Abstract:

Several previous studies consistently reported that children with Autistic Spectrum Disorder (ASD) had impairments in referential word learning when they are provided with only social eye gaze cues. More recent studies, however, suggested that children with ASD could use a speaker’s gaze direction to learn words when there were abundant additional perceptual cues enhancing the salience of the referent object. But their findings could not exclude the possibility that children in these studies just relied on perceptual cues to guide their word learning without noticing any social cues. In addition, it is also unknown that how ASD children in late childhood should respond when social cues conflict with perceptual cues. In order to examine the relative roles of social cues on word learning task compared to perceptual cues, the study recorded the eye movements of 18 verbally able children with ASD (M ages = 134.83 months) and their typical developing peers matched on receptive language and non-verbal intelligence (M ages = 71.61 months) while these two groups were completing word learning tasks under the following conditions: when gaze cues were no provided (No Gaze condition), when gaze cues were consistent with perceptual cues (Consistent Gaze condition), and when gaze cues were inconsistent with perceptual cues (Inconsistent Gaze condition). We found that, like typically developing (TD) children, children with ASD would map the novel word to the interesting object in the No Gaze condition and in the Consistent Gaze condition and the performance in the Consistent Gaze condition was better than that in the No Gaze condition. We also found that the ASD children would overlook perceptual cues to follow the speaker’s attention focus to pick up the boring object in the Inconsistent Gaze condition. Eye movement data results showed that: 1) the correct rate of first gaze following (the first saccades from face to target objects/ the first saccades from face to target and non-target objects) and the frequency of gaze following (saccades from face to target objects) in ASD children were lower than TD children; 2) the proportion of duration on eye region (fixation to eye region/ fixation to face region) in ASD children was higher than TD children; 3)there were no differences between two groups in the proportion of fixation to interesting object (fixation to interesting objects/ fixation to interesting and boring objects) and the proportion of gaze following (saccades from face to target objects/ saccades from face to target and non-target objects). The results illustrated that although social cues facilitated word learning in autism in overlapping cues condition and children with ASD also weighted social cues more heavily than perceptual cues, the style of capturing social cues in ASD children were different from TD children. They could not flexibly distribute attention resource according to the change in social scene, captured social information with the analytic way of feature process, and lacked the sensitivity of social information and the understanding of social meaning of social information.

Key words: autistic spectrum disorder, word learning, social cues, perceptual cues, eye-tracking