Poster #49 - Number Morphosyntax and Numerical Comparison Abilities in Children with Down Syndrome

• In Event: 3-003 - Poster Session 09
  In Poster Session: PS 09 Section - Developmental Disabilities

Integrative Statement

The linguistic profile of children with Down syndrome (DS) is characterized by an expressive vocabulary deficit and morpheme omission (Caselli et al., 2000; Galeote et al., 2014; Lazaro et al., 2013; Vicari et al. 2000). However, little is known about whether there is an underlying impairment in their comprehension of morphological cues that might partially explain this expressive deficit. In the current study, we focused on one of the morphemes that typically developing Spanish speaking children learn first, the plural morpheme -s. Our goal was to evaluate the comprehension of number morphosyntactic cues of children with DS and their relationship with number comparison abilities.
To achieve our goal, we evaluated a group of 16 children with DS and a group of 16 typically developing (TP) children matched by receptive vocabulary (Mean verbal mental age DS = 41.81 months (SD = 12.37), Mean verbal mental age TP = 44.75 months (SD = 15.09)) with two preferential looking tasks. In the plural task, children had to map singular morphosyntactic cues (e.g., Mira, es una pona [“Look there is a pona”]) to images with one object or plural cues (e.g., Mira, son unas ponas [“Look there are some ponas”]) to images with two or four objects. In the number task, children were shown an image with 1 object and either an image with two or four objects and asked (e.g., ¿Dónde hay más? [“Where are there more?”]) to look at the image with more than one object.
Results showed that children with DS, along with their typically developing peers, were able to map plural morphosyntactic cues to collections of two or four objects (t(31) = 3.12, p = .004, Cohen’s d = 0.55), but failed to map singular cues to collections with only one object (t(31) = 1.50, p = .14). Unexpectedly, children from both groups failed to look at the image with more than one object in the number task (t(31) = 0.08, p = .935). Nevertheless, there was a medium strength negative correlation (r(30) = - 0.36, p = .04) between children’s comprehension in the singular trials and the time they spent looking at the image with only one object in the number task, suggesting that children who increased their looking times after hearing singular morphosyntactic cues were also those who had a preference to look at the image with only one big object when asked to look for ‘more’.
Overall, these results suggest that the comprehension of plural morphosyntactic cues in Spanish speaking children with DS is preserved. Previous studies with English speaking children with this syndrome have shown that they have lower plural comprehension scores than their peers matched by mental age (Joffe & Varlokosta, 2007). The lack of differences between children with DS and their typically developing peers in the current study may be related to the regularities in morphological information in Spanish. Furthermore, our results also suggest that the ongoing construction of singular cues’ meaning of children with DS might be linked to their numerical comparison abilities.

Authors

• Tania Jasso, Universidad Nacional Autónoma de México
  Presenting Author

• Roberto A Abreu-Mendoza, Universidad de Guadalajara
  Non-Presenting Author

• Elia E. Soto-Alba, Universidad Nacional Autónoma de México
  Non-Presenting Author

• Natalia Arias-Trejo, Universidad Nacional Autónoma de México, UNAM
  Non-Presenting Author