Anticipatory Gaze during Action Observation: Impact of Social Training on Children with ASD

Background:  

Anticipatory gaze in the context of goal directed hand actions are typically observed in children by their second year of life (Falck-Ytter, 2006; von Hofsten, 2004). Though, previous findings suggest that children with ASD tend to focus on mechanical properties of motion, with deficiency in social perception and attention to social activities (von Hofsten, 2009; Shic, 2011). With current intervention efforts to encourage social skills development (Kasari, 2012; Landa et al., 2011), it remains to be seen how goal-directed gaze is impacted by newly developed attentional biases (Chawarska, 2010). 

Objectives:  

Determine whether targeted social skills intervention improves social attention, without detriment to goal-directed attention and understanding of others’ object interaction.

Methods:  

Eighteen children with ASD participated in 5-months of parent-training (n=10), or ‘combined’-training (n=8) where parent-training was augmented with classroom training to promote social interaction with targets including (a) face-processing: attention to faces, face recognition; (b) social-anticipation: attention to human motion, action and intention understanding; and (c) imitation:  recognition of being imitated, imitation of others’ actions. Groups were similar on age, ADOS combined severity score, and Hollingshead (ps>.05, independent-samples-t-test).

We examined children’s anticipatory gaze while viewing a social agent (14-month-old toddler) moving a series of blocks across a table, with a cross-body motion, to a clear bowl. In trial1 (movement of first block), the actor looked at the bowl immediately upon touching the block. In trial2, a social gaze occurred where the actor first looked to the left – away from the target bowl. Children viewed this video-sequence in a dimly lit room, monitored by remote eye-tracker (Tobii X-120). Arrival of participants’ gaze to the bowl (target) in relation to arrival of the actor’s hand was measured in milliseconds, to assess their ability to anticipate the outcome of the actor’s action. Aggregate percentage of fixation times at the face and hand areas of interest (AOI) also were measured.

A three-way mixed ANOVA (Trial*Time*Group) assessed differences in anticipation times, with separate three-way mixed ANOVA (Time*Group*AOI) assessing differences in fixations to hand and face AOIs.

Results:  

Missing data (T1Pre=1; T2Pre=2; T1Post=3; T2Post=4) was replaced by multiple-imputation with 10-iterations. We found a significant Trial*Time*Condition interaction, across all imputations (mean p=.011±0.0097). The Time*Group*AOI interaction was also significant (p=0.022, η_p²=0.285).  

Conclusions:  

The Combined-training group progressed from a pre-intervention strong tendency to allocate attention to the moving hand in the scene to a post-intervention allocation of attention to socially relevant stimuli (the actor’s face). This, without losing awareness of the actor’s relocating of the blocks from the table to the bowl as indicated by preserved goal-directed anticipatory gaze. Thus, increased social interest does not impede the ability of children in the Combined-training group to attend to the task-relevant features in the dynamic scene (i.e., they still afforded attention to the bowl at the appropriate time to observe the block arrival). The Parent-training only group demonstrates decreased interest in the face AOI and increased attention to the hand from pre- to post-intervention, and increased degree of anticipatory gaze to the bowl from pre- to post-intervention.