Department of Paediatric Neurosciences, Guy's and St Thomas' Foundation NHS Trust, London, UK.
Cortex. 2013 Feb;49(2):534-48. doi: 10.1016/j.cortex.2011.11.011. Epub 2011 Dec 7.
A study is reported of mathematical vocabulary and factual mathematical knowledge in PQ, a 22 year old with Down's syndrome (DS) who has a verbal mental age (MA) of 9 years 2 months and ST, a 15 year old with Williams syndrome (WS) who has a verbal MA of 9 years 6 months, matched to typically developing controls. The number of mathematical words contained within PQ's lexical stores was significantly reduced as reflected by performance on lexical decision. PQ was also impaired at both naming from descriptions and describing mathematical words. These results contrast with normal lexical decision and item descriptions for concrete words reported recently for PQ (Robinson and Temple, 2010). PQ's recall of mathematical facts was also impaired, whilst his recall of general knowledge facts was normal. This performance in DS indicates a deficit in both lexical representation and semantic knowledge for mathematical words and mathematical facts. In contrast, ST, the teenager with WS had good accuracy on lexical decision, naming and generating definitions for mathematical words. This contrasted with the atypical performance with concrete words recently reported for ST (Robinson and Temple, 2009). Knowledge of addition facts and general knowledge facts was also unimpaired for ST, though knowledge of multiplication facts was weak. Together the cases form a double dissociation and provide support for the distinct representation of mathematical and concrete items within the lexical-semantic system during development. The dissociations between mathematical and general factual knowledge also indicate that different types of factual knowledge may be selectively impaired during development. There is further support for a modular structure within which mathematical vocabulary and mathematical knowledge have distinct representations. This supports the case for the independent representation of factual and language-based knowledge within the semantic system during development.
一项针对 22 岁唐氏综合征（DS）患者 PQ 和 15 岁威廉姆斯综合征（WS）患者 ST 的数学词汇和事实性数学知识的研究报告，PQ 的言语心理年龄（MA）为 9 岁 2 个月，ST 的言语 MA 为 9 岁 6 个月，与正常对照组匹配。PQ 的词汇存储中包含的数学词汇数量明显减少，这反映在词汇判断测试中的表现上。PQ 在从描述中命名和描述数学词汇方面也存在障碍。这些结果与 PQ 最近报告的正常词汇判断和具体词汇描述形成对比（Robinson 和 Temple，2010）。PQ 对数学事实的回忆也受到损害，而他对一般知识事实的回忆则正常。DS 的这种表现表明，他的数学词汇和数学事实的词汇表示和语义知识都存在缺陷。相比之下，WS 患者 ST 在词汇判断、对数学词汇的命名和生成定义方面表现出色。这与最近报告的 ST 对具体词汇的非典型表现形成对比（Robinson 和 Temple，2009）。ST 对加法事实和一般知识事实的了解也未受影响，尽管对乘法事实的了解较弱。这两个病例形成了双重分离，为数学和具体项目在词汇语义系统中的发展提供了明确的代表。数学和一般事实知识之间的分离也表明，不同类型的事实知识可能在发展过程中选择性受损。这进一步支持了词汇语义系统中存在数学词汇和数学知识具有不同表示的模块化结构。这支持了在发展过程中语义系统中事实和基于语言的知识具有独立表示的观点。
