The Level of Intelligence Modulates the Recognition of Emotional Point-Light Displays in Children with Autism Spectrum Disorder (ASD): A Comparison Between High Functioning and Low Functioning ASD
The moving human body is a nuance-rich cue of others’ attitude: patients with Autism Spectrum Disorder (ASD) often fail to figure out its meaning and show anomalous pattern of brain activation during motion perception. Besides, their ability to recognize emotion is generally impaired, especially when conveyed by biological elements – motion included. Point Light displays (PLD) are reliable tools to assess the ability to identify the emotion shown through a moving human body. Evidence in the literature mostly involves high-functioning (HF) ASD samples and there is a lack of information on low-functioning (LF) ASD population’s abilities. It is still debated if the ASD’s impairment in social interaction is related to the processing of biological motion (BM), besides it is unclear the relation between emotion recognition and IQ level.
We explored the ability to understand BM with different emotional valence in children with ASD. We enquired if their impairment was specific for the recognition of emotions or widespread to BM in general. Moreover, we explored the role played by the IQ level in this ability.
24 typically-developing (TD) children, 23 children with HF ASD and 17 with LF ASD took part in our study. Respectively, the mean age and IQ of each group were 9.05, 111; 9.5,100; 12.2,49. After each PLD clip, we asked the children to categorize the emotion (fear, happiness, neutral) by pressing the corresponding key. Emotional categories were presented coupled in three separated blocks. The dichotomous choice allowed also LF ASD children to perform the task. Accuracy and response times (RTs) were measured.
Total accuracy was significantly different according with the functioning: TD children outperformed children with ASD, children with HF ASD showed higher levels of accuracy than children with LF ASD. A positive correlation between accuracy and IQ was found in all the groups, though the generalized linear model which takes IQ into account explained accuracy only in the two ASD groups.
Considering RTs relative to recognized stimuli, TD were significantly faster than ASD; no differences emerged between HF and LF ASD groups. IQ resulted negatively correlated with rapidity and significantly predicted it in the generalized linear model for all the three groups.
Comparing performances between the three emotional categories: TD were significantly more accurate and faster in recognizing of all the three classes of stimuli, while no differences between ASD groups emerged.
Our findings suggests that the ability to recognize the emotional meaning of BM is impaired in ASD children, independently of its emotional content.
Cognitive level seems pivotal for recognizing affective biological motion in children with ASD. Although IQ doesn’t seems to impact the accuracy of this mechanism when it works properly, it is important when the mechanism is impaired. A more efficient cognitive substrate might mediate the acquisition of compensatory mechanisms, which help ASD children to better understand the human gestures. Besides, for all participants IQ is important for promptly recognize the stimuli. Therefore, the IQ level seems to mediate the efficiency of the biological motion processing, boosting its rapidity.