, Li Yuanyuan, Li Beilei, Wang Jiali, Tao Sha
State Key Laboratory of Cognitive Neuroscience and Learning, Beijing Normal University, Beijing 100875, China.
IDG/McGovern Institute for Brain Research, Beijing Normal University, Beijing 100875, China.
Children (Basel). 2023 Oct 23;10(10):1719. doi: 10.3390/children10101719.
Both reading difficulties (RD) and mathematics difficulties (MD) are common neurodevelopmental disorders. The co-occurrence of RD and MD, known as comorbid RDMD, is estimated to range between 21% and 45% of children with learning disabilities. Deficits in working memory have been reported in both RD and MD groups, as well as among comorbid RDMD. However, previous comorbidity studies have only examined the role of some components of working memory, and they do not strictly match their groups on relevant reading and mathematics tasks. Thus, the purpose of this study is to examine the nature of working memory deficits in comorbid RDMD after matching groups based on reading and mathematics tasks. We assessed four groups of children (RD [ = 21, = 10.96 years], MD [ = 24, = 11.04 years], comorbid RDMD [ = 26, = 10.90 years], and chronological-age controls [ = 27, = 10.96 years]) on measures of the phonological loop (word span and digit span forward tasks), central executive (complex word and digit span), and updating tasks (word and digit 2-back). The results of ANCOVA (covarying for gender and non-verbal IQ) showed first that the RD and RDMD groups performed significantly worse than the MD and control groups in both measures of the phonological loop. For the central executive and updating tasks, we found an effect based on stimulus type. For word-related tasks, the RD and comorbid RDMD groups performed worse than the MD and control groups, and for number-related tasks, the MD and comorbid RDMD groups performed worse than the RD and control groups. Taken together, our findings provide support for the correlated liability model of comorbidity, which indicates that working memory deficits experienced by the RDMD group are an additive combination of deficits observed in the RD and MD groups, suggesting that working memory tasks used to examine underlying deficits in reading and/or mathematics difficulties may dictate whether or not significant group differences are found.
阅读障碍（RD）和数学障碍（MD）都是常见的神经发育障碍。RD和MD同时出现，即共病性阅读与数学障碍（RDMD），据估计在学习障碍儿童中占比21%至45%。在RD组和MD组以及共病性RDMD儿童中均报告存在工作记忆缺陷。然而，以往的共病研究仅考察了工作记忆某些成分的作用，并且在相关阅读和数学任务上并未严格匹配其分组。因此，本研究的目的是在根据阅读和数学任务匹配分组后，考察共病性RDMD中工作记忆缺陷的本质。我们评估了四组儿童（RD组[ = 21人，平均年龄 = 10.96岁]，MD组[ = 24人，平均年龄 = 11.04岁]，共病性RDMD组[ = 26人，平均年龄 = 10.90岁]，以及实足年龄对照组[ = 27人，平均年龄 = 10.96岁]）在语音回路（单词广度和数字广度顺背任务）、中央执行功能（复杂单词和数字广度）以及更新任务（单词和数字2-回溯）方面的表现。协方差分析（对性别和非言语智商进行协变量调整）结果首先表明，在语音回路的两项测量中，RD组和RDMD组的表现显著差于MD组和对照组。对于中央执行功能和更新任务，我们发现了基于刺激类型的效应。在与单词相关的任务中，RD组和共病性RDMD组的表现比MD组和对照组差；在与数字相关的任务中，MD组和共病性RDMD组的表现比RD组和对照组差。综合来看，我们的研究结果为共病的相关易感性模型提供了支持，该模型表明RDMD组经历的工作记忆缺陷是RD组和MD组中观察到的缺陷的累加组合，这表明用于检查阅读和/或数学障碍潜在缺陷的工作记忆任务可能决定是否能发现显著的组间差异。
