Fast Mapping In Word Learning By Children With Autism

Considerable researches about word learning in typical development children (referred to as TD) have amassed to show that with the increase of social interaction and the development of cognition, TD children can use various clues and strategies to learn words with a flexible way and experience a developmental process from a simple passive associationism mechanism to a complex initiative constructivism mechanism. In view of the specificity of vocabulary development in children with autism spectrum disorders (referred to as ASD), the researchers began to think about whether word learning in ASD children follow this learning process? What obstacles do they encounter in the completion of this transformation? What kind of differences are there in word acquisition mechanisms between ASD children and TD children? The dissertation will take verbally-able children with ASD as subjects to explore before-mentioned questions through a series of three studies:Study1investigated the ability of ASD children to learn words with social clues through a series of two experiments. Among them, Experiment1investigated the ability of ASD children to detect the referents of novel words with social attentional clues; Experiment2explored the ability of ASD children to do this with social intentional clues. The results showed that ASD children were able to take advantage of social attentional clues to detect the referents of novel words whether or not the intensity of social attentional cues were high or low, but they can not use indirect implicit social intentional clues to do this.Study2explored the ability of ASD children to learn words with non-social clues through a series of two experiments. Among them, Experiment3investigated the ability of ASD children to utilize perceptual cues and mutually exclusive principle to detect the referents of novel words。 Experiment4explored the ability of ASD children to make use of "shape bias" to extend the referents of novel words. The results showed that ASD children can take advantage of perceptual clues and mutually exclusive principles to detect the referents of novel words, but can not use "shape bias" to extend the referents of novel words. Study3investigated the ability of ASD children to learn words with multiple clues through a series of two experiments. Among them, Experiment5explored the ability of ASD children to do this on the case of attentional clues and mutually exclusive principle; Experiment6investigated the ability of ASD children to detect the referents of novel words on the condition of attentional and perceptional cues. The results show that the ability of ASD children to learn words significantly improve on consistent condition, while ASD children ignored perception cues and gave up mutual exclusion principle to follow attentional clues on conflict condition.Eye movement data results showed that:1) the frequency of gaze following (the times of 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 were higher than TD children;3) there were no differences between two groups in the proportion of fixation to the target objects (fixation to target objects/fixation to target and non-target objects) and the proportion of gaze following (saccades from face to target objects/saccades from face to target and non-target objects). The results indicated that the same gaze-following behavior may involve different underlying mechanisms:the gaze-following in ASD children may be volitional and inductive behaviors, while the gaze-following in TD may be reflexive and spontaneous behaviors. The volitional and inductive gaze-following suggested children with ASD could not flexibly distribute attention resource according to changes in social scene. They captured social information with the analytic way of feature process and lacked the understanding of social meaning.Making a general survey of three studies, word acquisition mechanism is different between TD children and ASD children. ASD children learn words in a highly limited way. Unlike TD children, they can not make use of various clues, skills or strategies to learn words flexibly and can not complete the transformation from a simple passive associationism mechanism to a complex initiative constructivism mechanism successfully. In consequence, they have a semi-constructivism word acquisition mechanism.