Study On The Characteristics Of Eye Track Fixation In Children With Autism Spectrum Disorders Aged 2-6 Years And The Establishment Of A Diagnostic And Predictive Model

Objective:To explore the eye tracking fixation characteristics of 2-6 years old children with autism spectrum disorder,to provide an objective index for early screening of ASD,and to construct a diagnostic and predictive model suitable for 2-6 years old ASD children,and to provide an auxiliary tool for clinical diagnosis.Method:There are two parts in this study.Part one:Analysis of characteristics of eye tack fixation in ASD children aged 2-6 years.A case-control study was conducted between May 2017 and January 2018 in the Department of Psychology and Rehabilitation of Children in Shenzhen Maternity and Child Healthcare Hospital(MCH)and a kindergarten in Shenzhen.Using eye tracking to test two groups of children watching video depictions of specific objects.That is,?.Character face video(0-30 seconds).?.Forward and inverted Biological movements in Video(30-60seconds).?.The dynamic geometry and the dynamic character are presented at the same time(60-90seconds).iv.Character dynamic common attention(90-120seconds)were assigned to eye track fixation count(FC,)and the fixation time(FT),the percentage of fixation time(TFT%)and by using Autism rating scale(CARS)and Autism observation scale(ADOS)to evaluate the children with ASD.Microsoft Excel2007 table is used to input data.SPSS20.0 statistical analysis.First of all,the ASD group and TD group of children with various eye track fixation indicators were analyzed by t-test and chi-square test.Then,Correlation analysis between eye track fixation index and its behavior index with statistical significance.Part two:Establishment of a predictive model for the diagnosis of eye tack fixation characteristics in children aged 2-6 years with ASD:for the eye track fixation index with statistical significance in the first part of t-test and chi-square test,the Fisher linear discriminant prediction model was constructed by stepwise discriminant method,which was used to distinguish the individual of ASD.Result:A total of 210 samples were collected.There was no significant difference in age and sex between the two groups.Part one:Analysis of eye tracking fixation characteristics in children with ASD.Within 30 seconds of i person's facial video,Compared with TD group,the TFT%of ASD group was significantly shorter than that of TD group,and with the increase of the time of stimulation,the FT,FC of ASD group decreased gradually(P<0.05)and the TFT%of the dynamic mouth of ASD group increased obviously with the increase of stimulation time.The FC,FT of dynamic mouth increased gradually(P<0.05);Within 30 seconds of ii Biological motion video,TFT%in ASD group was compared with TD group.With the increase of stimulation time,the FT,FC of children in ASD group showed an increasing trend to reverse biological movement,while that of TD group to positive biological movement showed a downward trend,and the eye tack FC,FT of ASD group to positive biological movement increased gradually with the increase of stimulation time,and then decreased sharply with the increase of stimulation time.But the TD group showed a steady upward trend,and the difference between the two groups was statistically significant(P<0.05).Within 30 seconds of iii the video of dynamic character and geometry,TFT%in ASD group was significantly higher than that in TD group(P<0.05),but it was shorter in dynamic character group than that in TD group,and decreased gradually with the increase of stimulation time(P<0.05).However,the FT of dynamic geometry in both groups showed a similar increasing trend.The difference was not significant(P>0.05).Within 30 seconds of ivthe video of dynamic joint attention,TFT%of eye orientation in ASD group was significantly shorter than that in TD group(P<0.05).With the increase of stimulation time,the FC,FT of TD group was gradually increased,but that of ASD group was stable.There was a significant difference between the two groups(P<0.05).The correlation analysis of eye track fixation index with CARS scale and ADOS scale in ASD group was carried out.The score of CARS scale and the number of eye track fixation of dynamic mouth were r=0.26 and r=0.35 respectively.The percentage of fixation time was rs=-0.51,and the time of eye track fixation was also observed in(r=-0.51).The percentage of fixation time was negatively correlated with that of TFT%,(rs=-0.49,P<0.05).There was no correlation with the times of inverted dynamic biological fixation(P<0.05).There was a positive correlation between TFT and the percentage of fixation time of dynamic geometry.There was no significant correlation between other eye track fixation indexes and CARS scale(P>0.05).The percentage of the time of social interaction and dynamic mouth eye movement and fixation was r=0.49 and the number of times of dynamic geometry eye track fixation was r=0.37 and the percentage of fixation time was rs=0.30.there was a positive correlation(P<0.05).There was a negative correlation with the percentage of eye fixation time(TFT).There was no significant correlation with the other indexes of eye tack(P>0.05).The percentage of the time of communication and dynamic eye track fixation of the mouth was not significant(P= 0.024).The number of oculomotor fixation was 0.078 and the fixation time was r=0.44.There was a positive correlation between the percentage of fixation time(rs=0.43,P<0.05).There was no significant correlation between the total score of ADOS and the other indexes of eyetracking.The correlation between the total score of ADOS and the index of eye tracking showed that the total score of the scale and the percentage of eye track fixation time were significant.The percentage of eye track fixation time(FT)was r=-0.41.There was a negative correlation(P<0.05)in the percentage of eye track fixation time(P<0.05)between the two groups(P<0.05).There was a positive correlation with the percentage of eye track fixation time(FT)of the dynamic geometry(P<0.05),but no significant correlation with the other indexes of eye tracking.Part two:Establishment of the model:The final indicators included in the model are:static eye fixation time percentage,reverse biological motion fixation points,reverse biological motion fixation time,and common attention to fixation points,and functional formula of discriminant analysis and prediction model of ASD Multiple eye tracking system is Z=-1.709-0.003eX3+0.086dX1+0.001dX2-0.051aX1.When Zi>0.66,it was judged to be normal;when Zi<0.66,it was judged to be ASD,and the rate of self identification and discrimination was 71.1%.The area under the ROC curve of discriminant analysis model was AUC=0.61,the sensitivity was 68.9%,and the specificity was 72.4%.Conclusion:children with ASD aged 2 to 6 years showed different eye tracking fixation characteristics.These characteristics are related to the degree of symptoms and social interaction.The discriminant analysis model can distinguish and predict ASD individuals from the perspective of epidemiology.