An Eye Movement Study On The Ability Of Autistic Children To Dissociate Visual Attention From Objects Of Restricted Interest

Attentional disengagement refers to the attentional breaking from current fixation during visual orienting.From the autistic studies,the actual evidence for it is still conflicting.A number of researchers concluded that attentional disengagement is impaired in children with autism spectrum disorder(ASD)and others reported no atypical.For ASD individuals,a prominent feature of nonsocial symptoms is circumscribed interest(CI).It is worth noting that,in most ASD studies,objects are often divided into two categories: CI-related materials and non CI-related ones.The CI-related parts also called high autism interest(HAI)objects(e.g.trains,planes,clocks etc.)and the non CI-related ones called low autism interest(LAI)objects(e.g.plants,clothes,furniture etc.).It remains unclear whether young aged autistic children exhibit sticky attention when facing different interesting types of objects.The current tasks used eye-tracking technology to examine the basic pattern of attentional disengagement and attentional processing of two types of cartoon objects.The disengagement hypothesis is that abnormal attentional disengagement is a prime suspect in the etiology of autism,and it could neatly explain many autistic symptoms.One of the goals of the present research is to explore whether this hypothesis could explain disengagement performance of young toddlers with ASD,in order to provide new directions for further autistic attentional research.The Experiment 1 aimed to test the basic attentional disengagement ability with simple shapes(circle and square)in ASD young children.The experimental design was 2(group: ASD vs.TD)×2(task: baseline vs.overlap)mixed design.15 ASD young children and 18 age,IQ matched TD contemporaries participated in the first study.The result implied that the basic attentional disengagement abilities developed normally in ASD preschoolers,which showed that there was no sign of impaired attentional disengagement problems in ASD young individuals.Their saccade reaction time is a little bit faster than typically developing(TD)peers' in the overlap tasks.The attentional disengagement effect and the disengaging failure rates were similar for both groups.This experiment showed that there was no evidence to proof abnormal attentional disengagement for basic figures in ASD toddlers.The second section consisted of two experiments,which was intended to explore the attentional preference and visual disengagement of CI stimuli in preschoolers with and without ASD.The Experiment 2.1 intended to investigate whether young children with ASD exhibited different visual behaviors when cartoon HAI and LAI materials appeared synchronously.We adopt 2(group: ASD vs.TD)×2(type: HAI vs.LAI)mixed design.22 ASD young children and 22 age,mental verbal IQ matched peers participated in this research.Results showed that autistic toddlers had abnormal visual preference for objects related to CI-related things.Compared to LAI objects,autistic young children manifested higher fixation ratio,more fixation counts and shorter fixation latency to HAI type.Nevertheless,for TD group,the preference for both types were close to chance level.The Experiment 2.2 aimed to investigate whether different interest types could influence attentional disengagement behaviors in young children with and without ASD by using the gap-overlap paradigm.2(group: ASD vs.TD)×2(task: baseline vs.overlap)×2(type: HAI vs.LAI)mixed experimental design was used to examine the attentional disengagement of 13 ASD preschoolers and 16 age,IQ matched TD counterparts.What we found was that,for both groups,their attentional disengagements were not influenced by two interest types.All participants had similar disengaging performances,and there was no sign of impaired disengagement in ASD group when CI-related objects appeared.From the current study,we came to the conclusions:(1)The basic ability of attentional disengagement for simple figures was intact in ASD toddlers.(2)ASD preschoolers had abnormal visual preference to CI-related cartoon materials.However,TD preschoolers didn't show any aberrant preference for both types.(3)The appearance of CI-related objects didn't have impact on children's disengagement performances.No matter what kind of interest types,both groups had similar saccadic reaction,and they can disengage from the current focus as fast as possible.(4)Young children with ASD exhibited lower attentional levels,which showed that their saccadic reactions are faster than their peer's.(5)Impaired disengaging hypothesis may not suitable for all young-aged ASD children.