Chapman R S, Seung H K, Schwartz S E, Kay-Raining Bird E
University of Wisconsin-Madison, USA.
J Speech Lang Hear Res. 1998 Aug;41(4):861-73. doi: 10.1044/jslhr.4104.861.
Hypotheses that children and adolescents with Down syndrome show (a) a specific expressive language impairment, (b) a "critical period" for language acquisition, (c) a "simple sentence syntactic ceiling" in production, and (d) deficit in grammatical morphology were investigated cross-sectionally. Conversational and narrative language samples from 47 children and adolescents with Down syndrome (Trisomy 21), aged 5 to 20 years, were compared to those from 47 control children aged 2 to 6 years matched statistically for nonverbal mental age. Children with Down syndrome appear to have a specific language impairment, compared to control children, in number of different words and total words (in the first 50 utterances) and in mean length of utterance (MLU). Total utterance attempts per minute were more frequent in the Down syndrome group. Narrative samples contained more word tokens, more word types, and longer MLU than conversation samples, for both groups. Intelligibility of narratives was significantly poorer for the Down syndrome group than controls. Analyses of narrative language sample by age sub-group showed no evidence of a critical period for language development ending at adolescence, nor of a "syntactic ceiling" at MLUs corresponding to simple sentences for the Down syndrome group. Omissions of word tokens and types were more frequent in the older Down syndrome than the younger control sample, matched on MLU.
唐氏综合征儿童和青少年表现出（a）特定的表达性语言障碍，（b）语言习得的“关键期”，（c）产出中的“简单句句法上限”，以及（d）语法形态缺陷。将47名年龄在5至20岁的唐氏综合征（21三体综合征）儿童和青少年的对话及叙事语言样本，与47名年龄在2至6岁、非言语心理年龄经统计学匹配的对照儿童的样本进行了比较。与对照儿童相比，唐氏综合征儿童在不同单词数量、总单词数（在前50个话语中）以及平均话语长度（MLU）方面似乎存在特定的语言障碍。唐氏综合征组每分钟的总话语尝试次数更为频繁。对于两组而言，叙事样本中的单词标记、单词类型更多，MLU也比对话样本更长。唐氏综合征组叙事的可理解性明显低于对照组。按年龄亚组对叙事语言样本进行分析，结果表明，没有证据显示语言发展的关键期在青春期结束，也没有证据表明唐氏综合征组在与简单句相对应的MLU存在“句法上限”。在按MLU匹配的情况下，年龄较大的唐氏综合征组样本中单词标记和类型的遗漏比年龄较小的对照样本更为频繁。
