A Study On Eye Movement And Developmental Level In Toddlers At High Risk For Autism Spectrum Disorder

Objective: Toddlers at high risk for autism spectrum disorder(ASD),namely,toddler siblings of children with ASD,have a relatively increased risk for ASD and some characteristics of ASD,such as language delay,even if they do not develop ASD later.Previous studies have found that children with ASD have deficits in social attention,mainly manifested as preference for non-social stimuli.Similar findings have been found in HR-ASD toddlers.Therefore,this study used eye tracking and stimuli paradigms commonly used in previous studies to:(1)explore the gaze pattern of HR-ASD toddlers on social scenes;(2)explore whether HR-ASD toddlers have visual preference for non-social by simultaneously presenting social stimuli and non-social stimuli that toddlers with ASD may be interested in;(3)explore the ability of the abnormal gaze behaviors in HR-ASD toddlers to distinguish the risk of ASD.In addition,this study also examined the developmental level of HR-ASD toddlers.Methods: This study used a cross-sectional design and included HR-ASD toddlers(n=33),ASD toddlers(n=33)and typically developing(TD)toddlers(n=33).The gaze behaviors of all the subjects were recorded using eye tracker as they viewed scenes which included: 1)scenes of children’s interaction;2)people and cartoon dolls or 3)people and rotating objects.The toddlers’ developmental behaviors were assessed using Gesell Developmental Schedules,and developmental quotients(DQs)of adaptive behavior,gross motor,fine motor,language and personal social behaviors were analyzed.Covariance analysis was used to compare the differences of eye movement data and DQs among the three groups.Partial correlation analysis was used to explore the relationships between eye movement and developmental behaviors,and receiver operating characteristic(ROC)curve was used to explore the ability of eye movement indicators with differences among the three groups to distinguish the risk or diagnostic outcome of ASD.SPSS 25.0statistical software was used for statistical analyses.Results:(1)The DQs of adaptive behavior,gross motor,fine motor,language and personal social behaviors in HR-ASD group and TD group were significantly higher than those in ASD group(p<0.05),but there were no significant differences between HR-ASD group and TD group(p>0.05).(2)Social scenes: The first fixation duration and percentage of fixation time of action area of interest(AOI)in HR-ASD group were significantly higher than those in TD group(p<0.05),the percentage of fixation time of action AOI in ASD group was significantly higher than that in TD group(p=0.002),but there were no significant differences between HR-ASD group and ASD group(p>0.05).(3)People and cartoon dolls: Compared to TD group,HR-ASD group and ASD group were faster to fixate on the cartoon AOI(p<0.05),the first fixation duration of people AOI and percentage of fixation time of cartoon AOI in HR-ASD group and ASD group were significantly higher(p<0.05).Additionally,the first fixation duration of head and cartoon AOIs in HRASD group were significantly higher than those in TD group.There were no significant differences between HR-ASD group and ASD group(p>0.05).(4)People and rotating objects: The percentage of fixation time of object AOI in ASD group was significantly higher than that in TD group(p=0.002).There were no significant differences between HR-ASD group and TD group(p>0.05),and there were also no significant differences between HR-ASD group and ASD group(p>0.05)(5)There were no significant correlations between gaze data with group differences and ABC or M-CHAT scores in HR-ASD group or ASD group(p>0.05).(6)The percentage of fixation time of cartoon AOI used to distinguish HR-ASD group from TD group had the highest area under the ROC curve(0.81),and the corresponding sensitivity,specificity,positive predictive value and negative predictive value were 0.80,0.72,0.74 and 0.78,respectively.To distinguish ASD group from TD group,the percentage of fixation time of object AOI had the highest area under the ROC curve(0.82),and the corresponding sensitivity,specificity,positive predictive value and negative predictive value were 0.76,0.80,0.79,0.77,respectively.Conclusions:(1)There was no obvious abnormality in the overall developmental level of HR-ASD toddlers.(2)Similar to ASD toddlers,HR-ASD toddlers showed increased attention to the activities of the characters,but no interest in the characters when viewing social scenes with characters interacting.(3)Similar to ASD toddlers,HR-ASD toddlers had visual preference for non-social stimuli when viewing social and non-social stimuli presented simultaneously.(4)The visual preference of HR-ASD toddlers for non-social stimuli was effective in distinguishing the risk of ASD.