The main purpose of this study is to clarify the relationship between the manipulation of objects and play, and language in Down's syndrome children.
Fifteen Down's syndrome children from 9 months to 54 months old were observed playing with their mother using a set of toys including junk materials. These children were attending the infant intervention program at the University of Washington.
Manipulation of objects and play were analysed through the degree of symbolization, the decentration from the self and the combinatorial sequence.
Significant negative correlation between CA and the frequency of simple manipulation, and significant positive correlations between CA, and the frequency of total symbolic play, substitution play, sequenced play and relational manipulation were found.
Concerning language, the mean age of the expressive subdomain of the communication domain in Vineland Adaptive Behavior Scales significantly lower than mean age of the receptive subdomain.
Significant partial correlations controlling for CA were found between the expressive score of the communication domain in Vineland Adaptive Behavior Scales, the frequency of substitution play and the total frequency of symbolic play. Significant partial correlation controlling for CA were found between the receptive score and the frequency of supposition of symbolic play (pretend self-play). Significant positive correlation between maximum number of symbols included in sequenced play and maximum length of utterance was found. From the result of the correspondence of the number of symbols included in play and language, it was suggested that play and language develop in parallel until the stage of two-word utterances.