The Effect Of Facial Abstraction On Emotional Face Processing In Children With Autism Spectrum Disorder

Individual's ability of emotional face processing is of vital important for their social interactions.Compared to typically developing(TD)controls,children with autism spectrum disorders(ASD)have emotional face processing deficits,which may contribute to difficulties in their social interactions.However,education practice shows that cartoon faces which are with higher level of facial abstraction seem to be different for children with ASD.In this study,two experiments were conducted to explore not only the differences of emotional face processing of faces with different levels of abstraction between children with ASD and TD children,but also the mechanism of eye movement.In experiment 1,24 children with ASD and 24 TD children(matched on nonverbal intelligence)were tested using a face emotion recognition task.The experiment adopted a 2(group: children with ASD,TD children)x 4(level of abstraction: real face,cartoon face with low abstraction,cartoon face with medium abstraction,cartoon face with high abstraction)x 5(emotion type: fear,anger,sadness,neutral,happiness)mixed design.The results revealed that:(1)children with ASD were less able to recognize the emotion of faces with different levels of abstraction than TD children,which was mainly reflected in real face,cartoon face with low abstraction and cartoon face with medium abstraction;(2)children's ability ranged from high to low in recognizing different emotions: positive emotion(happiness),neutral emotion,negative emotions(anger,sadness,fear).In order to further investigate the differences of gaze pattern between children with ASD and TD children,experiment 2 adopted eye tracking technology and recruited other 16 children with ASD and 16 TD children(matched on nonverbal intelligence).Compared to experiment 1,experiment 2 added a level of abstraction and cut two kinds of emotions(anger,fear).The participants were given implicit(face-viewing)and explicit tasks(face emotion recognition).The results showed that:(1)during the implicit task,compared to TD children,children with ASD had the same Time to First Fixation(TFF)and First Fixation Duration(FFD),while their Fixation Counts(FC)and Total Fixation Duration(TFD)were significantly shorter,which meant compared to TD children,children with ASD spent the same time to detect face but less time to fixate on emotional faces with different levels of abstraction;(2)during the explicit task,the behavior results was similar to experiment 1 and the results of eye movement showed that TFF of children with ASD was longer than TD children,while there were no significant difference between their FFD,FC or TFD.This suggested that children with ASD should take more time to detect emotional faces during facial emotion recognition,however,they had similar gaze pattern with TD children;(3)during implicit and explicit tasks,compared to the mouth region,both children with ASD and TD children showed larger FC and longer TFD of the eye region,which meant the two groups of children preferred to gaze at the eye region.In conclusion,this study confirmed that the processing of face emotion in children with ASD was different from TD children.It demonstrated that:(1)when participants were freely looking at emotional faces,children with ASD showed the same detection speed but less gaze interest of faces than TD children;(2)when participants recognized the emotion of faces,both children with ASD and TD children showed similar gaze pattern,however,children with ASD still had impairments in recognizing face emotion;(3)two groups of children had the advantage in emotion recognition of face with higher abstraction,but no difference between real face and cartoon face with low abstraction;(4)the ability of face emotion recognition was best of positive emotion,followed by neutral and negative emotions;(5)whatever the task was,children with ASD showed the same preference of eye region as TD children,and both groups could adjusted their gaze pattern according to different faces abstraction and emotions.According to Multi-Stages Integrative Model,the results suggested that the facial expression representation of children with ASD may be less clear and mature than that of TD children,and the representation's development of children with ASD may be different for each emotion.Therefore,we should pay attention to the development of facial expression representation of children with ASD and find their zone of proximal development.Then,we could using the appropriate materials(such as emotional faces with higher level of abstraction)to help them improve the ability of face emotion processing.