A Study On Category Perception Of Stop Aspiration And Tone In Chinese Autistic Children

In this study,the classic paragidm of categorical perception behavior experiment was used to investigate whether the Chinese autistic children’s perception of stop’s aspiration and tone had categorical characteristics.Four groups of 67 children were included in the study:24 autistic children aged 6-8,24 typically developing children aged 6-8,9 autistic children aged 10-12 and 10 typically developing children aged10-12.We conducted identification and discrimination experiments for both stop’s aspiration perception and tone perception.We measured the categorization level of stop’s aspiration and tone perception by recognition rate,category boundary,category width and discrimination accuracy.Taking typical children as the control group,the experiment explored the perceptual differences between autistic children and typical developing children,and explored the reasons.The speech material used in the experiment is a synthetic speech continuum.The stop’s aspiration perception experiment used a/bu/-/pu/speech continuum consisting of nine speech stimuli.Tone perception experiment used the/i/³⁵-/i/⁵⁵ phonetic continuum,which consists of 11phonetic stimuli.The perception experiment showed the following results:（1）In the stop’s aspiration identification experiment,the four groups of children all presented categorized perceptual features.The absolute slope of recognition curve in children with ASD was significantly higher than that in children with TD.The category width of children with ASD was significantly smaller than that of children with TD.There was no significant difference on the category boundary between children with ASD and children with TD.The absolute slope of the recognition curve of children aged 10-12 was significantly higher than that of children aged 6-8,and there was no significant difference in category boundaries and category widths among children of different ages.（2）In the stop’s aspiration discrimination experiment,the four groups of children all showed categorization perceptual characteristics.For the accuracy of between-category comparisons,ASD children aged 6-8 was significantly higher than TD children aged 6-8.（3）In the tone identification experiment,the four groups of children all showed categorization perceptual characteristics.The category boundaries of children in the ASD group were significantly smaller than those in the TD group.There was no significant difference between ASD children and TD children in category width and the absolute slope of the recognition curve.There were no significant differences in the absolute value of the slope of the recognition curve,the position of the category boundary and the width of the category boundary between the children aged 6-8 and10-12.（4）In the tone discrimination experiment,6-8 years old ASD children,6-8 years old TD children and 10-12 years old TD children showed categorization perceptual characteristics,while 10-12 years old ASD children lacked categorization perceptual characteristics.There was no significant effect of category type was found for children aged 10-12 with ASD,and the discrimination curve was flat,and the discrimination peak did not correspond to the category boundary.Based on the above experimental results,we draw the following conclusions:（1）Both ASD children and TD children had categorical perception of the stop’s aspiration.However,the category of ASD children’s perception of stop’s aspiration was stronger than that of TD children.（2）The tone perception of 6-8 year old ASD children,6-8 year old TD children and 10-12 year old TD children was categorical perception,but the tone discrimination of 10-12 year old ASD children lacked categorical characteristics.The categorization of tone perception in ASD children was weaker than that in TD children.（3）Low level perceptual advantage,local perceptual preference,and speech experience in ASD children affected their perception of stop’s aspiration and tone.