Differences of early semantic relatedness between late talkers and typically developing children

Abstract

Objectives: Previous studies on late talkers (LT) suggested that residual linguistic deficits would remain in these children as they advance through the higher grades in school. This study investigated whether the residual linguistic deficits of LT exist from the infant and toddler stage by manifesting the differences of semantic relatedness between typically developing children (TD) and LT. Methods: Two hundred twenty-four reports of Korean MacArthur- Bates Communicative Development Inventories were used to investigate the semantic relatedness of infants and toddlers aged from 8 to 36 months. Semantic relatedness was measured by Jaccard's Index. After measuring the similarity of each group, one-way ANOVAs were conducted to investigate whether there were group differences. Three pairs of comparisons were made: infants' comprehension, toddlers' expression, and toddlers' comprehension. Infants' expression comparison was not conducted due to zero-expressive- words. Results: The differences between LT and TD infants were significant within the lexical categories in comprehension, except for 5 categories out of 18: 'Body parts,' 'Households,' 'Furniture and rooms,' 'Places,' and 'Quantifiers'. For toddlers, there was significant difference in every lexical semantic category both in expression and comprehension. All three pairs of comparison showed significant difference without categories. Conclusion: The current study results suggest that semantic relatedness is the key factor in word learning during infancy and that weak semantic relatedness in early age could lead to remaining linguistic residual deficits. Study results are discussed in regard to early intervention of 'at risk' children and suggest the direction of intervention for late talkers.