Comprehension of Head Nodding and Head Shaking Gestures in Early Childhood

Background:  

Impairments in responding to joint attention (RJA) bids are more useful for diagnosing Autism Spectrum Disorders (ASD) through childhood than they are later in development (Mundy, Sullivan, & Mastergeorge, 2009). However, RJA is typically tested only by examining responsiveness to gaze and point direction and to one’s name being called. Impairments processing more complex social cues may continue to differentiate typically developing children and those with autism later in development. By age four, typically developing children can use head nodding and head shaking gestures to identify correct label-object pairings (Fusaro & Harris, 2008). The current study examines receptivity to head nodding and head shaking gestures among preschoolers with ASD and typically developing controls, in a novel adjective-learning paradigm.

Objectives:  

This experiment examines preschoolers’ use of head gestures to learn adjective-object pairings. We test the prediction that preschoolers with ASD will show less systematic gesture comprehension than typically developing children.

Methods:  

To date, participants include 15 typically developing preschoolers (11 boys and 4 girls; M = 48.5 months; Range = 41-55 months) and 14 with ASD (10 boys and 4 girls; M = 49.1 months; Range = 42-55 months). Each child responded to eight trials presented via video on a Tobii eye tracking monitor. For each trial, an actress sat behind two pictures of an object, which differed in one salient characteristic (e.g., a book pictured in an upright and an inverted position). The actress stated “Look at these books. One of these is the [inverted book]. Let’s find the [inverted] one.” She then looked at each picture, indicated one by putting her hand on it, and either nodded or shook her head. Thus, the indicated object was the target in head nodding trials, and the non-target in headshake trials. The actress then prompted a response “Now you find the [inverted book], point to it.”

Results:  

Gesture scores equal the number of trials in which the child identified the correct target (max = 4 for head nods; max = 4 for head shakes). A Mixed ANOVA was calculated with group (ASD, Typical) as the between-subjects variable and gesture type (nod, shake) as the within-subjects variable. This analysis revealed a significant main effect of diagnostic group ((F, 1, 27) = 4.65, p = .04).  No other main effects or interactions were detected. Collapsing across gesture type, two-tailed t-tests confirmed that scores for typically developing children were above chance (2.0) level (M = 2.92, SD = .93; t = 3.80, p = .002), whereas scores among children with ASD did not differ significantly from chance (M = 2.25, SD = .71, t = 1.32, p > .10). 

Conclusions:  

As predicted, children with ASD are less systematic in their use of head nodding and head shaking gestures to make adjective-object pairings. Difficulties on this task may reflect diminished attention to the gesture or ineffective attention shifting between the gesturer and the targets. Ongoing eye-tracking analyses will allow us to test these hypotheses.