Some Wh-Questions Really Are Hard for Children with ASD to Understand

Background:  Wh-questions are problematic for children with ASD. Prior research has shown delays in both production and comprehension of questions like “What did the apple hit?” and “Who pushed the doggy?”  in children with ASD compared to their typical peers (1, 2). However, earlier comprehension studies may have been limited because their stimuli included unfamiliar verbs (e.g., hit, produced by few children with ASD) and actions with inanimate agents and patients (e.g., an apple and a flower). The current study addressed both of these issues, testing wh-question comprehension with videos showing animate characters engaged in well-understood actions.  

Objectives: We investigate the degree to which including familiar verbs and animate characters will elicit robust comprehension of wh-questions by children with ASD.

Methods: Fourteen children with ASD (MA = 33.42 months) and 17 TD children (MA = 19.74 months) were assessed every four months for two years in this longitudinal study.  At visit 1, the children with ASD did not differ from the TD children in either Mullen Expressive (M_ASD=16.29, SD=6.64; M_TD=20.35, SD=5.70) or Receptive (M_ASD=19.64, SD=10.37; M_TD=22.76, SD=3.87) raw scores. At visits 1-2, children demonstrated understanding of SVO word order using intermodal preferential looking (IPL) videos in which a costumed horse and bird engaged in familiar actions (e.g., distinguishing ‘bird washes horse’ from ‘horse washes bird’ (3)).  At visits 3-6, children watched the Wh-Question video, in which each horse-and-bird action was followed by three types of trials in which the horse and bird appeared side by side. The audios were e.g., “Where is the bird/horse?” for Where/Control trials, “What washed the horse?” for Subject wh-questions and “What did the bird wash?” for Object wh-questions. Children’s eye movements were coded off-line. To show reliable comprehension, children should look longer at the named item (i.e., horse or bird) during the “where” questions than during the Subject-wh and Object-wh questions.

Results: Starting at 32 months of age, TD children looked significantly longer at the named item during the “where” trials than during both the object-wh and subject-wh-questions trials (ts(16) > 3.65, p< .002). The ASD group showed no significant differences between ‘where’ and subject-wh or object-wh questions even by Visit 6 (i.e., 53 months). Two (2 (group: ASD, TD) X 2 (trial: where vs. subject-wh or object-wh)) ANOVAs with the visit 4 data revealed a significant group x trial interaction for the ‘where’ vs. ‘subject-wh’ comparison (F(1,29) = 4.25, p= .048), indicating that the two groups showed different patterns of looking at this visit. Some children with ASD did show good wh-question comprehension at visit 3; these had higher Mullen Receptive and Expressive scores at visit 1. However, standardized test scores did not predict wh-question comprehension at later visits. 

Conclusions: Using highly familiar actions/verbs and animate characters as stimuli did not result in better wh-question comprehension by the children with ASD. In fact, they performed less consistently than their mental-age peers had in previous studies (2). We conclude that wh-questions present linguistic challenges to children with ASD that go beyond issues of stimuli.