知的障害のある児童における表出語彙—語連鎖段階および自閉スペクトラム症の有無との関連からの検討

Expressive vocabulary in children with intellectual disabilities:Examination from the relationship between the stages of word combination and the presence of autism spectrum disorder

　言語発達の初期に獲得される動詞や形容詞は，文の述部となり語連鎖の形成に寄与する重要な語彙カテゴリーである．本研究は1語文から3語以上の連鎖の文を表出する知的障害のある学齢児75名を対象とし，動詞・形容詞を中心とする表出語彙の質問紙調査から以下の3点を明らかにすることを目的とした：①語連鎖段階と表出語彙数との関連，②自閉スペクトラム症（ASD）の診断の有無による表出語彙の違い，③語の意味的特徴で体系化した知的障害児の中核的語彙．検討の結果，語連鎖の長さに伴い語彙数は有意に増加し，2語以上の連鎖を産出するASD児は非ASD児に比べて自発的に表出する形容詞の数が有意に少ないことが示された．調査対象の164語のうち32語は半数以上の児童が自発し，模倣による産出や学習場面のみでの表出も含めると110語がこのような中核的語彙に該当した．児の言語発達水準と意味的特徴に配慮した指導語彙の選択が重要であると考えられる．

　In early vocabulary development, verbs and adjectives, which constitute the predicates of sentences, are important in constructing word combinations. This study investigated the expressive vocabulary of 75 school-age children with intellectual disabilities who produced single-word sentences and sentences consisting of two or more words by using a questionnaire composed mainly of verbs and adjectives, and aimed at revealing the following:(1) relationships between the stages of word combination and the size of expressive vocabulary, (2) differences in vocabulary depending on the presence or absence of a diagnosis of autism spectrum disorder (ASD), and (3) the core vocabulary of children with intellectual disabilities with respect to the semantic characteristics of words. The results showed that vocabulary size increased significantly with increasing word combination length, and that children with ASD had a significantly smaller expressive vocabulary of adjectives than non-ASD children. Of the 164 words surveyed, 32 words were voluntarily produced by more than half of the children, while 110 words were produced by imitation and/or expressions in learning situations. The findings suggest the importance of selecting target words in consideration of the developmental level of the child's language and the semantic characteristics of words.