The Effect Of Autistic Traits On The Ensemble Perception Of Size In Typically Developing Individuals

Autism spectrum disorder(ASD)is a neurodevelopmental disorder.Individuals with ASD not only have deficits in social and cognitive aspects,but also have abnormalities in visual processing.In addition to individuals with ASD,families of ASD or typically developing(TD)individuals may also display behavioural characteristics and personality traits similar to those with ASD.Such behavioural characteristics and personality traits that below clinical diagnostic criteria are called sub-threshold autistic traits.Ensemble perception refers to the visual system’s ability to extract summary statistic information from groups of similar objects.According to the weak central coherence theory and Bayesian model of autistic perception,it speculated that ASD may have abnormalities in ensemble perception,but the finding still controversial.By exploring whether autistic traits in TD affect ensemble perception not only can further clarify this controversy and provide experimental evidence for the weak central coherence theory,Bayesian model of autistic perception,but also provide potential judgment indicators for ASD diagnosis.Therefore,three sub-studies were designed for this study.The Study 1,based on the Bayesian model of autistic perception,exploring the effects of autistic traits on direct ensemble perception of size.400 college students were selected to finish the Autism-Spectrum Quotient to measure the score of autistic traits.According to the scores of the questionnaire,20 participants were selected as the high autistic traits group,and 20 participants were selected as the low autistic traits group.The participants complete the mean estimation task based on the cross-spatial stimulus presentation.This task used the mean estimation error as the dependent variable to measure the performance of the participants’ ensemble perception.The result showed that:(1)The ensemble perception performance of the participants in the high autistic traits group was worse than the low autistic traits group.(2)The communication and social skills dimensions of autistic traits were significantly positively correlated with the mean estimation error.The Study 2,in order to made the presentation of stimuli more real and increased ecological validity of the study.Based on the participants,stimulus attributes and task form of Study 1,This study used the rapid serial visual presentation(RSVP)method to present stimuli to further explore the effect of autistic traits on direct ensemble perception of size.The result showed that:(1)There was no significant difference between the high autistic traits group and the low autistic trait group in the performance of ensemble perception.(2)In group with high autistic traits,the ensemble perception performance under the condition of RSVP was better than that under the condition of cross-spatial presentation.And in group with low autistic traits,the ensemble perception performance under the two conditions was not different.The Study 3,Based on the same theory as Study 1,the effects of autistic traits on automatic ensemble perception of size were explored.The study used the same participant and the participant complete the implicit member identity task based on RSVP.The task used the choice bias to the average stimuli as a dependent variable to represent the participant’s ensemble perception performance.The result showed that there was no significant difference in the automatic ensemble perception between the high autistic traits group and the low autistic traits group.In summary,When the task used the cross-spatial presentation to presented stimuli,the autistic traits of TD could affect the direct ensemble perception of size,specifically,the ensemble perception ability of individuals with high autistic traits is weaker than that of individuals with low autistic traits.However,when the task used the RSVP to presented stimuli,the autistic traits of TD had no effect on the direct and automatic ensemble perception of size.This finding provide experimental evidence for the refinement of weak central coherence theory and Bayesian model of autistic perception,and may also provide potential judgment indicators for ASD diagnosis.