AbstractThe present thesis aimed to examine if children with ASD process emotions comparably to TD children or if they show emotion processing difficulties, with particular focus on the recognition- and imitation of facial emotional expressions and on processing human faces. Furthermore, the thesis sought to contrast the performance of children (both with- and without ASD) with that of neurotypical adult participants to establish the typical level of emotion processing and to investigate if emotion processing capabilities improve with age from childhood to adulthood.
Experiment 1 tested the recognition of the six basic emotions (anger, disgust, fear, happiness, sadness and surprise, and also neutrality) under timed conditions, when restricted stimulus presentation length- (1200ms, 200ms, no limit) and increased pressure to respond were introduced (1200ms limit, no limit), as well. In addition, the experiment compared participants’ performance from human facial expressions and from the expressions of animated characters. The Animated Characters Stimulus Set has been developed and validated before the main experiment. The overall performance of children with ASD was comparable to that of TD children, whose superiority only emerged with the introduction of additional task demands through limiting the length of stimuli presentation or applying a temporal restriction on the response window. Using animated characters to present emotions, instead of human actors, however, improved emotion recognition and alleviated the difficulty of additional task demands, especially for children with ASD, when facial expressions were only briefly presented.
Experiment 2 tested the effects of face inversion and in-plane rotations (from 0° to 330°, in 30° increments) on the recognition of the six basic emotions (and neutrality). Children with ASD and TD children recognised emotions with comparable accuracy, while neurotypical adults have outperformed the two child groups. Overall, emotion recognition decreased gradually as rotations approached full inversion; although, this pattern was most prominent in typical adults, whereas the emotion recognition of TD children and especially children with ASD varied considerably across rotations. In contrast to adults and TD children, inversion effects were only found in children with ASD when they observed negative- or more complex emotions, thereby showing evidence both for the availability of configural face processing and for the use of feature-based strategies.
Experiment 3 tested imitative behaviour by comparing performance on emotional facial expressions (reflecting anger, disgust, fear, happiness, sadness and surprise, and also neutrality), and non-emotional facial gestures and bilateral bodily actions/movements, presented in short video clips. The style of the imitation was also examined (subtle- vs strong stimulus intensity). A video stimulus set was developed and validated for the purpose of the experiment with a series of pilot studies. Results showed that the imitations of children with ASD were less intense than those of TD children and typical adults only when the participants were copying emotional facial expressions but not when they reproduced non-emotional facial and bodily actions. Moreover, children with ASD were less able to copy the style of the presented actions (only for the imitation of emotional facial expressions) than the two neurotypical groups.
Overall, the present thesis demonstrated that the emotion processing of children with ASD was consistently comparable to TD children’s, when their performance was contrasted in experimental, facial emotion recognition and face processing tasks, and in a behavioural study, which assessed their imitations of emotional facial expressions. On the other hand, it was also shown that the emotion processing of children with ASD involved atypical features both when they were recognising- and reproducing emotions. Compared to TD children, they showed increased sensitivity to the negative effects of additional task difficulties and their advantage in utilising featural face processing strategies seemed to be greater, as well, while they were less able to imitate the exact style of the presented emotional facial expressions. These findings support a number of theoretical approaches; however, the notion of an early deficit in social motivation seems to be both appealing and promising in studying and developing socio-emotional functioning in ASD as its perspective could be beneficial to reflect on and possibly affect multiple underlying features.
|Date of Award||2017|
|Supervisor||Emese Nagy (Supervisor)|
- Autism spectrum disorder
- Emotion recognition