Early social communication deficits can identify in early year. It was developed well during infancy subsequently forms the base of successful language acquisition, academic performance and social adaptation so its normal development is important. Early social communicative symptoms overlap between Autism Spectrum Disorder (hereafter, ‘ASD’) and other developmental disorder/delay. Therefore, it can be difficult to differentiate between and
other delay in language development. Thus, this study attempted to look into the differences in early social communication ability between toddlers at risk for ASD and those with DLD or typical development. In addition, this study aims to find the variables, most effective for distinguishing a group at risk for ASD from a DLD group, among the early social communication variables.
A total of 75 toddlers aged between 16 and 35 months participated in this study. Based on each group M-CHAT, SELSI, K-BSID II or DEP wer used. They were matched according to chronological ages each other.
To collect behaviors sample of early social communication
behaviors, CSBS DP was used. The collected behaviors were measured for the total score, social, speech and symbolic composites and sub clusters and sub-items. For a statistical analysis of this study, a MANCOVA with the score on the mental developmental scale in the K-BSID as a covariate factors and a post-hoc analysis with the
Bonferroni procedure was carried out. In addition, to distinguish the at-risk for ASD from the DLD group, a direct discriminant function analysis was carried out with the sub-item of the CSBS DP, which had a significant difference in the MANCOVA, as an independent variable.
The results obtained through this research are as follows. First, there were significant differences among the three groups in the total score in the CSBS DP carried out to look into social communication ability. At-risk for ASD group showed an apperant deficit than those in toddlers with DLD as well as those in TD Toddlers in the DLD group showed a lower score than those in the TD group. There were significant differences in the scores of the social, speech, symbolic composite among the three groups. The at-risk for
ASD showed significantly lower performance in three domains as compared to the TD group while it showed significantly difference in the social and symbolic composites as compared to the DLD group. In contrast, the DLD group showed significantly lower performance only in
the speech domain as compared to the TD group. In terms of the score for each cluster, there were significant differences in the clusters of emotion and eye gaze, communication and gestures, consonants and use of words and those of language comprehension, object use and symbolic behavior among the three groups. At-risk for ASD showed significantly less than the TD group in all clusters of emotion and eye gaze, communication and gestures in the social domain and language comprehension in the symbolic composite In addition, as compared to the DLD group, it showed significantly lower performance in emotion and eye gaze, gestures, language comprehension, object use and symbolic behavior. In contrast, the DLD group showed significantly lower
performance only in production of consonants and use of words in the speech composite as compared to the TD group. Regarding the scores of sub-items by each cluster, there were significant differences among the three groups in shared positive affect, gaze following, rate of communication, conventional gesture, distal gesture, inventory of consonants, inventory of word combination,
language comprehension, action schemes toward others and sequences of action schemes. ASD group showed significantly lower performance in shared positive affect, rate of communication and distal gesture as compared to TD group while it showed significantly lower performance in
shared positive affect, gaze following, rate of mmunication,
conventional gesture and distal gesture as compared to DLD group. In the number of word combinations, both the ASD group and the DLD group showed significantly lower performance than the TD group. There were significant differences in the inventory of consonants, between the
DLD group and the TD group and between the DLD group and ASD groups. There were significant differences in language comprehension, action schemes toward others and sequences of action schemes between the ASD group and the TD group while there was a significant difference
only in language comprehension between the ASD group and the DLD group. There was no significant difference in the sub-items in the symbolic domain between the DLD group and the TD group. To find social communication variables that distinguish between ASD group and DLD group, a direct discriminant function analysis was
conducted. It was analyzed that it would be easy to discriminate groups when all sub-items in the CSBS DP, which had significant differences among the groups were put in. The clusters can be listed in the order of language comprehension, distal gesture, action schemes toward others according to their contribution to the classification of groups. Also, the hit ratio of all the groups was as high as 86%. This study attempted to distinguish the early social communication characteristics of toddlers under three at risk for ASD whose chronological age was matched, from the characteristics of those with DLD as well as TD toddlers. In particular, as a result of discriminant function analysis, planning an assessment and intervention focused on the factors useful for the classification of groups would be useful in terms of cost saving and curative value.